This application is generally directed to the field of telecommunications. More particularly, this application is directed to the field of antenna configurations for telecommunications.
The present disclosure relates generally to a feature realization and method for implementation of wireless communication in a frequency division duplex (FDD) multi-band radio. Radio frequency (RF) technology is now mature enough to allow support of multiple simultaneous bands for transmission and/or reception through a common radio. A radio supporting multiple bands can be referred to as a multi-band (MB) radio. Customer demand for so-called MB radio is expected to increase to realize flexible configurations and applications. An important feature of an MB radio is to support dynamic power sharing between different bands and hence allow operators more flexibility in network deployment. From a site engineering point of view, an MB radio can reduce insertion loss for the antenna sharing multi-band scenario because no combiner is needed.
For MB radio, there are various possible structures based on combinations of different transmitter and receiver implementations as well as mapping of transceivers (e.g., radio units) to antenna ports in different ways.
Problems with Existing Solutions
There currently exist certain challenge(s) in preventing signals transmitted in different frequency bands of an MB radio from degrading signal reception sensitivity in the MB radio. Receiver (RX) sensitivity is an important parameter in determining the overall performance of a communication system; RX sensitivity translates directly into communication distance and reliability. For an FDD radio, RX sensitivity degradation due to an FDD radio's own transmitter (TX) signal is very important because RX sensitivity dominates cell range and throughput. For an FDD radio capable of multi-band operation, RX sensitivity degradation due to the MB radio's own TX signal could be much more severe than single-band FDD radio operation. First, RX sensitivity of one band will be degraded by an MB radio's own TX signal on the one band and by TX signals on other bands of the MB radio. Second, the MB radio TX signal will be wider, and the TX intermodulation products will be worse in an FDD radio because of the wider digital pre-distortion (DPD) linearization band width and an increase of the intermodulation products hitting the receiver band.
Problems of case 1, due to interference paths shown in
To avoid the interference paths of the first case (i.e., to support N bands), the number of antennas is 2*N (i.e., a dedicated antenna for each receiver and each transmitter).
Problems of case 2, due to interference paths shown in
Some embodiments of the present disclosure include the following:
An embodiment of the present disclosure may include a multi-band radio, which includes a first antenna, a second antenna that is physically separate from the first antenna, one or more transmitters configured to transmit a first transmit signal in a first transmit frequency band via the first antenna; and transmit a second transmit signal in a second transmit frequency band via the first antenna; and one or more receivers configured to receive a first receive signal in a first receive frequency band via the second antenna and receive a second receive signal in a second receive frequency band via the second antenna.
Intermodulation distortion components of the first transmit signal and the second transmit signal that fall within either the first receive frequency band or the second receive frequency band may be attenuated at the second antenna due to physical separation between the first antenna and the second antenna. The one or more receivers may include a first receive filter configured to filter signals from the second antenna that fall outside of the first receive frequency band to pass the first receive signal in the first receive frequency band; and a second receive filter configured to filter the signals from the second antenna that fall outside of the second receive frequency band to pass the second receive signal in the second receive frequency band. The one or more transmitters may each be coupled to the first antenna. The one or more receivers may each be coupled to the second antenna. The multi-band radio may operate in a frequency division duplex, FDD, mode, and leakage of the intermodulation distortion components that fall within either the first receive frequency band or the second receive frequency band may be attenuated prior to reception at the second antenna due to physical separation between the first antenna and the second antenna. The multi-band radio may be included in a User Equipment, UE. The multi-band radio may be included in a base station. The first transmit signal in the first transmit frequency band and the second transmit signal in the second transmit frequency band may be attenuated prior to reception at the second antenna due to physical separation between the first antenna and the second antenna.
Some embodiments include a method implemented in a multi-band radio. The method may include transmitting a first transmit signal in a first transmit frequency band via a first antenna; transmitting a second transmit signal in a second transmit frequency band via the first antenna; receiving a first receive signal in a first receive frequency band via a second antenna, the second antenna being physically separate from the first antenna; and receiving a second receive signal in a second receive frequency band via the second antenna. Some embodiments may include intermodulation distortion components of the first transmit signal and the second transmit signal that fall within either the first receive frequency band or the second receive frequency band are attenuated at the second antenna due to physical separation between the first antenna and the second antenna. The first transmit signal in the first transmit frequency band and the second transmit signal in the second transmit frequency band may be attenuated prior to reception at the second antenna due to physical separation between the first antenna and the second antenna.
Some additional embodiments may include a user equipment, UE. The UE may include a processing device and a transceiver system. The transceiver system may include a first antenna; a second antenna that is physically separate from the first antenna; one or more transmitters configured to transmit a first transmit signal in a first transmit frequency band via the first antenna and transmit a second transmit signal in a second transmit frequency band via the first antenna; and one or more receivers configured to receive a first receive signal in a first receive frequency band via the second antenna and receive a second receive signal in a second receive frequency band via the second antenna.
Some embodiments may include a method implemented in a User Equipment, UE, the method including transmitting a first transmit signal in a first transmit frequency band via a first antenna of the UE; transmitting a second transmit signal in a second transmit frequency band via the first antenna; receiving a first receive signal in a first receive frequency band via a second antenna of the UE, the second antenna being physically separate from the first antenna; and receiving a second receive signal in a second receive frequency band via the second antenna.
Some additional embodiments may include a base station, having: a processing device; and a transceiver system. The transceiver system may include a first antenna; a second antenna that is physically separate from the first antenna; one or more transmitters configured to transmit a first transmit signal in a first transmit frequency band via the first antenna and transmit a second transmit signal in a second transmit frequency band via the first antenna; and one or more receivers configured to receive a first receive signal in a first receive frequency band via the second antenna and receive a second receive signal in a second receive frequency band via the second antenna.
Some additional embodiments may include, a method implemented in a base station, the method including steps of: transmitting a first transmit signal in a first transmit frequency band via a first antenna of the base station; transmitting a second transmit signal in a second transmit frequency band via the first antenna; receiving a first receive signal in a first receive frequency band via a second antenna of the base station, the second antenna being physically separate from the first antenna; and receiving a second receive signal in a second receive frequency band via the second antenna.
The present disclosure includes the following illustrative drawings:
The figures may be best understood by reference to the following detailed description.
Generally, all terms used herein are to be interpreted according to their ordinary meaning in the relevant technical field, unless a different meaning is clearly given and/or is implied from the context in which it is used. All references to a/an/the element, apparatus, component, means, step, etc., are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise. The steps of any methods disclosed herein do not have to be performed in the exact order disclosed, unless a step is explicitly described as following or preceding another step and/or where it is implicit that a step must follow or precede another step. Any feature of any of the embodiments disclosed herein may be applied to any other embodiment, wherever appropriate. Likewise, any advantage of any of the embodiments may apply to any other embodiments, and vice versa. Other objectives, features, and advantages of the enclosed embodiments will be apparent from the following description.
Certain aspects of the present disclosure and their embodiments may provide solutions to the aforementioned or other challenges.
A solution proposed herein includes an antenna and filter configuration for FDD MB radio which can mitigate RX sensitivity degradation due to the MB radio's own TX signals.
Below is a list of examples of approaches for mitigating TX to RX interference:
Solutions proposed herein may include a new filter and antenna cross configuration for MB radio which mitigates the RX sensitivity degradation that is due to the MB radio's own transmitter. A solution is to use one antenna for all bands of the transmitter and a separate antenna for all bands of the receiver.
There are, proposed herein, various embodiments which address one or more of the issues disclosed herein.
Certain embodiments may provide one or more of the following technical advantage(s). The solution proposed herein may be compatible with an MB base station (BS) architecture and/or an MB user equipment (UE). Employing solutions proposed herein, the TX to RX blocking and interference may be mitigated or eliminated.
Some of the embodiments contemplated herein will now be described more fully with reference to the accompanying drawings. However, other embodiments are contained within the scope of the subject matter disclosed herein, such that the disclosed subject matter should not be construed as limited to only the embodiments set forth herein. Rather, these embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art.
Radio Node: As used herein, a “radio node” is either a radio access node or a wireless device.
Radio Access Node: As used herein, a “radio access node” or “radio network node” is any node in a radio access network of a cellular communications network that operates to wirelessly transmit and/or receive signals. Some examples of a radio access node include, but are not limited to, a base station (e.g., a New Radio (NR) base station (gNB) in a Third Generation Partnership Project (3GPP) Fifth Generation (5G) NR network or an enhanced or evolved Node B (eNB) in a 3GPP Long Term Evolution (LTE) network), a high-power or macro base station, a low-power base station (e.g., a micro base station, a pico base station, a home eNB, or the like), and a relay node.
Core Network Node: As used herein, a “core network node” is any type of node in a core network or any node that implements a core network function. Some examples of a core network node include, e.g., a Mobility Management Entity (MME), a Packet Data Network Gateway (PGW), a Service Capability Exposure Function (SCEF), a Home Subscriber Server (HSS), or the like. Some other examples of a core network node include a node implementing a Access and Mobility Function (AMF), a UPF, a Session Management Function (SMF), an Authentication Server Function (AUSF), a Network Slice Selection Function (NSSF), a Network Exposure Function (NEF), a Network Function (NF) Repository Function (NRF), a Policy Control Function (PCF), a Unified Data Management (UDM), or the like.
Wireless Device: As used herein, a “wireless device” is any type of device that has access to (i.e., is served by) a cellular communications network by wirelessly transmitting and/or receiving signals to a radio access node(s). Some examples of a wireless device include, but are not limited to, a User Equipment device (UE) in a 3GPP network and a Machine Type Communication (MTC) device.
Network Node: As used herein, a “network node” is any node that is either part of the radio access network or the core network of a cellular communications network/system.
Note that the description given herein focuses on a 3GPP cellular communications system and, as such, 3GPP terminology or terminology similar to 3GPP terminology is oftentimes used. However, the concepts disclosed herein are not limited to a 3GPP system.
Note that, in the description herein, reference may be made to the term “cell”; however, particularly with respect to 5G NR concepts, beams may be used instead of cells and, as such, it is important to note that the concepts described herein are equally applicable to both cells and beams.
The base stations 402 and the low-power nodes 406 provide service to wireless devices 412-1 through 412-5 in the corresponding cells 404 and 408. The wireless devices 412-1 through 412-5 are generally referred to herein collectively as wireless devices 412 and individually as wireless device 412. The wireless devices 412 are also sometimes referred to herein as UEs. The wireless devices 412 and/or the base stations 402 herein may be multi-band (MB) radio devices with a cross antenna configuration for wirelessly communicating over multiple frequency bands.
As an example, a cross antenna configuration for the MB radio wireless device 412 is depicted in
In other words, the first case in
In contrast, in the wireless device 412 in
Assuming 25 dB isolation between the two antennas:
As discussed above, both of the RX filter rejection needed at the TX band and the TX filter rejection needed at the RX band can be relaxed by 25 dB. The filter rejection relaxation allows a significant difference from previous filter design, especially for some 3GPP FDD bands, in which a distance between a TX band and an RX band is only several megahertz (MHz) or a few dozen MHz. The difference can save a high portion of the entire filter cost, and the size can be decreased by removing several resonators. Subsequently, due to filter rejection relaxation, filter production test time and cost can also be saved.
Because a TX signal will be attenuated by 25 dB before hitting a RX filter, the power handled by the RX filter is 25 dB lower, which will make it possible to use a small resonator for the RX filter, which means a smaller size, less weight, and less cost.
The MB radio generates a first transmit signal. This generation includes generation of the first transmit signal at baseband or Intermediate Frequency (IF), upconversion to a desired carrier frequency in a first transmit frequency band, and amplification. As described above, due to intermodulation distortion, once upconverted, the first transmit signal includes undesired intermodulation distortion components at frequencies other than the desired carrier frequency for the first transmit frequency band. In this example, at least one of the intermodulation distortion components falls within either a first receive frequency band of the MB radio or a second receive frequency band of the MB radio. Therefore, the intermodulation distortion components cause interference with one of the first receive frequency band and the second receive frequency band. The signal on the desired carrier frequency of the first transmit frequency band, which is outside the first receive frequency band and the second receive frequency band, may block the first receive frequency band or the second receive frequency band (e.g., by desensitizing the receiver amplifier).
The MB radio generates a second transmit signal. This generation includes generation of the second transmit signal at baseband or IF, upconversion to a desired carrier frequency in a second transmit frequency band, and amplification. As described above, due to intermodulation distortion, once upconverted, the second transmit signal includes undesired intermodulation distortion components at frequencies other than the desired carrier frequency for the second transmit band. In this example, at least one of the intermodulation distortion components falls within either the first receive frequency band of the MB radio or the second receive frequency band of the MB radio. Therefore, the intermodulation distortion components cause interference with one of the first receive frequency band and the second receive frequency band. The signal on the desired carrier frequency of the second transmit frequency band, which is outside the first receive frequency band and the second receive frequency band, may block the first receiver or the second receiver (e.g., by desensitizing the receiver amplifier).
The steps of one embodiment of the method of
Other signals received at the second antenna include the first transmit signal in the first transmit frequency band, the second transmit signal in the second frequency band, and the undesired intermodulation distortion components generated outside of the first and second transmit frequency bands by the first and second transmitters. These other signals can cause blocking and interference of the first and second receive frequency bands. However, because the receivers are connected to the second antenna, and not directly coupled to either of the transmitters, these other signals are attenuated (e.g., by 25 dB due) due to the antenna to antenna isolation. Therefore, signals such as the intermodulation components that fall outside of the first and second receive frequency bands can be more easily filtered (i.e., attenuated or removed), which allows the receivers to be designed with smaller, less expensive filters. Typically, the transmit signals (i.e., the desired components of the transmit signals in the first and second transmit bands) are stronger signals that can desensitize the receiver amplifiers, causing reception by those receivers to be blocked even though the transmit signals are outside of the receive frequency bands. By using the cross antenna configuration disclosed herein, the (e.g., 25 dB) attenuation of these transmit signals due to the physical separation between the two antennas reduces the filtering requirements for protecting against those signals in both of the receivers.
The MB radio filters the signals received via the second antenna using a first receive filter for the first receive band to thereby provide a received signal for the first receive band. Likewise, the MB radio filters the signals received via the second antenna using a second receive filter for the second receive band to thereby provide a received signal for the second receive band.
As used herein, a “virtualized” radio access node is an implementation of the radio access node 900 in which at least a portion of the functionality of the radio access node 900 is implemented as a virtual component(s) (e.g., via a virtual machine(s) executing on a physical processing node(s) in a network(s)). As illustrated, in this example, the radio access node 900 includes the control system 902 that includes the one or more processors 904 (e.g., CPUs, ASICs, FPGAs, and/or the like), the memory 906, and the network interface 908 and the one or more radio units 910 that each includes the one or more transmitters 912 and the one or more receivers 914 coupled to the one or more antennas 916, as described above. The control system 902 is connected to the radio unit(s) 910 via, for example, an optical cable or the like. The control system 902 is connected to one or more processing nodes 1000 coupled to or included as part of a network(s) 1002 via the network interface 908. Each processing node 1000 includes one or more processors 1004 (e.g., CPUs, ASICs, FPGAs, and/or the like), memory 1006, and a network interface 1008.
In this example, functions 1010 of the radio access node 900 described herein are implemented at the one or more processing nodes 1000 or distributed across the control system 902 and the one or more processing nodes 1000 in any desired manner. In some particular embodiments, some or all of the functions 1010 of the radio access node 900 described herein are implemented as virtual components executed by one or more virtual machines implemented in a virtual environment(s) hosted by the processing node(s) 1000. As will be appreciated by one of ordinary skill in the art, additional signaling or communication between the processing node(s) 1000 and the control system 902 is used in order to carry out at least some of the desired functions 1010. Notably, in some embodiments, the control system 902 may not be included, in which case the radio unit(s) 910 communicate directly with the processing node(s) 1000 via an appropriate network interface(s).
In some embodiments, a computer program including instructions which, when executed by at least one processor, causes the at least one processor to carry out the functionality of radio access node 900 or a node (e.g., a processing node 1000) implementing one or more of the functions 1010 of the radio access node 900 in a virtual environment according to any of the embodiments described herein is provided. In some embodiments, a carrier comprising the aforementioned computer program product is provided. The carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium (e.g., a non-transitory computer readable medium such as memory).
In some embodiments, a computer program including instructions which, when executed by at least one processor, causes the at least one processor to carry out the functionality of the UE 1200 according to any of the embodiments described herein is provided. In some embodiments, a carrier comprising the aforementioned computer program product is provided. The carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium (e.g., a non-transitory computer readable medium such as memory).
Any appropriate steps, methods, features, functions, or benefits disclosed herein may be performed through one or more functional units or modules of one or more virtual apparatuses. Each virtual apparatus may comprise a number of these functional units. These functional units may be implemented via processing circuitry, which may include one or more microprocessor or microcontrollers, as well as other digital hardware, which may include Digital Signal Processor (DSPs), special-purpose digital logic, and the like. The processing circuitry may be configured to execute program code stored in memory, which may include one or several types of memory such as Read Only Memory (ROM), Random Access Memory (RAM), cache memory, flash memory devices, optical storage devices, etc. Program code stored in memory includes program instructions for executing one or more telecommunications and/or data communications protocols as well as instructions for carrying out one or more of the techniques described herein. In some implementations, the processing circuitry may be used to cause the respective functional unit to perform corresponding functions according one or more embodiments of the present disclosure.
While processes in the figures may show a particular order of operations performed by certain embodiments of the present disclosure, it should be understood that such order is exemplary (e.g., alternative embodiments may perform the operations in a different order, combine certain operations, overlap certain operations, etc.).
Number | Date | Country | Kind |
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PCT/CN2019/094754 | Jul 2019 | CN | national |
This application claims the benefit of International Patent Application No. PCT/CN2019/094754, filed Jul. 4, 2019, the disclosure of which is hereby incorporated herein by reference in its entirety.
Filing Document | Filing Date | Country | Kind |
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PCT/IB2020/056301 | 7/3/2020 | WO | 00 |