The present disclosure relates to a wireless communication, and in particular, to an apparatus for and method of uplink beamforming in a wireless local area network (WLAN) system.
As an example of wireless communication, a WLAN is a technique for connecting two or more devices by using a wireless signal transfer method. The WLAN technique may comply with the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard. The 802.11 standard has evolved into 802.11b, 802.11a, 802.11g, 802.11n, 802.11ac, 802.11ax, etc., and may support a transmission speed up to 1 Gbyte/s based on orthogonal frequency-division multiplexing (OFDM) technology.
According to the 802.11ac standard, data may be simultaneously transmitted to a plurality of users using a multi-user multi-input multi-output (MU-MIMO) method. In the 802.11 ax standard, referred to as high efficiency (HE), access to multiple users is implemented by dividing and providing users with available subcarriers by applying an orthogonal frequency-division multiple access (OFDMA) technology as well as MU-MIMO. As such, a WLAN system based on the 802.11ax standard may effectively support communication in a dense area and an outdoor area.
In the 802.11b standard, referred to as extremely high throughput (EHT), support for 6 GHz unlicensed frequency band, utilization of bandwidth of maximum 320 MHz for each channel, introduction of hybrid automatic repeat and request (HARQ), support of maximum 16×16 MIMO, etc. are to be implemented. As such, a next generation WLAN system may effectively support low latency and ultra high-speed transmission such as new radio (NR) that is a 5G technique. However, next generation WLAN systems require a large amount of signaling and a large amount of resources to perform uplink beamforming. Accordingly, there is a need to reduce signaling and resources required to perform uplink beamforming.
Example embodiments of the present disclosure an apparatus for and method of effectively implementing uplink beamforming in a wireless local area network (WLAN) system.
According to an aspect of an example embodiment, an operating method of a first device communicating with a second device in a wireless local area network (WLAN), includes: receiving, from the second device, a physical layer protocol data unit (PPDU) including a payload that includes a trigger frame; preparing an uplink beamforming matrix based on a value of an uplink beamforming-related first sub-field included in a preamble of the PPDU; beamforming, according to the uplink beamforming matrix, the PPDU; and transmitting the beamformed PPDU to the second device based on a value of an uplink beamforming-related second sub-field included in the trigger frame.
According to an aspect of an example embodiment, an operating method of a first device communicating with a second device in a wireless local area network (WLAN), includes: receiving, from the second device, a null data packet announcement (NDPA) signal and a null data packet (NDP); preparing an uplink beamforming matrix based on the NDP; receiving a trigger frame including an uplink beamforming-related sub-field from the second device; beamforming an uplink signal according to the uplink beamforming matrix based on a value of the sub-field; and transmitting the beamformed uplink signal to the second device.
According to an aspect of an example embodiment, an operating method of a first device communicating with a second device in a wireless local area network (WLAN), includes: receiving, from the second device, an aggregated-media access control (MAC) protocol data unit (A-MPDU) including a first trigger frame corresponding to a first band; preparing an uplink beamforming matrix based on a value of an uplink beamforming-related first sub-field included in a preamble corresponding to the first band of the A-MPDU; beamforming, according to the uplink beamforming matrix, the A-MPDU; and transmitting the beamformed A-MPDU to the second device based on a value of an uplink beamforming-related second sub-field included in the first trigger frame.
According to an aspect of an example embodiment, a modem chip includes: a receiving beamforming circuit including a payload including a trigger frame, wherein the receiving beamforming circuit is configured to prepare an uplink beamforming matrix based on a value of an uplink beamforming-related first sub-field included in a preamble of a physical layer protocol data unit (PPDU) received from a radio frequency integrated circuit (RFIC); and a transmission circuit configured to output to the RFIC the PPDU that is beamformed according to the uplink beamforming matrix based on a value of an uplink beamforming-related second sub-field included in the trigger frame.
Embodiments of the present disclosure will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings in which:
In this description of the embodiments, Orthogonal Frequency Division Multiplexing (OFDM) or orthogonal frequency division multiplexing access (OFDMA)-based wireless communication systems, especially IEEE 802.11 standard, are discussed exemplarily. However, as will be appreciated by those skilled in the art, the subject matter may be favorably applied to any other communication systems having similar technical background and channel forms (e.g., cellular communication system such as long term evolution (LTE), LTE-advanced (LTE-A), new radio (NR), wireless broadband (WiBro), global system for mobile communication (GSM), or short range communication system such as Bluetooth, near field communication (NFC)).
In addition, various functions described below may be implemented or supported by artificial intelligence technology or one or more computer programs, and each of the programs consists of computer-readable program code and is embodied in a computer-readable medium. The terms “application” and “program” refer to one or more computer programs, software components, sets of instructions, procedures, functions, objects, classes, instances, related data, or portions thereof suitable for implementation of suitable computer-readable program code. The term “computer-readable program code” includes computer code of any type, including source code, object code, and executable code. The term “computer-readable medium” includes any type of medium that may be accessed by a computer, such as read only memory (ROM), random access memory (RAM), a hard disk drive, a compact disk (CD), a digital video disk (DVD), or any other type of memory. A “non-transitory” computer-readable medium excludes wired, wireless, optical, or other communication links that transmit transitory electrical or other signals. Non-transitory computer-readable media includes media in which data may be permanently stored, and media in which data is stored and may be overwritten later, such as a rewritable optical disc or a removable memory apparatus.
In various embodiments described below, a hardware approach is described as an example. However, because various example embodiments include technology using both hardware and software, the various example embodiments do not exclude a software-based approach.
In addition, terms referring to control information, terms referring to entries, terms referring to network entities, terms referring to messages, and terms referring to a component of an apparatus, used in the description to be described below, are examples for convenience of description. Accordingly, the embodiments are not limited to the terms described below, and other terms having equivalent technical meanings may be used.
Referring to
The access point may be referred to as a router, a gateway, etc., and the station may be referred to as a mobile station, a subscriber station, a terminal, a mobile terminal, a wireless terminal, user equipment, a user, etc. The station may be a mobile device such as a mobile phone, a laptop computer, a wearable device, etc., or may be a stationary device such as a desk top computer, a smart TV, etc. In the specification, the station (STA) may be referred to as a first device (or a third device), and the access point (AP) may be referred to as a second device.
The access points AP1 and AP2 may allocate at least one resource unit (RU) to at least one of the stations STA1 to STA4. The access points AP1 and AP2 may transmit data via the allocated at least one RU, and the at least one station may receive the data via the allocated at least one RU. In 802.11ax, the access points AP1 and AP2 may allocate a single RU to at least one station, but in 802.11be (hereinafter, EHT) or next generation IEEE 802.11 standards (hereinafter, EHT+), the access points AP1 and AP2 may allocate a multi-resource unit (MRU) including two or more RUs to at least one station. For example, the first access point AP1 may allocate the MRU to at least one of the first station STA1, the second station STA2, the third station STA3, and the fourth station STA4, and may transmit data via the allocated MRU.
The first and second access points AP1 and AP2 and the first to fourth stations STA1 to STA4 may communicate with one another by using a beamforming method. For example, performing beamforming for a single user may improve reception performance of the single user. Furthermore, multi-user beamforming may improve reception performance of the entire multi-users by removing interferences among the multi-users.
The access points AP1 and AP2 and the stations STA1 to STA4 may perform a channel sounding process for the beamforming, and the channel sounding process may be based on a sounding protocol. The access points AP1 and AP2 may perform the channel sounding process with the stations STA1 to STA4 supporting various protocol standards (e.g., EHT, EHT+, etc.).
The embodiments are to be described based on communication between the first station STA1 and the first access point AP1 for uplink beamforming of the first station STA1, and the embodiments may be applied to the second access point AP2 and the second to fourth stations STA2 to STA4.
In one or more embodiments, in order to reduce complexity and overhead of the signaling between the first station STA1 and the first access point AP1 for the uplink beamforming of the first station STA1, transmission/reception of sounding null data packet (NDP) or a compressed beamforming report (CBR) frame may be omitted. In addition, a comparative example in which the sounding NDP or the CBR frame is transmitted/received will be described later with reference to
In one or more embodiments, the first station STA1 may receive a physical layer protocol data unit (PPDU) including a trigger frame from the first access point AP1. In response to receiving the PPDU, the first station STA1 prepares an uplink beamforming matrix based on the PPDU, beamforms the PPDU according to the beamforming matrix, and may transmit the beamformed PPDU to the first access point AP1. In some embodiments, the PPDU may correspond to a media access control (MAC) packet data unit (MPDU). Detailed embodiments regarding this will be described below with reference to
In one or more embodiments, the first station STA1 may sequentially receive a null data packet announcement (NDPA) signal, the NDP, and the trigger frame from the first access point AP1, prepare the uplink beamforming matrix based on the NDP, beamform the PPDU according to the uplink beamforming matrix based on the trigger frame, and transmit the beamformed PPDU to the first access point AP1. Detailed embodiments regarding this will be described below with reference to
In one or more embodiments, the first station STA1 may receive an aggregated-MAC packet data unit (A-MPDU) including the trigger frame corresponding to the bandwidth aligned to the first station STA1 from the first access point AP1, prepare uplink beamforming matrix based on the A-MPDU, beamforms the A-MPDU according to the uplink beamforming matrix, and transmit the beamformed PPDU to the first access point AP1. Detailed embodiments regarding this will be described below with reference to
The first access point AP1 and the first station STA1 according to one or more embodiments may communicate with each other with minimum signaling in order to perform the uplink beamforming, and may effectively reduce the resource that is required to perform the uplink beamforming by utilizing the sent/received signals. As a result, the resource used for the data communication between the first access point AP1 and the first station STA1 may be increased, and then entire data throughput may be increased.
Referring to
The antenna 15_2 may receive a signal from the second wireless communication device 16 and provide the signal to the transceiver 15_4, or may transmit a signal provided from the transceiver 15_4 to the second wireless communication device 16. In some embodiments, the antenna 15_2 may include a plurality of antennas for multiple-input multiple-output (MIMO). In some embodiments, the antenna 15_2 may include a phased array for beamforming.
The transceiver 15_4 may process the signal received from the second wireless communication device 16 via the antenna 15_2, and may provide processed signal to the processing circuitry 15_6. In one or more examples, the transceiver 15_4 may process the signal provided from the processing circuitry 15_6, and may output the processed signal via the antenna 15_2. In some embodiments, the transceiver 15_4 may include an analog signal such as a low-noise amplifier, a mixer, a filter, a power amplifier, an oscillator, etc. In some embodiments, the transceiver 154 may process the signal received from the antenna 15_2 and/or the signal received from the processing circuitry 15_6 based on the control from the processing circuitry 15_6.
The processing circuitry 15_6 may process the signal received from the transceiver 15_4 so as to extract information transmitted from the second wireless communication device 16. For example, the processing circuitry 15_6 may extract the information by demodulating and/or decoding the signal received from the transceiver 15_4. In one or more examples, the processing circuitry 15_6 may generate a signal including information to be transmitted to the second wireless communication device 16 and provide the signal to the transceiver 15_4. For example, the processing circuitry 15_6 may provide the transceiver 15_4 with a signal that is generated by encoding and/or modulating data to be transmitted to the second wireless communication device 16. In some embodiments, the processing circuitry 15_6 may include a programmable element such as a central processing unit (CPU), a digital signal processor (DSP), etc., a reconfigurable element such as a field programmable gate array (FPGA), or an element providing fixed function such as an intellectual property (IP) core, etc. In some embodiments, the processing circuitry 15_6 may include a memory storing data and/or a series of instructions, or may access the memory.
In the specification, the transceiver 15_4 and/or the processing circuitry 15_6 performing operations may be simply referred to as the first wireless communication device 15 performing the corresponding operations. Accordingly, the operations performed by the access point may be performed by the transceiver and/or the processing circuitry included in the access point, and the operations performed by the station may be performed by the transceiver and/or the processing circuitry included in the station.
Referring to
At time t21, the first and second beamformers may each transmit the sounding NDP to the beamformee. In detail, each of the first and second beamformers may transmit the sounding NDP to the beamformee when a short interframe space (SIFS) time has passed after receiving the trigger frame. The beamformee may estimate the uplink channel based on the sounding NDP received from the first and second beamformers, and may generate information about the uplink channel status.
At time t41, the beamformee may transmit a compressed beamforming report (CBR) frame and the trigger frame to the first and second beamformers. In detail, the beamformee may transmit the CBR frame and the trigger frame to the first and second beamformers after SIFS time has passed from the point in time of receiving the sounding NDP. In some embodiments, the CBR frame may be referred to as a feedback frame, and the CBR frame may include uplink channel status information generated by the beamformee.
At time t51, each of the first and second beamformers may transmit beamformed PPDU to the beamformee. In detail, each of the first and second beamformers may transmit the beamformed PPDU to the beamformee after the SIFS time has passed from the point in time of receiving the trigger frame. Each of the first and second beamformers may determine the uplink beamforming matrix based on the uplink channel status information included in the CBR frame, and may generate the beamformed PPDU based on the determined uplink beamforming matrix.
In one or more examples, signaling between the time t11 and time t31 may be performed in order for each of the first and second beamformers to transmit the beamformed PPDU to the beamformee, and the signaling may increase the overhead in the wireless communication system as the number of beamformers communicating with the beamformee increases, thereby decreasing the total data throughput.
The embodiments that will be described below are provided to perform effective communication according to the uplink beamforming through a minimum signaling, for example, signaling between the time t11 and the time t31 is omitted.
Referring to
In operation S11, the station STA may identify a first sub-field related to the uplink beamforming. In one or more embodiments, the station STA may identify a value of the first sub-field included in a preamble of the received PPDU. The first sub-field may be a sub-field that is defined to indicate whether the station STA has to prepare the uplink beamforming matrix. In one or more embodiments, the first sub-field may be commonly used in another station communicating with the access point AP.
In operation S12, the station STA may prepare the uplink beamforming matrix. In one or more embodiments, the station STA may estimate a downlink channel based on the trigger frame when the first sub-field has a value indicating that the station STA has to prepare the uplink beamforming matrix, and may prepare the uplink beamforming matrix by determining the uplink beamforming matrix based on the estimated downlink channel. In detail, the station STA may prepare the uplink beamforming matrix by equalizing the downlink channel estimated based on a channel reciprocity with the uplink channel.
In operation S13, the station STA may identify a second sub-field related to the uplink beamforming. In one or more embodiments, the station STA may identify the second sub-field related to the uplink beamforming, included in the trigger frame. In one or more embodiments, the station STA may identify a value of the second sub-field included in the trigger frame. The second sub-field may be a sub-field that is defined to indicate whether the access point AP requests the uplink beamforming (or beamformed PPDU) from the station STA. In one or more embodiments, the second sub-field may be independently used in a certain station STA, and the second sub-field may be implemented as shown in
In operation S14, the station STA may transmit the beamformed PPDU to the access point AP. In one or more embodiments, the station STA may generate the beamformed PPDU based on the uplink beamforming matrix prepared in operation S12, when the second sub-field has a value indicating that the uplink beamforming has been requested.
Referring to
At time t22, the first and second beamformers estimate a downlink channel by decoding the trigger frame, and then may determine the uplink beamforming matrix based on the estimated downlink channel, when it is identified that the uplink beamforming matrix has to be prepared based on the first sub-field of the PPDU. The first beamformer may generate the beamformed PPDU based on the prepared uplink beamforming matrix and transmit the beamformed PPDU to the beamformee, when it is identified that the uplink beamforming is requested based on the second sub-field corresponding to the first beamformer. The second beamformer may generate the PPDU that is not beamformed and transmit the PPDU to the beamformee, when it is identified that the uplink beamforming is not requested based on the second sub-field corresponding to the second beamformer. In some embodiments, the first and second beamformers may transmit the beamformed PPDU to the beamformee or transmit the PPDU that is not beamformed to the beamformee, according to the value of the second sub-field that is in common in the first and second beamformers.
As understood by one of ordinary skill in the art, the embodiment of
Referring to
The L-STF field may include a short training OFDM symbol, and may be used for frame detection, automatic gain control (AGC), diversity detection, and coarse frequency/time synchronization. The L-LTF may include a long training OFDM symbol, and may be used for fine frequency/time synchronization and channel estimation. The L-SIG field may be used to transmit control information, and may include information about data rate and data length. In some embodiments, the fields from the RL-SIG field to the L-SIG field may be repeated.
The U-SIG field may include control information that is common for at least one station receiving the EHT PPDU 11a. The EHT-SIG field may have a variable modulation and coding scheme (MCS) and length. For example, when the EHT PPDU 11a may be transmitted to multi-users, an EHT-SIG field 12a may include a common field including common control information and a user-specified field including control information subjective to a user, as shown in
In addition, the trigger frame may be disposed in the data field Data of the payload.
Referring further to
Referring to
The trigger frames 21 and 31 may be used for transmitting a trigger-based (TB) PPDU. For example, the access point (or beamformee) may set an uplink bandwidth through the trigger frames 21 and 31, and may allocate a resource unit (RU) for uplink multi-user (MU) transmission. In some embodiments, the trigger frame may include a media access control (MAC) frame, and may be included in the PPDU (e.g., data field of PPDU). In some embodiments, the trigger frame may be included in the PPDU exclusive for the corresponding trigger frame.
Referring to
According to one or more embodiments, from among the plurality of sub-fields included in the common information field 22, the trigger-type sub-field may indicate a type of the trigger frame, and the receiving device may identify trigger frame variant based on the trigger-type sub-field. The trigger frame 21 may include a trigger dependent sub-field according to the trigger frame variant defined by the trigger type sub-field. According to the trigger frame variant, as shown in
Referring to
Referring to
Referring to
Referring to
In operation S21, the station STA may prepare the uplink beamforming matrix based on the NDP. In one or more embodiments, the station STA may estimate the downlink channel based on the NDP, and may determine the uplink beamforming matrix based on the estimated downlink channel to prepare the uplink beamforming matrix.
In operation S22, the access point AP may transmit the trigger frame to the station STA.
In operation S23, the station STA may identify the uplink beamforming-related sub-field included in the trigger frame. The uplink beamforming-related sub-field may match the second sub-field described above. In one or more embodiments, the station STA may identify a value of the sub-field included in the trigger frame.
In operation S24, the station STA may transmit the beamformed PPDU to the access point AP. In one or more embodiments, the station STA may generate the beamformed PPDU based on the uplink beamforming matrix prepared in operation S21, when the sub-field has a value indicating that the uplink beamforming has been requested.
Referring to
At time t23, the beamformee may transmit the NDP to the first and second beamformers. In one or more embodiments, each of the first and second beamformers may prepare the uplink beamforming matrix based on the NDP. Each of the first and second beamformers may prepare the uplink beamforming matrix when receiving the NDP from the access point, which may be planned in advance with the access point.
At time t43, when the SIFS time has passed from time t33, the beamformee may transmit the trigger frame to the first and second beamformers.
At time t53, the first beamformer may generate the beamformed PPDU based on the prepared uplink beamforming matrix and transmit the beamformed PPDU to the beamformee, when it is identified that the uplink beamforming is requested based on the sub-field corresponding to the first beamformer. The second beamformer may generate the PPDU that is not beamformed and transmit the PPDU to the beamformee, when it is identified that the uplink beamforming is not requested based on the sub-field corresponding to the second beamformer. In some embodiments, the first and second beamformers may transmit the beamformed PPDU to the beamformee or transmit the PPDU that is not beamformed to the beamformee, according to the value of the sub-field that is in common in the first and second beamformers.
In one or more embodiments, the trigger frame of
Referring to
At time t24, the beamformee may transmit the NDP to the first and second beamformers. In one or more embodiments, each of the first and second beamformers may prepare the uplink beamforming matrix based on the NDP. For example, each of the first and second beamformers may prepare the uplink beamforming matrix when receiving the NDP from the access point, which may be planned in advance with the access point.
At time t44, when the SIFS time has passed from time t34, the beamformee may transmit a beamforming report poll (BFRP) trigger frame to the first and second beamformers. The BFRP trigger frame may include information that is necessary for the first and second beamformers to send feedback regarding the channel status information about the downlink channel to the beamformer. For example, the BFRP trigger frame may include information about resources that are used in uplink transmission.
At time t54, when identifying that the uplink beamforming is requested from the sub-field corresponding to the first beamformer, the first beamformer may generate a compressed beamforming report (CBR) frame that is beamformed based on the prepared uplink beamforming matrix and the BFRP trigger frame, and then, may transmit the beamformed CBR frame to the beamformee. When identifying that the uplink beamforming is not requested from the sub-field corresponding to the second beamformer, the second beamformer may generate the CBR frame that is not beamformed based on the BFRP trigger frame and then transmit the PPDU to the beamformee. In some embodiments, the first and second beamformers may transmit the beamformed CBR frame to the beamformee or transmit the CBR frame that is not beamformed to the beamformee, according to the value of the sub-field that is in common in the first and second beamformers.
Referring to
In operation S31, the station STA may prepare the uplink beamforming matrix based on the NDP. In one or more embodiments, the station STA may estimate the downlink channel based on the NDP, and may determine the uplink beamforming matrix based on the estimated downlink channel to prepare the uplink beamforming matrix.
In operation S32, the access point AP may transmit a new type trigger frame to the station STA. In one or more embodiments, the new type trigger frame is newly defined via the trigger type sub-field included in the common information field of the trigger frame, and may be the trigger frame for requesting the station STA to perform the uplink beamforming and to transmit A-MPDU including the CBR frame and data. In some embodiments, the new type trigger frame may be defined to request the station STA to simultaneously trigger the CBR frame and the data. Detailed embodiment of the new type trigger frame will be described later with reference to
In operation S33, the station STA may identify the uplink beamforming-related sub-field included in the new type trigger frame. The uplink beamforming-related sub-field may match the second sub-field described above. In one or more embodiments, the station STA may identify a value of the sub-field included in the new type trigger frame.
In operation S34, the station STA may transmit the beamformed A-MPDU to the access point AP. In one or more embodiments, the station STA identifies that the received trigger frame is the new type trigger frame through the trigger type sub-field, and when the sub-field has a value indicating that the uplink beamforming is requested, the station STA may generate the beamformed A-MPDU based on the uplink beamforming matrix prepared in operation S31.
However, the embodiment of requesting the station STA to transmit the A-MPDU by using the new type trigger frame is an example, and the embodiments are not limited thereto. That is, the access point AP may request the station STA to transmit the A-MPDU by using the reserved bits in one of the common information field, the special user information field, and the user information field of the basic trigger frame.
Referring to
At a time t25, the beamformee may transmit the NDP to the first and second beamformers. In one or more embodiments, each of the first and second beamformers may prepare the uplink beamforming matrix based on the NDP. Each of the first and second beamformers may prepare the uplink beamforming matrix when receiving the NDP from the access point, and this may be planned in advance with the access point.
At time t45 after the SIFS time from time t35, the beamformee may transmit the new type trigger frame to the first and second beamformers.
At time t55, when identifying that the received trigger frame is the new type trigger frame and the uplink beamforming is requested from the sub-field corresponding to the first beamformer, the first beamformer may generate the beamformed A-MPDU based on the prepared uplink beamforming matrix and transmit the beamformed A-MPDU to the beamformee. In one or more embodiments, the beamformed A-MPDU may include the CBR frame and the data. When identifying that the received trigger frame is the new type trigger frame and the uplink beamforming is not requested from the sub-field corresponding to the second beamformer, the second beamformer may generate the A-MPDU and transmit the A-MPDU to the beamformee. In some embodiments, the first and second beamformers may transmit the beamformed A-MPDU to the beamformee or transmit the A-MPDU that is not beamformed to the beamformee, according to the value of the sub-field that is in common in the first and second beamformers.
Referring to the table TB2 of
Referring to
Referring to
In operation S41, the station STA may receive the MPDU matching the 80 MHz band thereof. For example, the upper end of the 80 MHz band may be allocated to the station STA for communication with the access point AP, and at this time, the station STA may receive the MPDU corresponding to the upper end of the 80 MHz band. In addition, the MPDU corresponding to the lower end of 80 MHz band may be received by another station STA.
In operation S42, the station STA may identify the uplink beamforming related first sub-field from the received MPDU. For example, the station STA may identify the value of the first sub-field included in the preamble of the received MPDU. The first sub-field may be a sub-field that is defined to indicate whether the station STA has to prepare the uplink beamforming matrix.
In operation S43, the station STA may prepare the uplink beamforming matrix. In one or more embodiments, the station STA may prepare the uplink beamforming matrix based on the trigger frame of the received MPDU when the station STA has a value indicating that the station STA has to prepare the uplink beamforming matrix.
In operation S44, the station STA may identify a second sub-field related to the uplink beamforming. In one or more embodiments, the station STA may identify the uplink beamforming related second sub-field from the trigger frame of the received MPDU. In one or more embodiments, the station STA may identify a value of the second sub-field included in the trigger frame. The second sub-field may be a sub-field that is defined or reserved to indicate whether the access point AP requests the uplink beamforming (or beamformed PPDU) from the station STA. For example, if this sub-field includes a value set to 1, it may be determined that uplink beamforming is requested.
In operation S45, the station STA may transmit the beamformed PPDU to the access point AP. In one or more embodiments, the station STA may generate the beamformed PPDU based on the uplink beamforming matrix prepared in operation S43, when the second sub-field has a value indicating that the uplink beamforming has been requested. In one or more examples, the station STA may beamform the PPDU based on the uplink beamforming matrix.
Referring to
At time t26, the first beamformer estimates a downlink channel in the first band by decoding the first trigger frame and then may determine the uplink beamforming matrix based on the estimated downlink channel, when it is identified that the uplink beamforming matrix has to be prepared based on the first sub-field of the first MPDU. The first beamformer may generate the beamformed PPDU based on the prepared uplink beamforming matrix and transmit the beamformed PPDU to the beamformee via the first band, when it is identified that the uplink beamforming is requested based on the second sub-field corresponding to the first beamformer of the first trigger frame. The second beamformer estimates a downlink channel in the second band by decoding the second trigger frame and then may determine the uplink beamforming matrix based on the estimated downlink channel, when it is identified that the uplink beamforming matrix has to be prepared based on the first sub-field of the second MPDU. The second beamformer may generate the beamformed PPDU based on the prepared uplink beamforming matrix and transmit the beamformed PPDU to the beamformee via the second band, when it is identified that the uplink beamforming is requested based on the second sub-field corresponding to the second beamformer of the second trigger frame.
As described above, the beamformee may individually direct the operations of preparing the uplink beamforming matrix in each of the first and second beamformers, by using the first sub-field of the first MPDU and the first sub-field of the second MPDU.
Referring to
In operation S51, the access point AP may set a communication parameter with the station STA based on the received capability information. In one or more embodiments, the access point AP may set the value of the first sub-field or the second sub-field according to the uplink beamforming-related capability of the station STA.
Referring to
In some embodiments, a transmission device for wireless communication in
Referring to
The receiving circuit 1200 may include an RX radio control circuit 1201, a frequency error correction circuit 1202, a clear-channel-assessment (CCA) circuit 1203, and a synchronization circuit 1204.
The demodulator 1300 may include a fast Fourier transform (FFT) circuit 1301, a channel estimator (CE) 1302, a signal to noise ratio (SNR) measuring circuit 1303, a channel tracker 1304, a reception beamforming (RX BF) circuit 1305, a pilot discrete Fourier transform (DFT) circuit 1306, a symbol demodulator 1307, a frame format detector 1308, a frequency/time tracker 1309, and a long-likelihood ratio (LLR) demapper 1310.
The transmission circuit 1400 may include a transmission (TX) radio control circuit 1401, an inverse fast Fourier transform (IFFT) circuit 1402, a low-density parity-check (LDPC) encoder 1403, a convolution encoder 1404, a TX BF circuit 1405, a data encoder 1406, and a preamble circuit 1407.
The processor 1500 may include an IEEE decoder 1501, a signal (SIG) decoder 1502, an LDPC decoder 1503, a Viterbi decoder 1504, and a data decoder 1505.
In one or more embodiments, the RFIC 1100 may receive the PPDU provided with the payload including the trigger frame through at least one antenna, and the RX BF circuit 1305 may prepare the uplink beamforming matrix based on the value of the uplink beamforming-related first sub-field included in the preamble of the PPDU. The transmission circuit 1400 may generate the beamformed PPDU that matches to the uplink beamforming matrix generated by the RX BF circuit 1305 based on the uplink beamforming-related second sub-field included in the trigger frame. In some embodiments, the transmission circuit 1400 may use at least one of the internal elements 1401, 1402, 1403, 1404, 1405, 1406, and 1407 in order to generate the beamformed PPDU.
In one or more embodiments, the RFIC 1100 may receive the NDPA signal and the NDP via the at least one antenna, and the RX BF circuit 1305 may prepare the uplink beamforming matrix based on the NDP. In one or more examples, the RFIC 1100 may receive the trigger frame including the uplink beamforming-related sub-field, and the transmission circuit 1400 may generate the beamformed PPDU matching to the uplink beamforming matrix generated by the RX BF circuit 1305 based on the value of the sub-field in the trigger frame.
In one or more embodiments, the RFIC 1100 may receive the A-MPDU including the first trigger frame corresponding to the first band through at least one antenna, and the RX BF circuit 1305 may prepare the uplink beamforming matrix based on the value of the uplink beamforming-related first sub-field included in the preamble corresponding to the first band in the A-MPDU. The transmission circuit 1400 may generate the beamformed PPDU that matches to the uplink beamforming matrix generated by the RX BF circuit 1305 based on the value of the uplink beamforming-related second sub-field included in the first trigger frame.
The transmission circuit 1400 may output the beamformed PPDU to the RFIC 1100 based on the above embodiments, and the RFIC 1100 may transmit the beamformed PPDU to another device through at least one antenna.
While the embodiments have been particularly shown and described with reference to embodiments thereof, it will be understood that various changes in form and details may be made therein without departing from the spirit and scope of the following claims.
Number | Date | Country | Kind |
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10-2023-0044789 | Apr 2023 | KR | national |
This application is based on and claims priority to U.S. Provisional Application No. 63/390,797, filed on Jul. 20, 2022, in the U.S. Patent and Trademark Office, and Korean Patent Application No. 10-2023-0044789, filed on Apr. 5, 2023, in the Korean Intellectual Property Office, the disclosures of which are incorporated by reference herein in their entireties.
Number | Date | Country | |
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63390797 | Jul 2022 | US |