Sub-band full-duplex communication system, method and base station

Abstract

This application provides a sub-band full-duplex communication system, method, and base station. The sub-band full-duplex communication system includes a first branch and a second branch. The first branch includes a transmit link and a reference link. The transmit link includes a DPD, DAC, mixer, power amplifier (PA), circulator, filter, and a first antenna array connected in sequence. The second branch includes a receive link, which includes a second antenna array, low-noise amplifier, mixer, and ADC connected in sequence. In the SBFD time slot, the first branch transmit link is used for downlink RF transmission of baseband signals, and the reference link collects the RF signal output by the PA as a reference signal. The second branch receive link is used for uplink RF transmission of wireless signals. Linear cancellation processing is performed on the received signal output by the receive link based on the reference signal. By separating the transmit and receive antenna arrays and combining linear cancellation processing, interference between uplink and downlink signals is reduced.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a sub-band full-duplex communication system, method and base station. Background Technology

[0002] 5G networks have been commercially deployed on a large scale, with high-bandwidth time-division duplex (TDD) networks primarily utilizing spectrum above 3 GHz. Existing networks based on 5G TDD spectrum exhibit significant uplink coverage shortcomings. For example, if a network deployment is designed to achieve 100 Mbps downlink and 5 Mbps uplink coverage, downlink coverage satisfaction is greater than 80%, while uplink coverage satisfaction is less than 50%, indicating a substantial uplink coverage problem.

[0003] Traditional TDD frame structures divide time-frequency resources along a time dimension, with some time allocated to uplink and some to downlink. In existing networks primarily using enhanced mobile broadband (eMBB) applications, typical downlink-to-uplink time allocation ratios are 7:3, 8:2, etc., with uplink accounting for a relatively small proportion. To improve uplink coverage, sub-band full-duplex technology is introduced. Compared to TDD frame structures, sub-band full-duplex frame structures can effectively improve uplink coverage. In traditional TDD frame structures, each time slot's uplink and downlink traffic exclusively occupy the entire frequency domain. Sub-band full-duplex technology achieves this by performing sub-band-level frequency division multiplexing of the large bandwidth spectrum used in TDD. This is achieved by configuring uplink and downlink transmission resources at different frequencies in some time slots. Since more uplink and downlink time slots are configured, uplink and downlink latency can be reduced. More uplink resources can be flexibly configured, which helps to enhance uplink coverage and increase capacity. However, since uplink and downlink transmissions are carried out in the same time slot, the uplink and downlink can affect each other. In particular, the downlink can affect the uplink, which can easily lead to uplink receiving channel congestion and affect uplink coverage. Summary of the Invention

[0004] In view of the above, embodiments of the present invention provide a sub-band full-duplex communication system, method and base station, which reduces interference between uplink and downlink signals by combining separate settings of transmit and receive antenna arrays and linear cancellation processing.

[0005] In a first aspect, embodiments of this application provide a sub-band full-duplex communication system, comprising: a first branch including a transmit link and a reference link, the transmit link including a digital predistortion (DPD), a digital-to-analog converter (DAC), a mixer, a power amplifier (PA), a circulator, a filter, and a first antenna array connected in sequence; a second branch including a receive link, the receive link including a second antenna array, a filter, a low-noise amplifier, a mixer, and an analog-to-digital converter (ADC) connected in sequence; in the SBFD time slot, the transmit link is used for downlink radio frequency transmission of baseband signals; the receive link is used for uplink radio frequency transmission of wireless signals; the reference link acquires the amplified radio frequency signal output by the PA to obtain a reference signal, and performs linear cancellation processing on the digital received signal output by the receive link based on the reference signal.

[0006] Using the above technical solution, in the SBFD time slot, the transmit link is used for downlink radio frequency transmission of baseband signals; the receive link is used for uplink radio frequency transmission of wireless signals; the first antenna array and the second antenna array are set separately to improve the isolation between the transmit and receive antenna arrays; and the radio frequency signal output by the PA is collected by the reference link as a reference signal, and the digital received signal output by the receive link is linearly canceled according to the reference signal to further reduce the impact of downlink signals on uplink signals.

[0007] In some embodiments, the linear cancellation processing of the digital received signal based on the reference signal can be performed in the second branch receiving link (before the received signal is sent to the baseband) or in the baseband.

[0008] In one possible implementation of the first aspect above, the reference link includes a coupler, a mixer, and an analog-to-digital converter connected in sequence. The coupler is used to acquire the radio frequency signal after the PA. The mixer and the analog-to-digital converter perform down-conversion and sampling in sequence to convert the radio frequency signal into a digital signal so that the digital signal can be used as a reference signal and the received signal output by the receiving link can be linearly canceled based on the reference signal.

[0009] Using the above technical solution, the radio frequency signal after PA is acquired by the coupler, and the mixer and analog-to-digital converter perform down-conversion and sampling in sequence. The radio frequency signal is converted into a digital signal, which is used as a reference signal. The digital received signal output by the ADC of the receiving link is linearly canceled according to the reference signal.

[0010] In one possible implementation of the first aspect described above, the reference link further includes a filter, one end of which is connected to a coupler and the other end of which is connected to the mixer.

[0011] Using the above technical solution, if the filter is an adjustable filter, the signal acquired by the coupler is filtered by the adjustable filter to reduce energy in the downlink subband range and avoid limiting the dynamic range of the ADC in the reference link. Simultaneously, the adjustable filter can adjust the passband bandwidth according to actual needs to improve the applicability of the subband full-duplex system. One implementation of the adjustable filter includes multiple filters with different bandwidths, which can be selected by switching between them as needed. Of course, in other embodiments, the filter can also be a fixed-bandwidth filter.

[0012] In one possible implementation of the first aspect described above, the reference link further includes a switching unit and a low-noise amplifier, one end of the switching unit being connected to the mixer and one end of the low-noise amplifier being connected to the circulator; when the other end of the switching unit is connected to the filter, the first antenna array is used to transmit downlink signals; when the other end of the switching unit is connected to the other end of the low-noise amplifier, the first antenna array is used to receive uplink signals.

[0013] During the SBFD time slot, the first branch transmit link operates, converting the baseband signal to radio frequency for downlink transmission. Simultaneously, the switch and filter in the reference link are switched on, operating in reference channel mode to sample the transmitted radio frequency signal after the PA in real time to obtain a reference signal. The second branch receive link operates normally, receiving the uplink signal from the second antenna array port. Due to signal leakage to the receive link, the received uplink signal contains both service signals and self-interference signals. Linear cancellation processing is performed on the received signal based on the reference signal obtained from the reference channel sampling to eliminate the self-interference component in the uplink signal. The two branches, through a combination of antenna isolation and linear cancellation, eliminate the impact of downlink on the uplink.

[0014] By adopting the above technical solution, the function of the first antenna array can be adjusted according to uplink and downlink requirements. For example, it can be used to transmit downlink signals or receive uplink signals.

[0015] In one possible implementation of the first aspect described above, the receiving link further includes a filter, one end of which is connected to the low-noise amplifier, and the other end of which is connected to the mixer. During the SBFD time slot, the passband bandwidth of the adjustable filter matches the UL subband, reducing DL subband energy and preventing ADC saturation in the receiving link. During the UL time slot, the passband bandwidth of the adjustable filter switches to the entire frequency band, without affecting the uplink full-band received signal. Because the downlink signal causes strong interference to the uplink receiving link, the receiving link and reference link have high requirements for ADC dynamic range, posing a significant challenge to engineering implementation. Adding a filter reduces the dynamic range requirements of the receiving link and reference link, facilitating engineering implementation.

[0016] When the filters of the receiving link and the reference link are fixed bandwidth filters, only fixed subband bandwidth configuration can be supported.

[0017] When the filters of the receiving link and the reference link are adjustable bandwidth filters, the UL subband bandwidth can be flexibly configured.

[0018] In one possible implementation of the first aspect described above, the first branch includes a plurality of the transmitting links and a plurality of the reference links, and the second branch includes a plurality of receiving links. In the first branch, the first antenna array, the transmitting links, and the reference links are in a one-to-one correspondence. In the second branch, the second antenna array and the receiving links are in a one-to-one correspondence.

[0019] The plurality of receiving radio frequency chains and the plurality of transmitting radio frequency chains have a one-to-one correspondence with the target antenna array, which may be a first antenna array or a second antenna array.

[0020] In one possible implementation of the first aspect described above, the first branch is located in a first module, and the first module can be configured to implement the function of the second branch. For example, the first module can be configured by software to implement the function of the second branch. In this way, the functions of different branches can be implemented using the same hardware module.

[0021] In one possible implementation of the first aspect described above, the first branch is located in the first module, and the second branch is located in the second module, wherein the first module and the second module are two independent modules.

[0022] By adopting the above technical solution, the independence and flexibility of the first and second branches are improved by placing the first branch and the second branch in two independent modules.

[0023] In one possible implementation of the first aspect described above, the second branch further includes an auxiliary transmission link, which has the same structure as the transmission link and reuses the second antenna array and filter of the receiving link. The auxiliary transmission link and the receiving link operate alternately. When the auxiliary transmission link is in operation, the second antenna array is used to transmit signals; when the receiving link is in operation, the second antenna array is used to receive signals.

[0024] The second aspect provides a base station including a sub-band full-duplex communication system as described in any of the first aspects.

[0025] In one possible implementation of the second aspect above, the base station further includes a baseband processing unit (BBU) and an active antenna processing unit (AAU), the AAU including a subband full-duplex communication system as described in any of the first aspects, the BBU being used for power-reduced scheduling of downlink resource blocks near the edge of the uplink subband.

[0026] The third aspect provides a subband full-duplex communication method, comprising: in the SBFD time slot, sequentially transmitting a baseband signal via a digital predistortion (DPD), a digital-to-analog converter (DAC), a mixer, a power amplifier (PA), a circulator, a filter, and a first antenna array through a transmit link; sequentially transmitting a wireless signal via a second antenna array filter, a low-noise amplifier, a mixer, and an analog-to-digital converter (ADC) through a receive link; and acquiring the amplified radio frequency signal output by the PA through a reference link to obtain a reference signal, and performing linear cancellation processing on the received signal output by the receive link based on the reference signal.

[0027] In one possible implementation of the third aspect above, the reference link acquires the amplified radio frequency signal output by the PA to obtain a reference signal, and performs linear cancellation processing on the received signal output by the ADC based on the reference signal, including: acquiring the amplified radio frequency signal of the PA through a coupler; converting the radio frequency signal into a digital signal through a mixer and an analog-to-digital converter; using the digital signal as the reference signal, and performing linear cancellation processing on the received signal output by the receiving link based on the reference signal.

[0028] In one possible implementation of the third aspect described above, the method further includes: filtering the radio frequency signal acquired by the coupler using a filter, and sending the filtered radio frequency signal to the mixer. The filter is either an adjustable filter or a fixed-bandwidth filter.

[0029] In one possible implementation of the third aspect above, the method further includes: in the downlink time slot or SBFD time slot, one end of the switching unit is connected to the mixer, and the other end of the switching unit is connected to the filter, and the first antenna array is used to transmit downlink signals; in the uplink time slot, one end of the low-noise amplifier is connected to the circulator, one end of the switching unit is connected to the mixer, and the other end of the switching unit is connected to the other end of the low-noise amplifier, and the first antenna array is used to receive uplink signals.

[0030] In one possible implementation of the third aspect described above, the first branch includes multiple transmit links and multiple reference links, and the second branch includes multiple receive links. In the first branch, the first antenna array, the transmit links, and the reference links have a one-to-one correspondence. In the second branch, the second antenna array and the receive links have a one-to-one correspondence.

[0031] In one possible implementation of the third aspect above, the first branch is located in the first module, and the second branch is located in the second module, wherein the first module and the second module are two independent modules.

[0032] It should be understood that the technical effects brought about by any of the designs in the second to third aspects can be referred to the beneficial effects of the corresponding methods provided above, and will not be repeated here. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of an SBFD time slot structure.

[0034] Figure 2 This is a schematic diagram of an SBFD time slot structure provided in an embodiment of this application.

[0035] Figure 3 This is a schematic diagram of a sub-band full-duplex communication system provided in an embodiment of this application.

[0036] Figure 4 This is a schematic diagram of another sub-band full-duplex communication system provided in an embodiment of this application.

[0037] Figure 5 This is a schematic diagram of another sub-band full-duplex communication system provided in an embodiment of this application.

[0038] Figure 6 This is a schematic diagram of a signal change provided in an embodiment of this application.

[0039] Figure 7 This is a schematic diagram of another SBFD time slot structure provided in an embodiment of this application.

[0040] Figure 8 This is a schematic diagram of another sub-band full-duplex communication system provided in an embodiment of this application.

[0041] Figure 9 This is a schematic diagram of the module composition of a sub-band full-duplex communication system provided in an embodiment of this application.

[0042] Figure 10 This is a schematic diagram of the modules of a base station according to an embodiment of this application.

[0043] Figure 11This is a schematic diagram of power reduction scheduling provided in an embodiment of this application.

[0044] Explanation of main component symbols

[0045] Sub-band full-duplex communication system 100

[0046] First Branch Road 10

[0047] Transmission Link 11

[0048] First antenna array 111

[0049] Baseband Modem 112

[0050] DPD 113

[0051] DAC 114

[0052] Mixer 115

[0053] PA 116

[0054] Circulator 117

[0055] Filters 118 and 212

[0056] Reference Link 12

[0057] Coupler 121

[0058] Mixer 122

[0059] ADC 123, 215

[0060] LIC 124

[0061] Filters 125, 219

[0062] Switching unit 126

[0063] Second Branch Road 20

[0064] Receive link 21

[0065] Second antenna array 211

[0066] Low noise amplifiers 213, 127

[0067] Mixer 214

[0068] Auxiliary transmission link 22

[0069] The following detailed description, in conjunction with the accompanying drawings, further illustrates this application. Detailed Implementation

[0070] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of embodiments of this application, words such as "exemplary" or "for example" are used to identify examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0071] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in this application's specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. It should be understood that, unless otherwise stated, "a plurality of" means two or more, and "and / or" includes any and all combinations of one or more of the associated listed items.

[0072] First, let's introduce the technical terms used in the embodiments of this application:

[0073] 1. Subband full duplex (SBFD)

[0074] Subband full-duplex is achieved by configuring uplink and downlink transmission resources at different frequencies in some time slots. Since more uplink and downlink time slots are configured, uplink and downlink latency can be reduced; more uplink resources can be flexibly configured, which helps to enhance uplink coverage and increase capacity.

[0075] To enhance uplink coverage and uplink capacity, existing communication systems have begun to widely adopt subband full-duplex technology. This application uses the application of subband full-duplex technology to base stations as an example for illustration.

[0076] in, Figure 1 This is a schematic diagram of a subband full-duplex frame structure. Figure 1 Of the ten time slots, each is a frequency-duplexed (SBFD) time slot capable of simultaneous uplink (UL) (receive link) and downlink (DL) (transmit link) transmission, such as... Figure 1 As shown, the UL subband occupies 4MHz, and the two DL subbands each occupy 8MHz. Since uplink and downlink transmissions are carried out simultaneously in the same time slot, the uplink and downlink affect each other. In particular, the downlink affects the uplink, which can easily lead to uplink receiving channel blockage, affecting uplink coverage and sensitivity.

[0077] To address the aforementioned issues, this application provides a sub-band full-duplex communication system. By separating the transmit and receive antennas, the mutual interference between the uplink and downlink is reduced. Furthermore, linear cancellation technology is used to linearly cancel the received signal of the uplink to remove self-interference components from the received signal and reduce the impact of the downlink on the uplink.

[0078] Figure 2 This is a schematic diagram of an SBFD time slot structure as an example of this application. Figure 2 The frequency band includes five time slots. The first to fourth time slots divide the entire frequency band into UL and DL sub-bands, where the UL sub-band can be used for uplink transmission (e.g., ...). Figure 2 The X MHz band is used for uplink transmission, while the DL subband can be used for downlink transmission. The fifth time slot dedicates the entire frequency band to uplink transmission.

[0079] It is understood that in other embodiments, the number of SBFD time slots may be greater than or less than 5 time slots. This application embodiment only uses 5 time slots as an example for illustration.

[0080] Figure 2 In the SBFD time slot, neither the uplink UL nor the downlink DL can occupy the entire frequency resource range. The UL subband occupies the central part of the frequency band, while the DL subband is located on both sides of the frequency band.

[0081] In one embodiment, the UL subband can be symmetrical about the frequency band center, so that the bandwidth of the lower DL subband and the upper DL subband will be equal. However, in other embodiments, the UL subband can be configured at any position in the frequency band, in which case the bandwidth of the lower DL subband is different from the bandwidth of the upper DL subband.

[0082] It is understood that in other embodiments, the SBFD time slot can be located in any of the five time slots, meaning that any of the five time slots can be used.

[0083] Please see Figure 3 , Figure 3 This is a schematic diagram of a sub-band full-duplex communication system provided in an embodiment of this application. Figure 3 The neutron band full-duplex communication system 100 includes a first branch 10 and a second branch 20. The first branch 10 includes a transmit link 11 and a reference link 12, and the second branch 20 includes a receive link 21. Figure 3 The sub-band full-duplex communication system shown can be applied to Figure 2The SBFD time slots shown are used as follows: transmit link 11 is used for downlink signal transmission in the first to fourth time slots, receive link 21 is used for uplink signal reception in the first to fourth time slots, and the first branch 10 and the second branch 20 are both used for uplink signal reception in the fifth time slot. The number and aperture of the equivalent array antennas are increased to enhance uplink coverage.

[0084] Figure 3 In the above, the transmit link 11 includes a first antenna array 111, and the receive link 21 includes a second antenna array 211. There is a gap between the first antenna array 111 and the second antenna array 211, for example, 50 cm. During the SBFD time slot, the first antenna array 111 is used for transmitting signals, while the second antenna array 211 is used for receiving signals. The physical spacing between the first antenna array 111 and the second antenna array 211 reduces interference between downlink transmit signals and the uplink in the same SBFD time slot.

[0085] In other embodiments, an isolator (not shown) is provided between the first antenna array 111 and the second antenna array 211 to increase the isolation between the first antenna array 111 and the second antenna array 211 and reduce interference between them.

[0086] The aforementioned reference link is used to collect the radio frequency signal output from the power amplifier PA116 of the transmission link 11 as a reference signal. Based on the reference signal, linear cancellation technology is used to remove the self-interference component in the uplink received signal, so as to further reduce the interference between the downlink transmitted signal and the uplink received signal.

[0087] Please see again Figure 3 The transmission link 11 also includes: a baseband modem BB Tx 112, a digital predistortion module DPD 113, a digital-to-analog converter DAC 114, a mixer 115, a power amplifier PA 116, a circulator CIRC 117, and a filter RFBF 118.

[0088] To make it clear, Figure 3 Only a single transmit RF chain is shown. Multiple transmit RF chains can be integrated into the first branch 10. Each transmit RF chain is configured to convert baseband signals into RF transmit signals. It is understood that in other embodiments, the number of RF chains in the sub-band full-duplex communication system can be set as needed. The number of reference links is the same as the number of transmit links, and they are in a one-to-one correspondence.

[0089] When the subband full-duplex communication system 100 transmits signals: the baseband modem 112 includes a base station transmitter 1121 (BB ​​Tx) for generating baseband signals for each transmit RF chain; the baseband transmitter 1121 generates baseband signals for each transmit RF chain; then the baseband signals are sent to the DPD 113, which performs pre-distortion processing, and the digital-to-analog converter DAC 114 performs conversion processing to obtain an analog signal;

[0090] The analog signal is then amplified by power amplifier PA116, and then passed through circulator 117 and filter 118 to filter out out-of-band spurious signals. Finally, the energy is radiated into free space by the first antenna array 111.

[0091] The reference link 12 includes a coupler 121, a mixer 122, and an analog-to-digital converter (ADC) 123. The coupler 121 acquires the radio frequency (RF) signal amplified by the power amplifier PA116 in the transmission link and sends the RF signal to the mixer 122 and the ADC 123. After processing the RF signal, the mixer 122 and the ADC 123 obtain a digital reference signal. Then, the baseband processing unit LIC124 performs cancellation processing on the received signal according to the digital parameter signal, that is, it eliminates the self-interference component in the uplink received signal through linear interference cancellation technology.

[0092] It is understood that in other embodiments, LIC124 may be located in the second branch 20. For example, LIC124 may be part of the receiving link 21, so that the received signal has been canceled by LIC124 of the receiving link 21 before being transmitted to the BBU.

[0093] The receiving link 21 also includes: a filter RF BF212, a low-noise amplifier LNA213, a mixer 214, and an analog-to-digital converter ADC215.

[0094] To make things clear, Figure 3 Only a single receiver RF chain is shown in the diagram. Each receiver RF chain is configured to convert the received RF signal into a baseband signal. Figure 3 In this system, multiple receiver RF chains are integrated into the second branch 20. The sub-band full-duplex communication system may include multiple receiver RF chains. Each receiver RF chain is used to down-convert the RF signal received from it in the second antenna array from RF to baseband.

[0095] When the sub-band full communication system 100 receives signals: the second linear array 211 receives the uplink RF signal. The low-noise amplifier 213 amplifies the filtered signal with low noise for uplink transmission, and then sends it to the mixer 214 and ADC 215. The ADC 215 processes the signal from the low-noise amplifier 213 to obtain the received digital signal.

[0096] The LIC124 then uses linear interference cancellation technology to linearly cancel the received signal and the parameter signal, thereby removing the self-interference component from the signal. The reference signal includes the transmitted baseband signal, its nonlinear components, and noise. The received signal includes both self-interference and the desired signal.

[0097] The aforementioned sub-band full-duplex communication system 100 acquires the amplified signal from PA116 in the transmit link 11 via reference link 12 as a reference signal. This reference signal includes the nonlinearity and noise generated by the downlink transmit signal. Compared to separately acquiring the signal processed by filter 118 in the transmit link 11 for analog linear cancellation and acquiring the baseband signal for digital linear / nonlinear cancellation, this application eliminates the need for nonlinear modeling, reducing the cancellation cost. Furthermore, reference link 12 switches between the reference channel and the receive channel operating modes via a switch, reducing hardware implementation costs.

[0098] In some embodiments, the receiving link 21 further includes a filter 219, one end of which is connected to a low-noise amplifier (LNA) 213, and the other end is connected to a mixer 214. During the SBFD time slot, the passband bandwidth of the adjustable filter matches the UL subband, reducing leakage energy in the DL subband and preventing ADC saturation in the receiving link. During the UL time slot, the passband bandwidth of the adjustable filter switches to the entire frequency band, without affecting the uplink full-band received signal. Because the downlink signal causes strong interference to the uplink receiving link, the receiving link and reference link have high requirements for ADC dynamic range, posing a significant challenge to engineering implementation. Adding filters reduces the dynamic range requirements of the receiving link and reference link, facilitating engineering implementation. When the filters in the receiving link and reference link are fixed-bandwidth filters, only fixed subband bandwidth configuration is supported. When the filters in the receiving link and reference link are adjustable-bandwidth filters, flexible configuration of the UL subband bandwidth is supported.

[0099] In some embodiments, the reference link 12 further includes a filter 125 that receives the analog signal collected by the coupler 121. After filtering the analog signal, the filter 125 sends the signal to the mixer 122 and the ADC 123. The filter 125 can be an adjustable filter. By adding an adjustable filter, the applicability range of the analog-to-digital converter (ADC) can be improved, and the dynamic range of the ADC can be avoided. Of course, in other embodiments, the filter 125 can also be a fixed bandwidth filter.

[0100] Please see Figure 3Reference link 12 also includes a switching unit 126 and a low-noise amplifier 127. In the first to fourth time slots, filter 125 is connected to mixer 122 through switching unit 126, that is, one end of switching unit 126 is connected to filter 125 and the other end is connected to mixer 122. In the fifth time slot, low-noise amplifier 127 is connected to mixer 122 through switching unit 126, that is, one end of switching unit 126 is connected to low-noise amplifier 127 and the other end is connected to mixer 122. Low-noise amplifier 127 is connected to circulator 117 and multiplexes the first antenna array 111, filter 118 and circulator 117 in transmit link 11. At this time, the first antenna array 111 is used to receive uplink signals. Then, the received uplink signals are filtered by filter 118 and amplified by low-noise amplifier 213 for uplink transmission. Then, they are sent to mixer 122 and ADC 123 through switching unit. ADC 123 processes the uplink signals from low-noise amplifier 213 to obtain digital received signals. Thus, the two ends of the switching unit are connected to different device units, and the first antenna array performs different functions. In this embodiment, when the switching unit is connected to the low-noise amplifier and the mixer, the first antenna array is used to receive uplink signals. Since both the first and second antenna arrays are used to receive uplink signals at this time, uplink coverage is improved.

[0101] Please see Figure 4 This is a schematic diagram of a sub-band full-duplex communication system provided in an embodiment of this application. Figure 4 Neutron band full-duplex communication system and Figure 3 The sub-band full-duplex communication system in the text is similar to 100, but the difference is:

[0102] Figure 4 The sub-band full-duplex communication system 100 includes a first branch 10 comprising multiple transmit links 11 and multiple reference links 12, with each transmit link 11 corresponding to each reference link 12. The second branch 20 comprises multiple receive links 21, each receive link 21 being configurable as a receive RF chain, and each transmit link 11 being configurable as a transmit RF chain. Therefore, each receive RF chain or transmit RF chain corresponds to a target antenna array, which is either a first antenna array or a second antenna array. Figure 4 The first branch 10 includes multiple transmit links 11 and multiple reference links 12. Therefore, the baseband modem 112 and the baseband transmitter 1121 generate baseband signals for each transmit RF chain.

[0103] In the first to fourth time slots, i.e., SBFD time slots, multiple transmit RF chains in the first branch are used for downlink signal transmission, and multiple receive RF chains in the second branch are used for uplink signal reception. In the fifth time slot, the reference link of the first branch is configured for receive mode, and both the receive RF chains in the second branch are used for uplink signal reception. Therefore, within the SBFD time slots, the first antenna array of the transmit RF chain is used for signal transmission, and the second antenna array of the receive RF chain is used for signal reception; while in the fifth time slot, both the first and second antenna arrays are used for signal reception.

[0104] Furthermore, in the embodiments of this application, each antenna corresponds to one RF chain, and the independence between each RF chain is relatively strong, making it easy to adjust the number of antenna arrays and RF chains according to requirements.

[0105] Please see Figure 5 , Figure 5 This is a schematic diagram of a sub-band full-duplex communication system provided in an embodiment of this application. Figure 5 Neutron band full-duplex communication system and Figure 4 The sub-band full-duplex communication system in the text is similar, but the differences are:

[0106] Figure 5 The reference link also includes a filter. In the SBFD time slot, the bandwidth and location of the UL subband differ between operators. The filter is an adjustable filter, whose filtering range can be adjusted according to the bandwidth and location of the UL subband. By adding an adjustable filter to the reference link, the applicability of the subband full-duplex communication system is improved. Of course, in other embodiments, the filter can also be a fixed-bandwidth filter.

[0107] Please see Figure 6 This is a schematic diagram of signal change provided in an embodiment of this application, wherein... Figure 6 In the middle (a), the signal spectrum after PA amplification of the first branch acquired by the reference link is shown. Figure 6 Figure (b) shows the signal spectrum after processing by the tunable filter. The signal in Figure (b) is then converted to a digital signal by an ADC, and this digital signal is then filtered by a digital filter to become... Figure 6 The reference signal is shown in (c). This reference signal is then canceled out with the received signal from the second branch in the BBU or the receiving link. Thus, by adding an adjustable filter to the reference link, the filtering range of the filter can be adjusted according to different needs.

[0108] Please see Figure 7 This is a schematic diagram of another SBFD time slot format provided in the embodiments of this application. Figure 7The system includes five time slots. The first time slot is a pure downlink time slot, where all frequency resources are used for downlink transmission. The second to fourth time slots are SBFD time slots, with some frequencies used for uplink transmission and others for downlink transmission. The fifth time slot is a pure uplink time slot, where all frequencies are used for base station uplink transmission. It is understood that in other embodiments, the number of SBFD time slots may be greater than or less than five; this embodiment only uses five time slots as an example.

[0109] Please see Figure 8 , Figure 8 This is a schematic diagram of a sub-band full-duplex communication system provided in an embodiment of this application. Figure 8 Neutron band full-duplex communication system and Figure 5 Similar to the sub-band full-duplex communication system in [the text], the sub-band full-duplex communication system 100 includes a first branch 10 and a second branch 20. The first branch 10 includes multiple transmit links 11 and multiple reference links 12, and the second branch 20 includes multiple receive links 21. The difference is that the second branch 20 also includes multiple auxiliary transmit links 22. Thus, in [the text], Figure 7 In the first time slot, both the first branch 10 and the second branch 20 are used for downlink signal transmission. In the second to fourth time slots, the transmitting link 11 in the first branch 10 is used for downlink signal transmission, and the reference link 12 collects the transmitted signal as a reference signal. The second branch 20 is used for uplink signal reception. In the fifth time slot, both the first branch 10 and the second branch 20 are used for uplink signal reception.

[0110] Furthermore, the auxiliary transmission link 22 has the same structure as the transmission link 11. The auxiliary transmission link 22 includes a digital-to-analog converter (DAC), a mixer, a power amplifier (PA), a circulator, a filter, and an antenna array. The receiving link 21 and the auxiliary transmission link 22 multiplex the circulator, filter, and antenna array.

[0111] According to the base station time slot configuration, the receiving link 21 and the auxiliary transmitting link 22 are controlled to work alternately. For example, in the first time slot, the auxiliary transmitting link 22 is working and the second antenna array 211 is used to transmit downlink signals; in the second to fourth time slots, the receiving link 21 is working and is used to receive uplink signals; in the fifth time slot, the receiving link 21 is working and is used to receive uplink signals.

[0112] Please see Figure 9 , Figure 9 This is a schematic diagram of a sub-band full-duplex communication system provided in an embodiment of this application. Figure 9 Neutron band full-duplex communication system and Figure 5 Similar to neutron-band full-duplex communication systems, the difference lies in: Figure 5The embodiment is implemented within a base station module. Figure 9 By Figure 5 The first branch shown is integrated into a single module, and the function of the second branch can be implemented by another module with identical hardware through software configuration. Then, by splicing two independent and identical hardware modules, the transmit and receive antennas are separated. Software control enables both modules to support sub-band full-duplex operation. Thus, a single module can operate in TDD mode, and two spliced ​​modules can operate in sub-band full-duplex mode.

[0113] In other embodiments, the sub-band full-duplex communication system includes a first branch and a second branch. The first branch is located in a first module, and the second branch is located in a second module. The first module and the second module are two independent modules. Thus, by placing the first branch and the second branch in different modules, transmission and reception separation is achieved.

[0114] Please see Figure 9 , Figure 9 The first and second modules are respectively connected to the baseband processing unit (BBU).

[0115] Please see Figure 10 , Figure 10 This is a schematic diagram of a base station module provided in an embodiment of this application. The base station includes a baseband processing unit (BBU) and an active antenna processing unit (AAU). The AAU includes a sub-band full-duplex communication system as described in the above embodiment. The BBU and AAU transmit data and communicate via the enhanced universal public radio interface (eCPRI).

[0116] Due to the above embodiments, such as Figure 11 As shown, the subband full-duplex communication system employs subband full-duplex technology. Within the SBFD time slot, downlink transmission signals affect uplink reception signals, leading to strong blocking of the received signal. This strong blocking is affected by phase noise in the receiving link, causing an increase in the noise floor of resource blocks in the UL subband that connect to the DL subband. The BBU adaptively adjusts the transmit power based on the actual transmission conditions of each channel or signal and UE feedback information, causing resource blocks RB near the edge of the UL subband to transmit at reduced power, while minimizing the impact on downlink services.

[0117] Specifically, the BBU is used to reduce the power of downlink RBs near the edge of the uplink subband in order to reduce the impact of phase noise on the rise of the noise floor at the edge of the UL subband.

[0118] In some embodiments, the base station may be a base station that supports Massive MIMO.

[0119] This application also provides a sub-band full-duplex communication method, which can be applied to the sub-band full-duplex communication system described in any of the above embodiments.

[0120] The subband full-duplex communication method includes: in the SBFD time slot, the baseband signal is transmitted downlink via the digital predistortion (DPD), digital-to-analog converter (DAC), mixer, power amplifier (PA), circulator, filter, and first antenna array of the transmit link; the RF signal is transmitted uplink via the second antenna array, filter, low-noise amplifier, mixer, and analog-to-digital converter (ADC) of the receive link; the RF signal output by the PA is acquired by the reference link as a reference signal, and the received signal output by the ADC of the receive link is linearly canceled based on the reference signal.

[0121] In some embodiments, the reference link acquires the radio frequency signal output by the PA as a reference signal, and performs linear cancellation processing on the received signal output by the ADC of the receiving link based on the reference signal, including:

[0122] The amplified radio frequency signal from the PA is acquired via a coupler.

[0123] Radio frequency signals are converted into digital signals by a mixer and an analog-to-digital converter;

[0124] The LIC uses the digital signal as a reference signal and performs linear cancellation processing on the received signal output by the receiving link based on the reference signal.

[0125] The LIC can be set in the BBU or in the receiving link.

[0126] In some embodiments, the method further includes:

[0127] The radio frequency signal acquired by the coupler is filtered by a filter to reduce the energy of the DL subband signal and avoid limiting the dynamic range of the ADC.

[0128] In some embodiments, the method further includes:

[0129] In the downlink time slot or SBFD time slot, one end of the switching unit is connected to the mixer, and the other end of the switching unit is connected to the filter. The first antenna array is used to transmit downlink signals.

[0130] In the uplink time slot, one end of the low-noise amplifier is connected to the circulator, one end of the switching unit is connected to the mixer, and the other end of the switching unit is connected to the other end of the low-noise amplifier. The first antenna array is used to receive uplink signals.

[0131] In some embodiments, the number of the transmitting link and the receiving link is multiple, and the multiple transmitting links and the multiple receiving links are configured as multiple transmitting radio frequency chains and multiple receiving radio frequency chains. Each receiving radio frequency chain is configured to convert a received radio frequency signal into a baseband signal, and each transmitting radio frequency chain is configured to convert a baseband signal into a radio frequency transmitting signal.

[0132] The plurality of receiving radio frequency chains and the plurality of transmitting radio frequency chains have a one-to-one correspondence with the target antenna array, which may be a first antenna array or a second antenna array.

[0133] In some embodiments, the first branch is disposed in a first module, and the first module can be configured to implement the function of the second branch. For example, the first module can be configured by software to implement the function of the second branch. In this way, the functions of different branches can be implemented using the same hardware module.

[0134] In some embodiments, the first branch is disposed in the first module, and the second branch is disposed in the second module, wherein the first module and the second module are two independent modules.

[0135] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of hardware embodiments, software embodiments, or embodiments combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. This computer program code can be stored in a computer-readable storage medium capable of directing a computer or other programmable data processing device to function in a particular manner.

[0136] In addition, embodiments of this application also provide an apparatus, which may specifically be a chip, component, or module. The apparatus may include a connected processor and a memory; wherein the memory is used to store computer execution instructions, and when the apparatus is running, the processor may execute the computer execution instructions stored in the memory to cause the chip to execute the network congestion control methods in the above-described method embodiments.

[0137] Through the above description of the embodiments, those skilled in the art can clearly understand that, for the sake of convenience and brevity, only the division of the above functional modules is used as an example. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0138] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules or modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules or components may be combined or integrated into another device, or some features may be ignored or not executed. Furthermore, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or modules may be electrical, mechanical, or other forms.

[0139] The modules described as separate components may or may not be physically separate. A component shown as a module can be one or more physical modules; that is, it can be located in one place or distributed in multiple different locations. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0140] Furthermore, the functional modules in the various embodiments of this application can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module. The integrated modules described above can be implemented in hardware or as software functional modules.

[0141] If the integrated module is implemented as a software functional module and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, the technical solutions of the embodiments of this application, essentially, or the parts that contribute to the prior art, or all or part of the technical solutions, can be embodied in the form of a software product. This software product is stored in a storage medium and includes several instructions to cause a device (which may be a microcontroller, chip, etc.) or processor to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0142] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A sub-band full-duplex communication system, characterized in that, include: The first branch includes a transmission link and a reference link. The transmission link includes a digital predistortion (DPD), a digital-to-analog converter (DAC), a mixer, a power amplifier (PA), a circulator, a filter, and a first antenna array connected in sequence. The second branch includes a receiving link, which comprises a second antenna array, a filter, a low-noise amplifier, a mixer, and an analog-to-digital converter (ADC) connected in sequence; the receiving link is used to down-convert the wireless signal from the antenna port of the second antenna array and sample it to obtain a digital received signal. The reference link is used to acquire the radio frequency signal output by the PA of the transmitting link, use the radio frequency signal as a reference signal, and perform linear cancellation processing on the digital received signal output by the receiving link based on the reference signal. The reference link includes a coupler, a mixer, and an analog-to-digital converter connected in sequence. The coupler is used to acquire the radio frequency signal processed by the PA. The mixer and the analog-to-digital converter down-convert the radio frequency signal and convert it into a digital signal so that the digital signal can be used as a reference signal. The digital received signal output by the ADC of the receiving link is linearly canceled according to the reference signal. The reference link further includes a filter, one end of which is connected to a coupler, and the other end of which is connected to the mixer; The reference link further includes a switching unit and a low-noise amplifier, one end of the switching unit being connected to the mixer, and one end of the low-noise amplifier being connected to the circulator; When in downlink time slot or SBFD time slot, the other end of the switching unit is connected to the filter, and the first antenna array is used to transmit downlink signals; During the uplink time slot, the other end of the switching unit is connected to the low-noise amplifier, and the first antenna array is used to receive the uplink signal.

2. The sub-band full-duplex communication system as described in claim 1, characterized in that, The first branch includes multiple transmitting links and multiple reference links, and the second branch includes multiple receiving links. In the first branch, the first antenna array, the transmitting links, and the reference links are in a one-to-one correspondence. In the second branch, the second antenna array and the receiving links are in a one-to-one correspondence.

3. The sub-band full-duplex communication system as described in claim 1, characterized in that, The receiving link also includes a filter, one end of which is connected to the low-noise amplifier and the other end of which is connected to the mixer.

4. The sub-band full-duplex communication system as described in claim 2, characterized in that, The first branch is set in the first module, and the first module can be configured to implement the function of the second branch.

5. The sub-band full-duplex communication system as described in claim 1, characterized in that, The first branch is located in the first module, and the second branch is located in the second module. The first module and the second module are two independent modules.

6. The sub-band full-duplex communication system as described in claim 2, characterized in that, The second branch also includes an auxiliary transmission link, which has the same structure as the transmission link and reuses the second antenna array and filter of the receiving link. The auxiliary transmission link and the receiving link work alternately. When the auxiliary transmission link is in operation, the second antenna array is used to transmit signals; when the receiving link is in operation, the second antenna array is used to receive signals.

7. A base station, characterized in that, Includes the sub-band full-duplex communication system as described in any one of claims 1 to 6.

8. The base station as described in claim 7, characterized in that, The base station further includes a baseband processing unit (BBU) and an active antenna processing unit (AAU), wherein the AAU includes a subband full-duplex communication system as described in any one of claims 1 to 6, and the BBU is used to perform power reduction scheduling on downlink resource blocks near the edge of the uplink subband.

9. A sub-band full-duplex communication method, characterized in that, include: In the SBFD time slot, the baseband signal is transmitted downlink sequentially through the digital predistortion (DPD), digital-to-analog converter (DAC), mixer, power amplifier (PA), circulator, filter, and first antenna array of the transmission link. The wireless signal is transmitted uplink via the second antenna array, filter, low-noise amplifier, mixer, and analog-to-digital converter (ADC) of the receiving link in sequence. The reference link acquires the radio frequency signal output by the PA as a reference signal, and performs linear cancellation processing on the received signal output by the receiving link based on the reference signal. The process of acquiring the radio frequency signal output by the PA to obtain the reference signal and performing linear cancellation processing on the received signal output by the ADC of the receiving link based on the reference signal includes: The amplified radio frequency signal from the PA is acquired via a coupler. The radio frequency signal is converted into a digital signal using a mixer and an analog-to-digital converter; The LIC uses the digital signal as a reference signal and performs linear cancellation processing on the received signal output by the receiving link based on the reference signal; The method further includes: The radio frequency signal acquired by the coupler is filtered by a filter, and the filtered radio frequency signal is transmitted to the mixer. In the SBFD time slot, one end of the switching unit is connected to the mixer, and the other end of the switching unit is connected to the filter. The first antenna array is used to transmit downlink signals. In the uplink time slot, one end of the low-noise amplifier is connected to the circulator, one end of the switching unit is connected to the mixer, and the other end of the switching unit is connected to the other end of the low-noise amplifier. The first antenna array is used to receive uplink signals.

10. The sub-band full-duplex communication method as described in claim 9, characterized in that, The first branch includes multiple transmit links and multiple reference links, and the second branch includes multiple receive links. In the first branch, the first antenna array, the transmit links, and the reference links are in a one-to-one correspondence. In the second branch, the second antenna array and the receive links are in a one-to-one correspondence.

11. The sub-band full-duplex communication method as described in claim 10, characterized in that, The first branch is set in the first module, and the first module is configured to implement the function of the second branch.

12. The sub-band full-duplex communication method as described in claim 10, characterized in that, The first branch is located in the first module, and the second branch is located in the second module. The first module and the second module are two independent modules.

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