Patent Application
20240298276
This disclosure relates generally to wireless communication, and more specifically, to power transmission management for multiple-input multiple-output (MIMO) and smart antenna systems operating in channels with power or power spectral density (PSD) restrictions.
A wireless local area network (WLAN) may be formed by one or more wireless access points (APs) that provide a shared wireless communication medium for use by multiple client devices also referred to as wireless stations (STAs). The basic building block of a WLAN conforming to the Institute of Electrical and Electronics Engineers (IEEE) 802.11 family of standards is a Basic Service Set (BSS), which is managed by an AP. Each BSS is identified by a Basic Service Set Identifier (BSSID) that is advertised by the AP. An AP periodically broadcasts beacon frames to enable any STAs within wireless range of the AP to establish or maintain a communication link with the WLAN.
When a wireless communication device such as an AP or a STA has data to transmit, the wireless communication device transmissions may be subject to power limitations. Such transmission limits can include both power spectral density limitations, as well as effective isotropic radiated power (EIRP) limitations. For arrays of antennas, power limitations can be based on a total power being transmitted on all antennas in a given channel, and can further be based on whether transmissions on different antennas are correlated or uncorrelated. Because the transmit power is directly associated with key device characteristics, such as coverage area for a device to receive transmissions from an access point (AP) or wireless station (STA), selection of gain settings associated with power transmission can greatly impact device performance.
The systems, methods and devices of this disclosure each have several innovative aspects, no single one of which is solely responsible for the desirable attributes disclosed herein.
One innovative aspect of the subject matter described in this disclosure can be implemented in a method for wireless communication. The method includes: determining first transmission power levels for a first set of one or more antennas and second transmission power levels for a second set of one or more antennas based on a polarization diversity setting for a wireless communication device, the polarization diversity setting being based on a first orientation of the first set of one or more antennas being orthogonal to a second orientation of the second set of one or more antennas; transmitting, to a target device, first signals at the first transmission power levels using the first set of one or more antennas; and transmitting, to the target device, second signals at the second transmission power levels using the second set of one or more antennas, the first signals being cross-polarized from the second signals based on the first orientation being orthogonal to the second orientation.
Another innovative aspect of the subject matter described in this disclosure can be implemented in a wireless communication device. The wireless communication device includes: at least one modem; a first set of one or more antennas communicatively coupled to the at least one modem and having a first orientation; a second set of one or more antennas communicatively coupled to the at least one modem and having a second orientation that is orthogonal to the first orientation; at least one processor communicatively coupled with the at least one modem; and at least one memory communicatively coupled with the at least one processor and storing processor-readable code that, when executed by the at least one processor in conjunction with the at least one modem, that is configured to: determine first transmission power levels for the first set of one or more antennas and second transmission power levels for the second set of one or more antennas based on a polarization diversity setting for the wireless communication device, the polarization diversity setting being based on the first orientation of the first set of one or more antennas being orthogonal to the second orientation of the second set of one or more antennas; transmit, to a target device, first signals at the first transmission power levels using the first set of one or more antennas; and transmit, to the target device, second signals at the second transmission power levels using the second set of one or more antennas, the first signals being cross-polarized from the second signals based on the first orientation being orthogonal to the second orientation.
In some implementations, the methods and wireless communication devices may be configured to: determine the polarization diversity setting for one or more communications, the polarization diversity setting indicating that the first signals and the second signals are cross-polarized signals; determine antenna assignments for one or more communications at least in part by assigning the first set of one or more antennas and the second set of one or more antennas to the one or more communications; and select the first transmission power levels for the first set of one or more antennas and the second transmission power levels for the second set of one or more antennas based on the polarization diversity setting and the antenna assignments.
In some implementations, the methods and wireless communication devices may be configured to: determine a first array gain for the first set of one or more antennas based on the antenna assignments; determine a second array gain for the second set of one or more antennas based on the antenna assignments; and determine a transmission power level for each antenna of the first set of one or more antennas based on the first array gain and for each antenna of the second set of one or more antennas based in the second array gain.
Additional aspects are included in the detailed description below.
Details of one or more aspects of the subject matter described in this disclosure are set forth in the accompanying drawings and the description below. However, the accompanying drawings illustrate only some typical aspects of this disclosure and are therefore not to be considered limiting of its scope. Other features, aspects, and advantages will become apparent from the description, the drawings and the claims.
Like reference numbers and designations in the various drawings indicate like elements.
The following description is directed to some particular examples for the purposes of describing aspects of this disclosure. However, a person having ordinary skill in the art will readily recognize that the teachings herein can be applied in a multitude of different ways. Some or all of the described examples may be implemented in any device, system or network that is capable of transmitting and receiving radio frequency (RF) signals according to one or more of the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards, the IEEE 802.15 standards, the Bluetooth® standards as defined by the Bluetooth Special Interest Group (SIG), or the Long Term Evolution (LTE), 3G, 4G or 5G (New Radio (NR)) standards promulgated by the 3rd Generation Partnership Project (3GPP), among others. The described aspects can be implemented in any device, system or network that is capable of transmitting and receiving RF signals according to one or more of the following technologies or techniques: code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), single-user (SU) multiple-input multiple-output (MIMO) and multi-user (MU)-MIMO. The described aspects also can be implemented using other wireless communication protocols or RF signals suitable for use in one or more of a wireless personal area network (WPAN), a wireless local area network (WLAN), a wireless wide area network (WWAN), or an internet of things (IOT) network.
The above wireless communication systems are subject to regulatory limits on the amount of power transmitted by devices in a system. Such limits can include specific limitations on the amount of power transmitted into frequency channels (e.g., power spectral density limits) as well as limitations on power radiated by antennas (e.g., equivalent isotopically radiated power (EIRP)). For antenna arrays or multiple antenna systems, the power radiated by each antenna into a given channel is considered for such power limitations. For highly correlated signals on different antennas being transmitted at the same time, the transmitters must reduce per-antenna power to meet power spectral density (PSD) and EIRP limits, as the correlated signals can combine to exceed the limits. Beamformed or steered signals are examples of correlated signals transmitted during a shared time period that result in a reduction of per-antenna power transmission. The power limits result in certain aspects of performance gains from MIMO transmission being nullified, as the antenna array gain from the use of multiple antennas is offset by reduced power to the individual antennas to meet PSD and EIRP limits.
By contrast, separate signals where the data in the signals are not statistically related (e.g., uncorrelated) do not combine in the wireless transmission medium in the same way as correlated signals, and so the above described PSD and EIRP limits on arrays of antennas are associated with higher antenna array gain settings and higher transmit power when matched to uncorrelated signals. Further, when antennas in an array are mutually orthogonal (e.g., transmitting in a geometry distinct from each other, such as in orthogonal x, y, and z planes of a cartesian coordinate system), the signals can be treated as uncorrelated, even if the data of the signals is identical or highly statistically similar. When the signals reflect of surfaces in an environment, the signals lose their polarization. The loss of polarization allows the signals to be received as correlated signals at a target device (e.g., after the reflections), while the signals are uncorrelated at the transmitting device (e.g., before the reflections.)
Various aspects relate generally to the use of mutually orthogonal MIMO antenna systems by a wireless communication device (e.g., an access point (AP) or a station (STA)) for transmitting cross-polarized signals (also referred to as orthogonally polarized signals) from mutually orthogonal antennas at the wireless communication device. For example, the wireless communication device can use the cross-polarized signals for performing beamforming or steering. In some examples, a wireless communication device can determine or select specific transmission power levels at individual antennas of a mutually-orthogonal antenna system for beamforming or steering transmissions by determining that polarization diversity is supported (e.g., mutually-orthogonal antennas are available for use), and then determining antenna array gain settings from static (e.g., a control table) or dynamic (e.g., computed per-packet) elements. The wireless communication can then determine the transmission power levels at the individual antennas of the mutually orthogonal antenna system using the gain settings.
As noted above, in some aspects, a wireless communication device (e.g., an AP or STA) can select antenna array gain settings for polarization diversity using a control table. The control table can include entries for each unique combination of transmitters (e.g., antennas), simultaneous streams of data, and one or more band channels for when polarization diversity is enabled and disabled. An example of a control table is illustrated in table 2 below. In some aspects, a wireless communication device can set an array gain using both static values from a control table and dynamic array gain contributions that are contributed on a per packet bases for streams of data. For implementations with multiple antennas in a given direction (e.g., non-orthogonal antennas), the wireless communication device can use masks that indicate how signals are allocated among the different antennas. In one illustrative example, for a wireless communication device with eight antennas divided among three orthogonal directions, a first direction can be associated with three antennas, a second direction can be associated with three antennas, and a third direction can be associated with the remaining two antennas. A control table and associated masks can indicate how given signals are transmitted. For example, with polarization diversity enabled for the wireless communication device with the eight antennas, the wireless communication device can configure (e.g., based on the control table and associated masks) the transmission of three signals (e.g., each to be transmitted on a unique channel or frequency range). The wireless communication device can allocate the three signals among the eight antennas so that two of the signals are each transmitted using three antennas each (e.g., one from each direction) and the third signal is transmitted using the two remaining orthogonal antennas. With such an allocation, each of the three signals are transmitted on groups of mutually orthogonal antennas such that a back off is not needed in order to comply with power limits for the corresponding channel used for each signal. The wireless communication device can transmit the first signal on three antennas, each mutually orthogonal (e.g., an Hx, an Hy, and a Vx orientation), so that each antenna used to transmit the first signal has a different orientation. The wireless communication device can transmit the second signal on three additional antennas, different than the three antennas used for the first signal, with each of the three additional antennas also being mutually orthogonal from each other (e.g., an Hx, an Hy, and a Vx orientation). The wireless communication device can transmit the third signal using the two remaining unused antennas of the device's eight antennas, which are orthogonal from each other (e.g., an Hx and Hy orientation, an Hx and Vx orientation, or an Hy and Vx orientation).
Particular aspects of the subject matter described in this disclosure can be implemented to realize one or more of the following potential advantages. In some examples, by using mutually orthogonal antennas for transmitting cross-polarized (or orthogonally polarized) signals, a wireless communication device (e.g., an AP or STA) can increase transmission power while conforming with PSD and EIRP limits, such as those described above. For example, by transmitting the correlated signals on mutually orthogonal antennas, a wireless communication device can maintain the power benefits of multiple antennas while complying with PSD and EIRP limits due to the wireless signals being uncorrelated near the wireless communication device (e.g., prior to reflections). Such transmissions improve the performance of a wireless communication device (e.g., signal coverage, throughput, etc.) while maintaining compliance with wireless communication system power limits. According to aspects described herein, a wireless communication device can transmit correlated data on different antennas in a manner that can ensure that the wireless signals are not correlated near the wireless communication device, due to the polarization of the antennas being mutually orthogonal at the wireless communication device. In such aspects, at the wireless communication device where the PSD and EIRP values are most problematic, the wireless transmissions on the mutually orthogonal antennas do not interact in a problematic fashion. Based on such aspects, a receiving device can receive the cross-polarized or orthogonally polarized signals in the same fashion as a directly beamformed signal (e.g., due to environmental reflections). For instance, a receiving device can receive reflected transmissions of data correlated signals transmitted by orthogonal antennas of the mutually-orthogonal antenna system and can use the received transmissions as a beamformed signal, since the polarization of the transmitted signals is lost as the signals are reflected. Communications systems integrating such aspects can have increased coverage area (e.g., with fewer devices needed for a given coverage area) and can have improved communication performance (e.g., received signal strength indication performance or MIMO channel correlation performance) in environments with manifold reflections (e.g., indoor environments) involving rich scattering with significant numbers of reflective surfaces where orthogonally transmitted signals are reflected to a receiving device as a received MIMO communication.
Each of the STAs 104 also may be referred to as a mobile station (MS), a mobile device, a mobile handset, a wireless handset, an access terminal (AT), a user equipment (UE), a subscriber station (SS), or a subscriber unit, among other examples. The STAs 104 may represent various devices such as mobile phones, personal digital assistant (PDAs), other handheld devices, netbooks, notebook computers, tablet computers, laptops, display devices (for example, TVs, computer monitors, navigation systems, among others), music or other audio or stereo devices, remote control devices (“remotes”), printers, kitchen or other household appliances, key fobs (for example, for passive keyless entry and start (PKES) systems), among other examples.
A single AP 102 and an associated set of STAs 104 may be referred to as a basic service set (BSS), which is managed by the respective AP 102.
To establish a communication link 108 with an AP 102, each of the STAs 104 is configured to perform passive or active scanning operations (“scans”) on frequency channels in one or more frequency bands (for example, the 2.4 GHz, 5 GHZ, 6 GHz or 60 GHz bands). To perform passive scanning, a STA 104 listens for beacons, which are transmitted by respective APs 102 at a periodic time interval referred to as the target beacon transmission time (TBTT) (measured in time units (TUs) where one TU may be equal to 1024 microseconds (μs)). To perform active scanning, a STA 104 generates and sequentially transmits probe requests on each channel to be scanned and listens for probe responses from APs 102. Each STA 104 may be configured to identify or select an AP 102 with which to associate based on the scanning information obtained through the passive or active scans, and to perform authentication and association operations to establish a communication link 108 with the selected AP 102. The AP 102 assigns an association identifier (AID) to the STA 104 at the culmination of the association operations, which the AP 102 uses to track the STA 104.
As a result of the increasing ubiquity of wireless networks, a STA 104 may have the opportunity to select one of many BSSs within range of the STA or to select among multiple APs 102 that together form an extended service set (ESS) including multiple connected BSSs. An extended network station associated with the WLAN 100 may be connected to a wired or wireless distribution system that may allow multiple APs 102 to be connected in such an ESS. As such, a STA 104 can be covered by more than one AP 102 and can associate with different APs 102 at different times for different transmissions. After association with an AP 102, a STA 104 also may be configured to periodically scan its surroundings to find a more suitable AP 102 with which to associate. For example, a STA 104 that is moving relative to its associated AP 102 may perform a “roaming” scan to find another AP 102 having more desirable network characteristics such as a greater received signal strength indicator (RSSI) or a reduced traffic load.
In some cases, STAs 104 may form networks without APs 102 or other equipment other than the STAs 104 themselves. One example of such a network is an ad hoc network (or wireless ad hoc network). Ad hoc networks may alternatively be referred to as mesh networks or peer-to-peer (P2P) networks. In some cases, ad hoc networks may be implemented within a larger wireless network such as the WLAN 100. In such aspects, while the STAs 104 may be capable of communicating with each other through the AP 102 using communication links 108, STAs 104 also can communicate directly with each other via direct wireless links 110. Two STAs 104 may communicate via a direct communication link 110 regardless of whether both STAs 104 are associated with and served by the same AP 102. In such an ad hoc system, one or more of the STAs 104 may assume the role filled by the AP 102 in a BSS. Such a STA 104 may be referred to as a group owner (GO) and may coordinate transmissions within the ad hoc network. Examples of direct wireless links 110 include Wi-Fi Direct connections, connections established by using a Wi-Fi Tunneled Direct Link Setup (TDLS) link, and other P2P group connections.
The APs 102 and STAs 104 may function and communicate (via the respective communication links 108) according to the IEEE 802.11 family of wireless communication protocol standards (such as that defined by the IEEE 802.11-2016 specification or amendments thereof including, but not limited to, 802.11ay, 802.11ax, 802.11az, 802.11ba and 802.11be). These standards define the WLAN radio and baseband protocols for the PHY and medium access control (MAC) layers. The APs 102 and STAs 104 transmit and receive wireless communications (hereinafter also referred to as “Wi-Fi communications”) to and from one another in the form of PHY protocol data units (PPDUs) (or physical layer convergence protocol (PLCP) PDUs). The APs 102 and STAs 104 in the WLAN 100 may transmit PPDUs over an unlicensed spectrum, which may be a portion of spectrum that includes frequency bands traditionally used by Wi-Fi technology, such as the 2.4 GHz band, the 5 GHz band, the 60 GHz band, the 3.6 GHz band, and the 900 MHz band. Some implementations of the APs 102 and STAs 104 described herein also may communicate in other frequency bands, such as the 6 GHz band, which may support both licensed and unlicensed communications. The APs 102 and STAs 104 also can be configured to communicate over other frequency bands such as shared licensed frequency bands, where multiple operators may have a license to operate in the same or overlapping frequency band or bands.
Each of the frequency bands may include multiple sub-bands or frequency channels. For example, PPDUs conforming to the IEEE 802.11n, 802.11ac, 802.11ax and 802.11be standard amendments may be transmitted over the 2.4, 5 GHz or 6 GHz bands, each of which is divided into multiple channels (e.g., 20 megahertz (MHz) channels, 160 MHz channels, etc.).
As described above, some communication systems can be configured for multiple-input-multiple output (MIMO) operation to increase the capacity of a radio link using multiple transmission antennas and receiving antennas to exploit multipath propagation. In MIMO operation, multiple signals are transmitted simultaneously over a single radio channel (e.g., a defined frequency range). As described herein, MIMO transmissions using mutually orthogonal antenna placements can be performed with the signals on the orthogonal antennas treated as uncorrelated signals due to the positioning of the antennas.
Similarly, “smart antenna” systems can use beamforming or spatial filtering for directional signal transmission. Such smart antenna array systems transmit correlated signals on separate antennas within the “smart antenna” system, relying on constructive and destructive interference patterns to provide desired signal reception characteristics. As described herein, such signals for beamforming when sent on antennas with a shared direction (e.g., non-orthogonal) are subject to power reductions due to the separate antennas sending correlated signals on a single channel. Such signals, when sent on a shared channel using mutually orthogonal antennas, can be treated as uncorrelated signals, even if the data in the signals is correlated, due to the characteristics of transmission over mutually orthogonal antennas. Polarization diversity as described herein can be used with both MIMO systems and “smart antenna” systems (e.g., using digital or hybrid beamforming) to improve communication system performance, particularly in indoor environments, or environments when reflections are sufficient to create reflections from the mutually orthogonal antennas that will arrive at a target receiver.
As described above, the data in such communication systems can be structured as PPDUs. Each PPDU is a composite structure that includes a PHY preamble and a payload in the form of a PHY service data unit (PSDU). The information provided in the preamble may be used by a receiving device to decode the subsequent data in the PSDU. In instances in which PPDUs are transmitted over a bonded channel, the preamble fields may be duplicated and transmitted in each of the multiple component channels. The PHY preamble may include both a legacy portion (or “legacy preamble”) and a non-legacy portion (or “non-legacy preamble”). The legacy preamble may be used for packet detection, automatic gain control and channel estimation, among other uses. The legacy preamble also may generally be used to maintain compatibility with legacy devices. The format of, coding of, and information provided in the non-legacy portion of the preamble is based on the particular IEEE 802.11 protocol to be used to transmit the payload.
The L-STF 206 generally enables a receiving device to perform coarse timing and frequency tracking and automatic gain control (AGC). The L-LTF 208 generally enables a receiving device to perform fine timing and frequency tracking and also to perform an initial estimate of the wireless channel. The L-SIG 210 generally enables a receiving device to determine a duration of the PDU and to use the determined duration to avoid transmitting on top of the PDU. For example, the L-STF 206, the L-LTF 208 and the L-SIG 210 may be modulated according to a binary phase shift keying (BPSK) modulation scheme. The payload 204 may be modulated according to a BPSK modulation scheme, a quadrature BPSK (Q-BPSK) modulation scheme, a quadrature amplitude modulation (QAM) modulation scheme, or another appropriate modulation scheme. The payload 204 may include a PSDU including a data field (DATA) 214 that, in turn, may carry higher layer data, for example, in the form of medium access control (MAC) protocol data units (MPDUs) or an aggregated MPDU (A-MPDU).
The legacy portion 302 of the preamble includes an L-STF 308, an L-LTF 310, and an L-SIG 312. The non-legacy portion 304 includes a repetition of L-SIG (RL-SIG) 314, a first HE signal field (HE-SIG-A) 316, an HE short training field (HE-STF) 320, and one or more HE long training fields (or symbols) (HE-LTFs) 322. For OFDMA or MU-MIMO communications, the second portion 304 further includes a second HE signal field (HE-SIG-B) 318 encoded separately from HE-SIG-A 316. HE-STF 320 may be used for timing and frequency tracking and AGC, and HE-LTF 322 may be used for more refined channel estimation. Like the L-STF 308, L-LTF 310, and L-SIG 312, the information in RL-SIG 314 and HE-SIG-A 316 may be duplicated and transmitted in each of the component 20 MHz channels in instances involving the use of a bonded channel. In contrast, the content in HE-SIG-B 318 may be unique to each 20 MHz channel and target specific STAs 104.
RL-SIG 314 may indicate to HE-compatible STAs 104 that the PPDU 300 is an HE PPDU. An AP 102 may use HE-SIG-A 316 to identify and inform multiple STAs 104 that the AP has scheduled UL or DL resources for them. For example, HE-SIG-A 316 may include a resource allocation subfield that indicates resource allocations for the identified STAs 104. HE-SIG-A 316 may be decoded by each HE-compatible STA 104 served by the AP 102. For MU transmissions, HE-SIG-A 316 further includes information usable by each identified STA 104 to decode an associated HE-SIG-B 318. For example, HE-SIG-A 316 may indicate the frame format, including locations and lengths of HE-SIG-Bs 318, available channel bandwidths and modulation and coding schemes (MCSs), among other examples. HE-SIG-A 316 also may include HE WLAN signaling information usable by STAs 104 other than the identified STAs 104.
HE-SIG-B 318 may carry STA-specific scheduling information such as, for example, STA-specific (or “user-specific”) MCS values and STA-specific RU allocation information. In the context of DL MU-OFDMA, such information enables the respective STAs 104 to identify and decode corresponding resource units (RUs) in the associated data field 324. Each HE-SIG-B 318 includes a common field and at least one STA-specific field. The common field can indicate RU allocations to multiple STAs 104 including RU assignments in the frequency domain, indicate which RUs are allocated for MU-MIMO transmissions and which RUs correspond to MU-OFDMA transmissions, and the number of users in allocations, among other examples. The common field may be encoded with common bits, CRC bits, and tail bits. The user-specific fields are assigned to particular STAs 104 and may be used to schedule specific RUs and to indicate the scheduling to other WLAN devices. Each user-specific field may include multiple user block fields. Each user block field may include two user fields that contain information for two respective STAs to decode their respective RU payloads in data field 324.
The legacy portion 352 of the preamble includes an L-STF 358, an L-LTF 360, and an L-SIG 362. The non-legacy portion 354 of the preamble includes an RL-SIG 364 and multiple wireless communication protocol version-dependent signal fields after RL-SIG 364. For example, the non-legacy portion 354 may include a universal signal field 366 (referred to herein as “U-SIG 366”) and an EHT signal field 368 (referred to herein as “EHT-SIG 368”). One or both of U-SIG 366 and EHT-SIG 368 may be structured as, and carry version-dependent information for, other wireless communication protocol versions beyond EHT. The non-legacy portion 354 further includes an additional short training field 370 (referred to herein as “EHT-STF 370,” although it may be structured as, and carry version-dependent information for, other wireless communication protocol versions beyond EHT) and one or more additional long training fields 372 (referred to herein as “EHT-LTFs 372,” although they may be structured as, and carry version-dependent information for, other wireless communication protocol versions beyond EHT). EHT-STF 370 may be used for timing and frequency tracking and AGC, and EHT-LTF 372 may be used for more refined channel estimation. Like L-STF 358, L-LTF 360, and L-SIG 362, the information in U-SIG 366 and EHT-SIG 368 may be duplicated and transmitted in each of the component 20 MHz channels in instances involving the use of a bonded channel. In some implementations, EHT-SIG 368 may additionally or alternatively carry information in one or more non-primary 20 MHz channels that is different than the information carried in the primary 20 MHz channel.
EHT-SIG 368 may include one or more jointly encoded symbols and may be encoded in a different block from the block in which U-SIG 366 is encoded. EHT-SIG 368 may be used by an AP to identify and inform multiple STAs 104 that the AP has scheduled UL or DL resources for them. EHT-SIG 368 may be decoded by each compatible STA 104 served by the AP 102. EHT-SIG 368 may generally be used by a receiving device to interpret bits in the data field 374. For example, EHT-SIG 368 may include RU allocation information, spatial stream configuration information, and per-user signaling information such as MCSs, among other examples. EHT-SIG 368 may further include a cyclic redundancy check (CRC) (for example, four bits) and a tail (for example, 6 bits) that may be used for binary convolutional code (BCC). In some implementations, EHT-SIG 368 may include one or more code blocks that each include a CRC and a tail. In some aspects, each of the code blocks may be encoded separately by a device.
EHT-SIG 368 may carry STA-specific scheduling information such as, for example, user-specific MCS values and user-specific RU allocation information. EHT-SIG 368 may generally be used by a receiving device to interpret bits in the data field 374. In the context of DL MU-OFDMA, such information enables the respective STAs 104 to identify and decode corresponding RUs in the associated data field 374. Each EHT-SIG 368 may include a common field and at least one user-specific field. The common field can indicate RU distributions to multiple STAs 104, indicate the RU assignments in the frequency domain, indicate which RUs are allocated for MU-MIMO transmissions and which RUs correspond to MU-OFDMA transmissions, and the number of users in allocations, among other examples. The common field may be encoded with common bits, CRC bits, and tail bits. The user-specific fields are assigned to particular STAs 104 and may be used to schedule specific RUs and to indicate the scheduling to other WLAN devices. Each user-specific field may include multiple user block fields. Each user block field may include, for example, two user fields that contain information for two respective STAs to decode their respective RU payloads.
The presence of RL-SIG 364 and U-SIG 366 may indicate to EHT- or later version-compliant STAs 104 that the PPDU 350 is an EHT PPDU or a PPDU conforming to any later (post-EHT) version of a new wireless communication protocol conforming to a future IEEE 802.11 wireless communication protocol standard. For example, U-SIG 366 may be used by a receiving device to interpret bits in one or more of EHT-SIG 368 or the data field 374.
Access to the shared wireless medium is generally governed by a distributed coordination function (DCF). With a DCF, there is generally no centralized master device allocating time and frequency resources of the shared wireless medium. On the contrary, before a wireless communication device, such as an AP 102 or a STA 104, is permitted to transmit data, it must wait for a particular time and then contend for access to the wireless medium. In some aspects, the wireless communication device may be configured to implement the DCF through the use of carrier sense multiple access (CSMA) with collision avoidance (CA) (CSMA/CA) techniques and timing intervals. Before transmitting data, the wireless communication device may perform a clear channel assessment (CCA) and determine that the appropriate wireless channel is idle. The CCA includes both physical (PHY-level) carrier sensing and virtual (MAC-level) carrier sensing. Physical carrier sensing is accomplished via a measurement of the received signal strength of a valid frame, which is then compared to a threshold to determine whether the channel is busy. For example, if the received signal strength of a detected preamble is above a threshold, the medium is considered busy. Physical carrier sensing also includes energy detection. Energy detection involves measuring the total energy the wireless communication device receives regardless of whether the received signal represents a valid frame. If the total energy detected is above a threshold, the medium is considered busy. Virtual carrier sensing is accomplished via the use of a network allocation vector (NAV), an indicator of a time when the medium may next become idle. The NAV is reset each time a valid frame is received that is not addressed to the wireless communication device. The NAV effectively serves as a time duration that must elapse before the wireless communication device may contend for access even in the absence of a detected symbol or even if the detected energy is below the relevant threshold.
As described above, the DCF is implemented through the use of time intervals. These time intervals include the slot time (or “slot interval”) and the inter-frame space (IFS). The slot time is the basic unit of timing and may be determined based on one or more of a transmit-receive turnaround time, a channel sensing time, a propagation delay and a MAC processing time. Measurements for channel sensing are performed for each slot. All transmissions may begin at slot boundaries. Different varieties of IFS exist including the short IFS (SIFS), the distributed IFS (DIFS), the extended IFS (EIFS), and the arbitration IFS (AIFS). For example, the DIFS may be defined as the sum of the SIFS and two times the slot time. The values for the slot time and IFS may be provided by a suitable standard specification, such as one of the IEEE 802.11 family of wireless communication protocol standards (such as that defined by the IEEE 802.11-2016 specification or amendments thereof including, but not limited to, 802.11ay, 802.11ax, 802.11az, 802.11ba and 802.11be).
When the NAV reaches 0, the wireless communication device performs the physical carrier sensing. If the channel remains idle for the appropriate IFS (for example, the DIFS), the wireless communication device initiates a backoff timer, which represents a duration of time that the device must sense the medium to be idle before it is permitted to transmit. The backoff timer is decremented by one slot each time the medium is sensed to be idle during a corresponding slot interval. If the channel remains idle until the backoff timer expires, the wireless communication device becomes the holder (or “owner”) of a transmit opportunity (TXOP) and may begin transmitting. The TXOP is the duration of time the wireless communication device can transmit frames over the channel after it has won contention for the wireless medium. If, on the other hand, one or more of the carrier sense mechanisms indicate that the channel is busy, a MAC controller within the wireless communication device will not permit transmission.
Each time the wireless communication devices generates a new PPDU for transmission in a new TXOP, it randomly selects a new backoff timer duration. The available distribution of the numbers that may be randomly selected for the backoff timer is referred to as the contention window (CW). If, when the backoff timer expires, the wireless communication device transmits the PPDU, but the medium is still busy, there may be a collision. If there is otherwise too much energy on the wireless channel resulting in a poor signal-to-noise ratio (SNR), the communication may be corrupted or otherwise not successfully received. In such instances, the wireless communication device may not receive a communication acknowledging the transmitted PDU within a timeout interval. The MAC may then increase the CW exponentially, for example, doubling it, and randomly select a new backoff timer duration from the CW before each attempted retransmission of the PPDU. Before each attempted retransmission, the wireless communication device may wait a duration of DIFS and, if the medium remains idle, then proceed to initiate the new backoff timer. There are different CW and TXOP durations for each of the four access categories (ACs): voice (AC_VO), video (AC_VI), background (AC_BK), and best effort (AC_BE). The different durations and access categories enable particular types of traffic to be prioritized in the network.
Some APs and STAs may be configured to implement spatial reuse techniques. For example, APs and STAs configured for communications using IEEE 802.11ax or 802.11be may be configured with a BSS color. APs associated with different BSSs may be associated with different BSS colors. If an AP or a STA detects a wireless packet from another wireless communication device while contending for access, the AP or STA may apply different contention parameters based on whether the wireless packet is transmitted by, or transmitted to, another wireless communication device within its BSS or from a wireless communication device from an overlapping BSS (OBSS), as determined by a BSS color indication in a preamble of the wireless packet. For example, if the BSS color associated with the wireless packet is the same as the BSS color of the AP or STA, the AP or STA may use a first received signal strength indication (RSSI) detection threshold when performing a CCA on the wireless channel. However, if the BSS color associated with the wireless packet is different than the BSS color of the AP or STA, the AP or STA may use a second RSSI detection threshold in lieu of using the first RSSI detection threshold when performing the CCA on the wireless channel, the second RSSI detection threshold being greater than the first RSSI detection threshold. In this way, the requirements for winning contention are relaxed when interfering transmissions are associated with an OBSS.
The wireless communication device 400 can be, or can include, a chip, system on chip (SoC), chipset, package or device that includes one or more modems 402, for example, a Wi-Fi (IEEE 802.11 compliant) modem. In some aspects, the one or more modems 402 (collectively “the modem 402”) additionally include a WWAN modem (for example, a 3GPP 4G LTE or 5G compliant modem). In some aspects, the wireless communication device 400 also includes one or more processors, processing blocks or processors 404 (collectively “the processor 404”) coupled with the modem 402. In some aspects, the wireless communication device 400 additionally includes one or more radios 406 (collectively “the radio 406”) coupled with the modem 402. In some aspects, the wireless communication device 400 further includes one or more memory blocks or elements (collectively “the memory 408”) coupled with the processor 404 or the modem 402.
The modem 402 can include an intelligent hardware block or device such as, for example, an application-specific integrated circuit (ASIC), among other examples. The modem 402 is generally configured to implement a PHY layer, and in some implementations, also a portion of a MAC layer (for example, a hardware portion of the MAC layer). For example, the modem 402 is configured to modulate packets and to output the modulated packets to the radio 406 for transmission over the wireless medium. The modem 402 is similarly configured to obtain modulated packets received by the radio 406 and to demodulate the packets to provide demodulated packets. In addition to a modulator and a demodulator, the modem 402 may further include digital signal processing (DSP) circuitry, automatic gain control (AGC) circuitry, a coder, a decoder, a multiplexer and a demultiplexer. For example, while in a transmission mode, data obtained from the processor 404 may be provided to an encoder, which encodes the data to provide coded bits. The coded bits may then be mapped to a number NSS of spatial streams for spatial multiplexing or a number NSTS of space-time streams for space-time block coding (STBC). The coded bits in the streams may then be mapped to points in a modulation constellation (using a selected MCS) to provide modulated symbols. The modulated symbols in the respective spatial or space-time streams may be multiplexed, transformed via an inverse fast Fourier transform (IFFT) block, and subsequently provided to the DSP circuitry (for example, for Tx windowing and filtering). The digital signals may then be provided to a digital-to-analog converter (DAC). The resultant analog signals may then be provided to a frequency upconverter, and ultimately, the radio 406. In implementations involving beamforming, the modulated symbols in the respective spatial streams are precoded via a steering matrix prior to their provision to the IFFT block.
While in a reception mode, the DSP circuitry is configured to acquire a signal including modulated symbols received from the radio 406, for example, by detecting the presence of the signal and estimating the initial timing and frequency offsets. The DSP circuitry is further configured to digitally condition the signal, for example, using channel (narrowband) filtering and analog impairment conditioning (such as correcting for I/Q imbalance), and by applying digital gain to ultimately obtain a narrowband signal. The output of the DSP circuitry may then be fed to the AGC, which is configured to use information extracted from the digital signals, for example, in one or more received training fields, to determine an appropriate gain. The output of the DSP circuitry also is coupled with a demultiplexer that demultiplexes the modulated symbols when multiple spatial streams or space-time streams are received. The demultiplexed symbols may be provided to a demodulator, which is configured to extract the symbols from the signal and, for example, compute the logarithm likelihood ratios (LLRs) for each bit position of each subcarrier in each spatial stream. The demodulator is coupled with the decoder, which may be configured to process the LLRs to provide decoded bits. The decoded bits may then be descrambled and provided to the MAC layer (the processor 404) for processing, evaluation or interpretation.
The radio 406 generally includes at least one radio frequency (RF) transmitter (or “transmitter chain”) and at least one RF receiver (or “receiver chain”), which may be combined into one or more transceivers. For example, each of the RF transmitters and receivers may include various analog circuitry including at least one power amplifier (PA) and at least one low-noise amplifier (LNA), respectively. The RF transmitters and receivers may, in turn, be coupled to one or more antennas. For example, in some aspects, the wireless communication device 400 can include, or be coupled with, multiple transmit antennas (each with a corresponding transmit chain) and multiple receive antennas (each with a corresponding receive chain). The symbols output from the modem 402 are provided to the radio 406, which then transmits the symbols via the coupled antennas. Similarly, symbols received via the antennas are obtained by the radio 406, which then provides the symbols to the modem 402.
The processor 404 can include an intelligent hardware block or device such as, for example, a processing core, a processing block, a central processing unit (CPU), a microprocessor, a microcontroller, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a programmable logic device (PLD) such as a field programmable gate array (FPGA), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. The processor 404 processes information received through the radio 406 and the modem 402, and processes information to be output through the modem 402 and the radio 406 for transmission through the wireless medium. For example, the processor 404 may implement a control plane and at least a portion of a MAC layer configured to perform various operations related to the generation, transmission, reception and processing of MPDUs, frames or packets. In some aspects, the MAC layer is configured to generate MPDUs for provision to the PHY layer for coding, and to receive decoded information bits from the PHY layer for processing as MPDUs. The MAC layer may further be configured to allocate time and frequency resources, for example, for OFDMA, among other operations or techniques. In some aspects, the processor 404 may generally control the modem 402 to cause the modem (e.g., in conjunction with at least one processor) to perform various operations described above.
The memory 408 can include tangible storage media such as random-access memory (RAM) or read-only memory (ROM), or combinations thereof. The memory 408 also can store non-transitory processor- or computer-executable software (SW) code containing instructions that, when executed by the processor 404, cause the processor to perform various operations described herein for wireless communication, including the generation, transmission, reception and interpretation of MPDUs, frames or packets. For example, various functions of components disclosed herein, or various blocks or steps of a method, operation, process or algorithm disclosed herein, can be implemented as one or more modules of one or more computer programs.
Transmitting on such mutually orthogonally fixed antennas generates signals with different polarization, which prevents the signals (e.g., from MIMO or beamforming) from combining near the AP 602 (as a transmitting device). In indoor environments, however, where PSD considerations described above are the most sever, the polarized signals will scatter off of the indoor surfaces, causing the polarized signals to lose their polarization (e.g., the directional nature resulting from the mutually orthogonal fixed orientations 610, 620, and 630). When a receiver then receives the signals after the signals scatter off of surfaces in the environment, the receiver can combine the signals to achieve the performance gains described above, without the drawback of reduced transmission power associated with antenna array transmission of correlated signals.
As described above, in some aspects, HALPHY 754 can use static parameters that are fixed for multiple sets of data. HALPHY 754 can dynamically compute revised transmission parameters on a per-packet basis (e.g., depending on specific characteristics associated with a data packet). The revised transmission parameters and selected polarization masks are passed from HALPHY 754 to firmware link controller 752. The firmware link controller then sends a data packet with the revised transmission parameters for the data packet and polarization diversity signaling information to MAC 720. MAC 720 uses the provided information to generate encapsulated packets that are provided to the PHY 710. The PHY 710 receives both the encapsulated packets from MAC 720 and configuration settings from HALPHY 754 (e.g., revised using the static parameters and dynamic parameters). The PHY 710 can use this data to generate signals for transmission via antennas 790, along with polarization diversity controls that are used in transmitting the signals. Additional details related to such controls and signaling are described below.
In some implementations, in block 802, the wireless communication device can be configured with orthogonally fixed antennas for polarization diversity. The wireless communication device can perform one or more operations to set transmission configuration settings for the wireless communication device. In some aspects, a control table of the wireless communication device (e.g., an AP or STA) can include power selection operations for multiple different device configurations. In such aspects, the wireless communication device can be configured with a particular setting to use a fixed set of data from the control table, and the wireless communication device will use an assigned subset of data from the control table during operation based on the configuration settings. The configuration can indicate transmission groupings of antennas which include or lack polarization diversity within an antenna grouping. The configuration can, for example, indicate the fixed polarization groupings of antennas for a device. For example, a control table can include settings for orthogonal antenna groups of 8 antennas as {6,1,1} {4,2,2} {3,3,2}, or any other such option. Configuration settings can be used to indicate which actual physical antenna configuration is present in a device, and to limit the device to using the appropriate settings for polarization diversity (e.g., orientations) among the antennas present in a given device.
In some implementations, in block 804, the wireless communication device can determine whether polarization diversity is enabled. For instance, when the wireless communication device is performing communication operations, if polarization diversity is not enabled by device configuration settings, in block 822, the wireless communication device can perform operations independent of polarization diversity operations (e.g., independent gain settings) in accordance with aspects described herein.
If, at block 804, the wireless communication device determines that polarization diversity is enabled, then for a given transmission configuration, the wireless communication device can compute an array gain in each polarization plane at block 806. In some implementations, in block 808, the wireless communication device can compute the transmission power for each antenna using the array gain for the corresponding polarization plane. In some aspects, the operations will result in all antennas having the same transmit power. In other aspects, such as when certain polarization planes (e.g., fixed orientations) are used to transmit correlated signals and other polarization planes are not, the per antenna transmission power set by a wireless communication device can vary greatly.
In one example of a 4-antenna device, three polarization planes (e.g., fixed orientations) are present: Hx, Hy, and Vz, with Vz having two antennas, and the other planes each having one antenna. For improved power transmission, the two antennas Vz1 and Vz2 need to carry separate uncorrelated signals. If correlated signals are carried on these two antennas, a power backoff is needed to meet power thresholds as described above. The Hx and Hy planes can carry correlated data, since the signals transmitted on the orthogonal polarization planes will be uncorrelated even though the data in the signals can be correlated. In some aspects, a wireless communication device can be configured to only transmit on three antennas when uncorrelated data is not available to allow Vz1 and Vz2 to transmit with uncorrelated data. In other aspects, a space-time block code (STBC) can be used by a wireless communication device to create streams for Vz1 and Vz2,
In some aspects, a wireless communication device can perform beamforming by using correlated signals at an antenna array, such as in environments with available scattering surfaces. Correlated signals in beamforming are likely to cause constructive interference at random points in space, resulting in a need to reduce the power to individual antenna elements by a back off amount to meet power restriction thresholds. As detailed above, radiating beamforming signals in independent polarization planes results in uncorrelated signals from the transmitting device prior to the signals scattering. Correlation between signals in different polarization planes is represented by a metric referred to as cross-polarization discrimination. Prior to scattering, polarization diversity from orthogonal antennas results in large cross polarization discrimination (e.g., greater than 20 decibels (dB)). After repeated reflections (e.g., due to an indoor environment with many surfaces for scattering), signals are attenuated, and both co-polarized and cross-polarized (e.g., from orthogonal antennas) have similar received signal strength indication (RSSI) distributions at receiver antennae. Further, the cross-polarization discrimination described above becomes diminishingly small (e.g., reduces from 20 dB to 0 dB), matching the cross-polarization discrimination from co-polarized transmissions (e.g., transmitted from antennas in the same orientation). Reflections (e.g., scattered signals) from objects in an environment can thus be constructively combined at a receiver with sufficient reflective surfaces. By using cross-polarized but correlated signals, unwanted constructive interference can be avoided near a transmitter, but desired constructive interference can be achieved at a receiving device. The receiving and transmitting device in such aspects can function using standard sounding and steering operations. Such a use of cross-polarized antennas can thus enable higher transmission power at a transmitting device, and improved performance and reception of signals at a receiving device in an environment with sufficient scattering, using standard beamforming operations to control the signal from the transmitting device to the receiving device.
In some aspects, a wireless communication device configured for cross-polarization operation can be used in a PSD restricted environment as follows:
If disabled (e.g., if the AP does not support Polarization Diversity), the control (e.g., CTL) tables will be used as per the Ntx assignment rules below,
If enabled (If the AP supports Polarization Diversity), the CTL tables will be used as per the Ntx assignment rules below,
For Data packets,
Table 1 below specifies the Tx Power the transmitter is capable of generating based on various criteria, such as EVM, spectral masks, etc., for various types of transmission (e.g., modulation and coding scheme (MCS), BW, single user/multiuser (SU/MU), etc.). Table 1 illustrates the performance of transmissions by a wireless communication device in mid-range performance in accordance with some aspects. Certain transmissions are limited by control table power limits. For 4×1 and 4×2 operations, per antenna transmit power is limited to between 11.5 and 14.5 dBm without polarization diversity as described herein. With polarization diversity, a gain of 3 dB is seen, and other power limits increase as well.
——SU——
——MU——
——SU——
——MU——
——SU——
——MU——
——SU——
——MU——
TABLE 2 illustrates an example CTL control table in accordance with some aspects, with data indicating whether polarization diversity is enabled, whether beamforming is enabled (BF), the number of antennas (Ntx), the number of communication streams (Nas), and the channels with associated frequencies and channel bandwidths.
In table 2, the table values other than the diversity flag (e.g., indicating the polarization diversity status) and beamforming flag (e.g., indicating a beamforming use status), and the Ntx and Nss indicators, are power targets per transmission chain. When the polarization diversity value is 0, the array gain will be (10*log 10(Ntx/Nss)). When the polarization diversity value is 1, the array gain will be 0.
In some aspects, a wireless communication device can operate where the static values from a CTL control table such as table 2 can be combined with dynamic data stream (e.g., per-packet) array gain contributions determined in software at a physical (e.g., HALPHY) layer of a device. In some such aspects, an array gain for a wireless communication device can be determined as follows:
Array Gain is distributed between the static (CTL Table) and the dynamic (computed per-packet) contributions as:
The CTL table provides the target power conforming to the regulatory guidelines using Gstatic for a reference antenna configuration. The physical layer computes the GDyn for the actual antenna configuration used, such that Gdyn>=1 (e.g., avoiding accidental violations).
Inputs used for CTL Table generation are the table values described above for a polarization mode and the antenna and communication settings (e.g. Ntx and Nss) along with the channel details.
Cmax represents a maximum (max) modified number of Co-polarized Antenna. Cmax can be determined as per one or more of the following approaches:
In some aspects, a single table works for a given polarization Number (e.g., 3 with three orthogonal directions) and given antenna plane configurations (e.g., for 8 antennas: configurations, viz., 3-3-2, 4-3-1, 4-2-2, 5-2-1, 6-1-1).
Similarly, a separate table works for Polarization Number-2 (e.g., for 8 antennas: configurations, viz., 4-4, 5-3, 6-2, 7-1).
In some aspects:
In some aspects:
C_max=max(N_(Tx,X),N_(Tx,Y),N_(Tx,Z))
Where Cmax=maximum number of co-polarized antenna in the antenna configuration used. A table can be used based on the number of polarization planes present in a device as described above. In some such aspects, a 3-3-2 division of antennas amount the polarization planes is optimal for γ=3 and a 4-4 division of antennas among the polarization planes is optimal for γ=2.
For the examples above, an array Gain used in the CTL table is then:
Examples of 8 antennas are described above, but in additional aspects, other configurations or different numbers of antennas can be used by a wireless communication device. Table 3 illustrates details of the possible configurations for a device with 8 antennas, with mask-based configurations illustrated in the table. In some aspects, such masks can be signaled in a data packet and used for data signaling with polarization diversity and in some aspects the masks can be used by the MAC to signal to the PHY about the specified antenna to be used for a particular packet.
For beamforming, additional inputs can be used in computation of an array gain penalty. In some aspects, the inputs used to determine gain penalties in a wireless communication device are the same inputs described above, with the additional polarization mask inputs indicating a specific antenna configuration used on the device for each polarization plane, along with a maximum number of copolarized antenna related to the polarization masks.
In some aspects:
In some aspects:
In some aspects:
C max=max(bitsum(Xm),bitsum(Ym),bitsum(Zm))
The physical layer can then use the following as inputs to compute the Array Gain Penalty: a Tx Chain Mask (Cm) is determined in firmware for every packet according to the mask as associated with the antenna selection pattern; the control table; and the antenna planes.
A total number of Co-polarized antenna per packet (Amax) is then calculated as:
A max=Max(Bitsum(Xm AND Cm),Bitsum(Ym AND Cm),Bitsum(Zm AND Cm))
The array gain penalty as calculated in firmware is then determined as;
Tables 4-9 illustrate additional aspects of possible antenna configurations with associated masks that can be used in configuration polarization diversity communications in accordance with aspects described herein.
For aspects of wireless communication device performance, including beamforming, a polarization plane can be assigned to individual elements of a selected antenna array configuration. Polarization diversity and masks or maps can be added to configuration tables, with control table limits updated based on the particular antenna array configurations. In such aspects, firmware of a wireless communication device can read the table fields and implement operations to determine appropriate Ntx and mask selection. Additional firmware operations can select co-planar or cross-polarized antenna assignments. Such assignments can be fixed or dynamic for a given wireless communication device. The firmware can then further implement a polarization configuration specific probing sequence to assess scattering patterns and manage control of a beam. The wireless communication device can then perform scheduling of beamforming based transmissions based on the specific system configurations.
When smart antenna configurations are combined with MIMO, additional configuration elements can be used. In some aspects, a wireless communication device can operate with a simple antenna selection scheme for smart antenna MIMO configurations can be used in accordance with aspects described above. In some aspects, each polarization plane is selectably configured for cross-polarized transmissions using all available polarization planes per transmission chain. In some aspects, the wireless communication device can configure each transmit chain for use with sectorized polarization domains. The wireless communication device can use generalized optimization with both cross-polarization and simple antenna assignments for different transmit chains. Such aspects can support plane diversity as well as pattern diversity with beamforming and MIMO operations. In some aspects, MIMO implementations in wireless communication devices include a number of antennas equal to the number of transmit and receive chains, so a dedicated antenna (e.g., with an associated polarization) is associated with each chain. In some aspects, smart antennas function as a superset of MIMO operations with antenna arrays (e.g., a set of antennas or antenna elements that can be used for beamforming). Smart antennas may have a number of antennas much larger than the number of transmit or receive chains. In aspects where smart antenna systems support MIMO, a system can configure antenna elements from the available antenna elements for every transmission or receive chain.
In some aspects, a wireless communication device can include M elements and one housing per transmit chain, with the number of combination options L=M×Ntx. If multiple sectors can be excited per housing, then the number of combinations becomes L=Ntx{circumflex over ( )}(2{circumflex over ( )}M). With such a large number of transmit chain-to-sector mappings, the wireless communication device can use simple rules to select a mapping, such as using identical sectors for each housing.
In some aspects, such as indoor environments with significant scattering, antenna housings of the wireless communication device can be divided into a maximum number of supported polarization planes. For example, with four transmit chains, one housing can be assigned per polarization plane. With eight transmit chains, two antenna housings can be assigned per polarization plane.
Illustrative examples of four antenna implementations include:
Where the array gain penalty is 0 dB for Nss values 1, 2, or 4, 1.2 dB for Nss values of 3, and effectively 6 dB of power gain is present for Nss of 1 with a net mean gain range between 3 and 5 dBm.
Illustrative examples of eight antenna configurations include:
In some aspects, smart antenna systems of a wireless communication device can dynamically select antenna assignments to polarization planes for any transmission chain. In some such aspects, a smart antenna selection algorithm synthesizes polarization masks dynamically, and selects the polarization masks for given packets. In such aspects, the control table values (e.g., similar to table 2 above) can be static or dynamically determined based on the synthesized polarization masks. Such systems can then compute Cmax, the dynamic chain mask, Amax, and the array gain penalty as described for the examples above.
In some implementations, in block 902, the wireless communication device (e.g., the polarization diversity transmission setting engine 912 of the wireless communication device 910) can determine first transmission power levels for a first set of one or more antennas and second transmission power levels for a second set of one or more antennas based on a polarization diversity setting for a wireless communication device. For example, the polarization diversity setting being based on a first orientation of the first set of one or more antennas being orthogonal to a second orientation of the second set of one or more antennas.
In some implementations, in block 904, the wireless communication device can transmit, to a target device, first signals at the first transmission power levels using the first set of one or more antennas (the first set of one or more antennas 920).
In some implementations, in block 906, the wireless communication device can transmit, to the target device, second signals at the second transmission power levels using the second set of one or more antennas (the first set of one or more antennas 920). The first signals are cross-polarized from the second signals based on the first orientation being orthogonal to the second orientation.
In some aspects, the wireless communication device can determine the polarization diversity setting for one or more communications, the polarization diversity setting indicating that the first signals and the second signals are cross-polarized signals. The wireless communication device can determine antenna assignments for one or more communications at least in part by assigning the first set of one or more antennas and the second set of one or more antennas to the one or more communications. In some aspects, wireless communication device can determine the antenna assignments based on polarization masks configured for a data packet. In some aspects, wireless communication device can determine the antenna assignments based on frame types for the one or more communications. The wireless communication device can further select the first transmission power levels for the first set of one or more antennas and the second transmission power levels for the second set of one or more antennas based on the polarization diversity setting and the antenna assignments.
In some aspects, the wireless communication device can determine a first array gain for the first set of one or more antennas based on the antenna assignments. The wireless communication device can determine a second array gain for the second set of one or more antennas based on the antenna assignments. The wireless communication device can further determine determining a transmission power level for each antenna of the first set of one or more antennas based on the first array gain and for each antenna of the second set of one or more antennas based in the second array gain.
In some aspects, the wireless communication device can compute at least one of the first array gain for the first set of one or more antennas and the second array gain for the second set of one or more antennas using data from a control table associated with the antenna assignments and channels associated with the one or more communications and the antenna assignments. In some examples, the data from the control table includes one or more static values for a configuration of the wireless communication device.
In some aspects, the wireless communication device can compute at least one of the first array gain for the first set of one or more antennas and the second array gain for the second set of one or more antennas using one or more dynamic values from one or more settings for the one or more communications.
In some aspects, a first communication of the one or more communications is assigned to a first antenna of the first set of one or more antennas and a first antenna of the second set of one or more antennas. The wireless communication device can calculate or compute a transmit power for the first antenna of the first set of one or more antennas and the first antenna of the second set of one or more antennas based on a polarization diversity between the first antenna of the first set of one or more antennas and the first antenna of the second set of one or more antennas.
In some aspects, a first communication of the one or more communications is assigned to a first antenna of the first set of one or more antennas and a second antenna of the first set of one or more antennas. The wireless communication device can calculate or compute a transmit power for the first antenna of the first set of one or more antennas and the second antenna of the first set of one or more antennas with a power reduction based on a correlation between signals on the first antenna and the second antenna and a lack of polarization diversity between the first antenna of the first set of one or more antennas and the second antenna of the first set of one or more antennas.
In some aspects, a first communication of the one or more communications is assigned to at least two antennas of the first set of one or more antennas and at least two antennas of the second set of one or more antennas. The wireless communication device can determine a transmit power for each antenna assigned to the first communication based on an associated array gain computed for antennas associated with the first orientation and an associated array gain computed for antennas associated with the second orientation.
In some aspects, the wireless communication device includes third one or more antennas fixed in a third orientation. In such aspects, the first orientation, the second orientation, and the third orientation are mutually orthogonal.
In some aspects, the wireless communication device can compute an array gain for each antenna based on a dynamic per-packet gain contribution determined using a physical layer of the wireless communication device and using a target power from a control table fixed for the wireless communication device based on a reference antenna configuration. For example, the wireless communication device can identify or determine the target power based on a number of the one or more communications, a number of orientations associated with the antenna assignments, a polarization diversity status, and a number of co-polarized antennas for each orientation of the number of orientations.
In one illustrative example, the wireless communication device includes eight antennas distributed among available orientations. In such an example, each of the one or more communications is assigned one antenna from each available orientation. An array gain penalty for each available orientation is 3 decibels (dB).
In some aspects, the wireless communication device can transmit cross-polarized steering and sounding beamforming signals using the first set of one or more antennas and the second set of one or more antennas, wherein the first signals and the second signals are beamformed transmissions based on the steering and sounding beamforming signals.
As used herein, “or” is used intended to be interpreted in the inclusive sense, unless otherwise explicitly indicated. For example, “a or b” may include a only, b only, or a combination of a and b. As used herein, a phrase referring to “at least one of” or “one or more of” a list of items refers to any combination of those items, including single members. For example, “at least one of: a, b, or c” is intended to cover the examples of: a only, b only, c only, a combination of a and b, a combination of a and c, a combination of b and c, and a combination of a and b and c.
The various illustrative components, logic, logical blocks, modules, circuits, operations and algorithm processes described in connection with the aspects disclosed herein may be implemented as electronic hardware, firmware, software, or combinations of hardware, firmware or software, including the structures disclosed in this specification and the structural equivalents thereof. The interchangeability of hardware, firmware and software has been described generally, in terms of functionality, and illustrated in the various illustrative components, blocks, modules, circuits and processes described above. Whether such functionality is implemented in hardware, firmware or software depends upon the particular application and design constraints imposed on the overall system.
Various modifications to the aspects described in this disclosure may be readily apparent to persons having ordinary skill in the art, and the generic principles defined herein may be applied to other aspects without departing from the spirit or scope of this disclosure. Thus, the claims are not intended to be limited to the aspects shown herein, but are to be accorded the widest scope consistent with this disclosure, the principles and the novel features disclosed herein.
Various features that are described in this specification in the context of separate aspects also can be implemented in combination in a single aspect. Conversely, various features that are described in the context of a single aspect also can be implemented in multiple aspects separately or in any suitable subcombination. As such, although features may be described above as acting in particular combinations, and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.
Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. Further, the drawings may schematically depict one or more example processes in the form of a flowchart or flow diagram. However, other operations that are not depicted can be incorporated in the example processes that are schematically illustrated. For example, one or more additional operations can be performed before, after, simultaneously, or between any of the illustrated operations. In some circumstances, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the aspects described above should not be understood as requiring such separation in all aspects, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products.
Illustrative aspects of the present disclosure include:
Aspect 1: A wireless communication device, comprising: at least one modem; a first set of one or more antennas communicatively coupled to the at least one modem and having a first orientation; a second set of one or more antennas communicatively coupled to the at least one modem and having a second orientation that is orthogonal to the first orientation; at least one processor communicatively coupled with the at least one modem; and at least one memory communicatively coupled with the at least one processor and storing processor-readable code that, when executed by the at least one processor in conjunction with the at least one modem, is configured to: determine first transmission power levels for the first set of one or more antennas and second transmission power levels for the second set of one or more antennas based on a polarization diversity setting for the wireless communication device, the polarization diversity setting being based on the first orientation of the first set of one or more antennas being orthogonal to the second orientation of the second set of one or more antennas; transmit, to a target device, first signals at the first transmission power levels using the first set of one or more antennas; and transmit, to the target device, second signals at the second transmission power levels using the second set of one or more antennas, the first signals being cross-polarized from the second signals based on the first orientation being orthogonal to the second orientation.
Aspect 2: The wireless communication device of Aspect 1, wherein the processor-readable code, when executed by the at least one processor in conjunction with the at least one modem, is further configured to: determine the polarization diversity setting for one or more communications, the polarization diversity setting indicating that the first signals and the second signals are cross-polarized signals; determine antenna assignments for one or more communications at least in part by assigning the first set of one or more antennas and the second set of one or more antennas to the one or more communications; and select the first transmission power levels for the first set of one or more antennas and the second transmission power levels for the second set of one or more antennas based on the polarization diversity setting and the antenna assignments.
Aspect 3: The wireless communication device of Aspect 2, wherein the processor-readable code, when executed by the at least one processor in conjunction with the at least one modem, is further configured to: determine a first array gain for the first set of one or more antennas based on the antenna assignments; determine a second array gain for the second set of one or more antennas based on the antenna assignments; and determine a transmission power level for each antenna of the first set of one or more antennas based on the first array gain and for each antenna of the second set of one or more antennas based in the second array gain.
Aspect 4: The wireless communication device of Aspect 3, wherein the processor-readable code, when executed by the at least one processor in conjunction with the at least one modem, is further configured to: compute at least one of the first array gain for the first set of one or more antennas and the second array gain for the second set of one or more antennas using data from a control table associated with the antenna assignments and channels associated with the one or more communications and the antenna assignments.
Aspect 5: The wireless communication device of Aspect 4, wherein the data from the control table includes one or more static values for a configuration of the wireless communication device.
Aspect 6: The wireless communication device of any of Aspects 3 to 5, wherein the processor-readable code, when executed by the at least one processor in conjunction with the at least one modem, is further configured to: compute at least one of the first array gain for the first set of one or more antennas and the second array gain for the second set of one or more antennas using one or more dynamic values from one or more settings for the one or more communications.
Aspect 7: The wireless communication device of any of Aspects 1 to 6, wherein a first communication of the one or more communications is assigned to a first antenna of the first set of one or more antennas and a first antenna of the second set of one or more antennas, and wherein a transmit power for the first antenna of the first set of one or more antennas and the first antenna of the second set of one or more antennas is calculated based on a polarization diversity between the first antenna of the first set of one or more antennas and the first antenna of the second set of one or more antennas.
Aspect 8: The wireless communication device of any of Aspects 1 to 6, wherein a first communication of the one or more communications is assigned to a first antenna of the first set of one or more antennas and a second antenna of the first set of one or more antennas.
Aspect 9: The wireless communication device of Aspect 8, wherein a transmit power for the first antenna of the first set of one or more antennas and the second antenna of the first set of one or more antennas is calculated with a power reduction based on a correlation between signals on the first antenna and the second antenna and a lack of polarization diversity between the first antenna of the first set of one or more antennas and the second antenna of the first set of one or more antennas.
Aspect 10: The wireless communication device of Aspect 1 to 6, wherein a first communication of the one or more communications is assigned to at least two antennas of the first set of one or more antennas and at least two antennas of the second set of one or more antennas.
Aspect 11: The wireless communication device of Aspect 10, wherein transmit power for each antenna assigned to the first communication is determined based on an associated array gain computed for antennas associated with the first orientation and an associated array gain computed for antennas associated with the second orientation.
Aspect 12: The wireless communication device of any of Aspects 1 to 11, further comprising: third one or more antennas fixed in a third orientation and communicatively coupled to the at least one modem, wherein the first orientation, the second orientation, and the third orientation are mutually orthogonal.
Aspect 13: The wireless communication device of any of Aspects 2 to 12, wherein the processor-readable code, when executed by the at least one processor in conjunction with the at least one modem, is further configured to: compute an array gain for each antenna based on a dynamic per-packet gain contribution determined using a physical layer of the wireless communication device and using a target power from a control table fixed for the wireless communication device based on a reference antenna configuration, the target power identified based on a number of the one or more communications, a number of orientations associated with the antenna assignments, a polarization diversity status, and a number of co-polarized antennas for each orientation of the number of orientations.
Aspect 14: The wireless communication device of any of Aspects 1 to 13, wherein the wireless communication device includes eight antennas distributed among available orientations, wherein each of the one or more communications is assigned one antenna from each available orientation, and wherein an array gain penalty for each available orientation is 3 decibels (dB).
Aspect 15: The wireless communication device of any of Aspects 2 to 14, wherein the antenna assignments are determined based on polarization masks configured for a data packet.
Aspect 16: The wireless communication device of any of Aspects 2 to 15, wherein the antenna assignments based on frame types for the one or more communications.
Aspect 17: The wireless communication device of any of Aspects 1 to 16, wherein the processor-readable code, when executed by the at least one processor in conjunction with the at least one modem, is further configured to: transmit cross-polarized steering and sounding beamforming signals using the first set of one or more antennas and the second set of one or more antennas, wherein the first signals and the second signals are beamformed transmissions based on the steering and sounding beamforming signals.
Aspect 18: A method for wireless communication transmission, the method comprising: determining first transmission power levels for a first set of one or more antennas and second transmission power levels for a second set of one or more antennas based on a polarization diversity setting for a wireless communication device, the polarization diversity setting being based on a first orientation of the first set of one or more antennas being orthogonal to a second orientation of the second set of one or more antennas; transmitting, to a target device, first signals at the first transmission power levels using the first set of one or more antennas; and transmitting, to the target device, second signals at the second transmission power levels using the second set of one or more antennas, the first signals being cross-polarized from the second signals based on the first orientation being orthogonal to the second orientation.
Aspect 19: The method of Aspect 18, further comprising: determining the polarization diversity setting for one or more communications, the polarization diversity setting indicating that the first signals and the second signals are cross-polarized signals; determining antenna assignments for one or more communications at least in part by assigning the first set of one or more antennas and the second set of one or more antennas to the one or more communications; and selecting the first transmission power levels for the first set of one or more antennas and the second transmission power levels for the second set of one or more antennas based on the polarization diversity setting and the antenna assignments.
Aspect 20: The method of Aspect 19, further comprising: determining a first array gain for the first set of one or more antennas based on the antenna assignments; determining a second array gain for the second set of one or more antennas based on the antenna assignments; and determining a transmission power level for each antenna of the first set of one or more antennas based on the first array gain and for each antenna of the second set of one or more antennas based in the second array gain.
Aspect 21: The method of Aspect 20, further comprising: computing at least one of the first array gain for the first set of one or more antennas and the second array gain for the second set of one or more antennas using data from a control table associated with the antenna assignments and channels associated with the one or more communications and the antenna assignments.
Aspect 22: The method of Aspect 21, wherein the data from the control table includes one or more static values for a configuration of the wireless communication device.
Aspect 23: The method of any of Aspects 20 to 22, further comprising: computing at least one of the first array gain for the first set of one or more antennas and the second array gain for the second set of one or more antennas using one or more dynamic values from one or more settings for the one or more communications.
Aspect 24: The method of any of Aspects 18 to 23, wherein a first communication of the one or more communications is assigned to a first antenna of the first set of one or more antennas and a first antenna of the second set of one or more antennas, and wherein a transmit power for the first antenna of the first set of one or more antennas and the first antenna of the second set of one or more antennas is calculated based on a polarization diversity between the first antenna of the first set of one or more antennas and the first antenna of the second set of one or more antennas.
Aspect 25: The method of any of Aspects 18 to 23, wherein a first communication of the one or more communications is assigned to a first antenna of the first set of one or more antennas and a second antenna of the first set of one or more antennas.
Aspect 26: The method of Aspect 25, wherein a transmit power for the first antenna of the first set of one or more antennas and the second antenna of the first set of one or more antennas is calculated with a power reduction based on a correlation between signals on the first antenna and the second antenna and a lack of polarization diversity between the first antenna of the first set of one or more antennas and the second antenna of the first set of one or more antennas.
Aspect 27: The method of any of Aspects 18 to 23, wherein a first communication of the one or more communications is assigned to at least two antennas of the first set of one or more antennas and at least two antennas of the second set of one or more antennas.
Aspect 28: The method of Aspect 27, wherein transmit power for each antenna assigned to the first communication is determined based on an associated array gain computed for antennas associated with the first orientation and an associated array gain computed for antennas associated with the second orientation.
Aspect 29: The method of any of Aspects 18 to 28, wherein the wireless communication device includes third one or more antennas fixed in a third orientation, wherein the first orientation, the second orientation, and the third orientation are mutually orthogonal.
Aspect 30: The method of any of Aspects 19 to 29, further comprising: computing an array gain for each antenna based on a dynamic per-packet gain contribution determined using a physical layer of the wireless communication device and using a target power from a control table fixed for the wireless communication device based on a reference antenna configuration, the target power identified based on a number of the one or more communications, a number of orientations associated with the antenna assignments, a polarization diversity status, and a number of co-polarized antennas for each orientation of the number of orientations.
Aspect 31: The method of any of Aspects 18 to 30, wherein the wireless communication device includes eight antennas distributed among available orientations, wherein each of the one or more communications is assigned one antenna from each available orientation, and wherein an array gain penalty for each available orientation is 3 decibels (dB).
Aspect 32: The method of any of Aspects 19 to 31, wherein the antenna assignments are determined based on polarization masks configured for a data packet.
Aspect 33: The method of any of Aspects 19 to 32, wherein the antenna assignments based on frame types for the one or more communications.
Aspect 34: The method of any of Aspects 18 to 33, further comprising: transmitting cross-polarized steering and sounding beamforming signals using the first set of one or more antennas and the second set of one or more antennas, wherein the first signals and the second signals are beamformed transmissions based on the steering and sounding beamforming signals.
Aspect 35. A computer-readable storage medium storing instructions that, when executed by one or more processors, cause the one or more processors to perform operations according to any of Aspects 1 to 34.
Aspect 36. An apparatus comprising means for performing operations according to any of Aspects 1 to 34.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202121038574 | Aug 2021 | IN | national |
This application for Patent is a 371 application of international Patent Application PCT/US2022/037496, filed Jul. 18, 2022, which claims priority to Indian Patent Application 202121038574, filed Aug. 25, 2021, which are hereby incorporated by referenced in their entirety and for all purposes.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2022/037496 | 7/18/2022 | WO |
