Communication system

Abstract

The invention relates to a communication system. The communication system comprises a baseband module, a radio frequency module and a radio frequency front-end module, the radio frequency interface signal processing module is coupled between the radio frequency module and the radio frequency front end module; the radio frequency interface processing module is configured to at least receive a first radio frequency signal from the radio frequency module; wherein the radio frequency interface signal processing module comprises a signal processing device, and the signal processing device is configured to execute a digital pre-distortion operation at least based on a first radio frequency signal so as to obtain a second radio frequency signal with digital pre-distortion information. According to the scheme provided by the invention, the nonlinear problem of the signal generated by the power amplifier can be weakened or eliminated, the power, efficiency and bandwidth of the power amplifier are further improved, meanwhile, the adaptability of the high-performance pre-distortion method in a radio frequency system is improved, and the development complexity and the application cost of the application of the high-performance pre-distortion method are reduced.

Description

Technical Field

[0001] The present invention relates to the field of communications, and in particular to a communication system. Background Art

[0002] The development of communication systems has always been limited by the material and process level of RF components, facing the contradiction between transmission bandwidth, transmission power, signal linearity and system efficiency. Increasing the transmission power may cause signal distortion or poor linearity, while pursuing linear signal without distortion may reduce system efficiency and increase heat dissipation burden.

[0003] Figures 1 to 3 This is a schematic diagram of the transmitting part of an existing communication system. A general communication system includes two parts: transmitting and receiving, and each part may have multiple channels working simultaneously or non-simultaneously.

[0004] RF power amplifiers (RF PAs or PAs) are used to amplify small RF signals to increase the transmission distance. Due to material limitations, the design of RF PAs requires trade-offs among important indicators such as output power, linearity, efficiency, and output bandwidth.

[0005] In order to reduce or eliminate nonlinear problems such as those caused by power amplifiers, current RF enhancement technologies are mainly concentrated in digital intermediate frequency positions or baseband chips / modules. However, this solution has a high threshold for use and a fixed system structure, which limits the application of RF enhancement functions in the terminal field and is only used in a small range of high-power base station equipment.

[0006] like Figure 1 and Figure 2 The system in the needs FPGA to support the implementation of digital signal processing functions in the baseband to achieve the purpose of optimizing RF performance, such as reducing or eliminating the nonlinear effects caused by the power amplifier. In both solutions, the digital signal processing module is located in the baseband chip / module and is usually implemented using FPGA. However, FPGA has the disadvantages of large area, high production cost and high power consumption, so the system performance and cost will be affected by the performance of FPGA and RF chip / module. The system shown in Figure 3 requires the FPGA in the baseband module and the digital signal processing unit 310 in the highly integrated RF module 300 to work together to achieve the purpose of optimizing RF performance. The digital signal processing unit 310 in the highly integrated RF module 300 has limited performance and poor adaptability and can only be used in limited application scenarios. The RF module 300 needs to cooperate with the FPGA and needs to be connected using a high-speed digital interface. The high cost of this interface will lead to an increase in the overall product cost. Summary of the invention

[0007] In response to the technical problems existing in the prior art, the present application proposes a communication system, including a communication system, including: a baseband module, a radio frequency module, and a radio frequency front-end module; and, a radio frequency interface signal processing module coupled between the radio frequency module and the radio frequency front-end module; the radio frequency interface processing module is configured to at least receive a first radio frequency signal from the radio frequency module; wherein the radio frequency interface signal processing module includes a signal processing device, and the signal processing device is configured to perform a digital predistortion operation based on at least the first radio frequency signal, thereby obtaining a second radio frequency signal with digital predistortion information.

[0008] In particular, the system, wherein the RF interface signal processing module includes: a down-conversion unit, configured to receive the first RF signal and perform a down-conversion operation to obtain the first analog signal; an up-conversion unit, configured to perform an up-conversion operation on the second analog signal generated by the signal processing device to obtain a second RF signal; the signal processing device, coupled between the up-conversion unit and the down-conversion unit, configured to receive the first analog signal and convert it into a first digital signal, and perform digital pre-distortion processing on the first digital signal to obtain a second digital signal and convert it into the second analog signal.

[0009] In particular, in the system, the RF interface signal processing module also includes a feedback channel, which is configured to receive an RF feedback signal from the RF front-end module, convert the RF feedback signal into a third analog signal and provide it to the signal processing device.

[0010] In particular, in the system, the RF interface signal processing module is also configured to receive multiple RF analog signals and RF feedback signals.

[0011] In particular, in the system, the feedback channel in the RF interface signal processing module includes: a feedback selection switch, coupled to the RF front-end module, configured to select and output multiple RF feedback signals; a down-conversion subunit, configured to down-convert the RF feedback signal and provide the third analog signal generated after the conversion to the signal processing device; and a high-frequency clock subunit, configured to generate the local oscillator signal required by the down-conversion subunit.

[0012] In particular, the system, wherein the signal processing device includes: a first analog-to-digital converter, configured to convert the first analog signal into a first digital signal; a core processor, coupled to the first analog-to-digital converter, configured to process the first digital signal and output a second digital signal with at least digital predistortion information; a digital-to-analog converter, coupled to the core processor, configured to convert the second digital signal into a second analog signal.

[0013] In particular, in the system, the signal processing device also includes a second analog-to-digital converter, coupled to the core processor, configured to receive the third analog signal, convert the third analog signal into a third digital signal and provide it to the core processor.

[0014] Particularly, in the system, the signal processing device obtains a second RF signal with predistortion information based on the first RF signal and the RF feedback signal.

[0015] In particular, the system, wherein the system is a wifi router, wherein the radio frequency interface signal processing module further comprises a clock selection switch configured to select local oscillator signals generated by a plurality of high-frequency clock subunits.

[0016] In particular, as described in any of the above communication systems, the communication system also includes a base station, a drone, a mobile phone, a walkie-talkie, a car, a satellite, or a wireless camera.

[0017] The solution proposed in this application lowers the design threshold for the system to use the pre-distortion method, increases the versatility of the pre-distortion method, can weaken or eliminate the nonlinear problem of the signal generated by the power amplifier, and further improves the power, efficiency and bandwidth that the power amplifier can achieve under the same signal quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Below, the preferred embodiments of the present application will be further described in detail with reference to the accompanying drawings, wherein: Figures 1 to 3 It is a schematic diagram of the transmitting part of the existing communication system; Figure 4 Shown is a module schematic diagram of a communication system according to an embodiment of the present application; Figure 5 Shown is a schematic diagram of a radio frequency interface signal processing module according to an embodiment of the present application; Figure 6 Shown is a module schematic diagram of a signal processing device according to an embodiment of the present application; Figure 7 Shown is a module schematic diagram of an existing WiFi router; Figure 8 Shown is a module schematic diagram of a WiFi router according to one embodiment of the present application; Fig. 9 Shown is a schematic diagram of the modules of an existing base station; Fig.10 Shown is a module schematic diagram of another existing base station. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0020] In the following detailed description, reference may be made to the various specification drawings that are part of the present application and are used to illustrate specific embodiments of the present application. In the accompanying drawings, similar reference numerals describe substantially similar components in different figures. The various specific embodiments of the present application are described below in sufficient detail so that a person of ordinary skill in the art with relevant knowledge and skills in the art can implement the technical solutions of the present application. It should be understood that other embodiments may also be used or structural, logical or electrical changes may be made to the embodiments of the present application.

[0021] The technologies, methods and devices known to those skilled in the art may not be discussed in detail, but where appropriate, the technologies, methods and devices shall be considered as part of the specification. The lines between the units in the drawings are only for the convenience of explanation, indicating that at least the units at both ends of the lines are communicating with each other, and are not intended to limit the unconnected units from being unable to communicate. In addition, the number of lines between two units is intended to indicate at least the number of signals involved in the communication between the two units or at least the output terminals, and is not intended to limit the two units to only be able to communicate with each other through the signals shown in the figure.

[0022] The current plan is through Figure 1 or Figure 2 The digital signal processing module 120 or 220 or Figure 3The digital signal processing unit 310 in the system is used to compensate the digital signal in an attempt to solve problems such as signal linearity. In addition, it is necessary to match peripheral devices such as ADC and DAC and corresponding clock circuits, which makes the system design face challenges in terms of interface and electrical characteristics matching, and will also further increase the cost, area and power consumption of the system. In addition, the signal processing algorithm is not targeted and cannot process the signal according to the usage scenario and signal quality. At present, there are some applications or devices that do not have such digital signal processing modules, such as WiFi routers. Or, based on cost considerations, for some equipment manufacturers such as base station manufacturers, the current expectation or trend is to provide base station equipment that does not include a digital processing module or only provides a digital processing module including basic functions. This situation causes the communication system to either reduce the efficiency of the power amplifier or exchange high costs for signal linearity performance. But more expectations are to achieve the improvement of linearity while achieving optimal efficiency at a lower cost and a better design solution.

[0023] The existing technology directly converts the baseband signal to generate a signal of the corresponding frequency, and then outputs it through the RF front-end module. The RF front-end module mainly completes the functions of sending and amplifying RF signals. The modulation devices and power amplifier devices included in it are analog semiconductor devices, and their performance is restricted by the physical properties of semiconductors. While ensuring low EVM / ACR, the signal transmission power and system transmission efficiency must be output as high as possible. The up-conversion module and the RF front-end module must have extremely high linearity, which greatly increases the requirements for hardware design.

[0024] The communication system proposed in the present application includes a radio frequency interface signal processing module with pre-distortion processing capability and independent of the baseband and radio frequency modules, which pre-compensates the radio frequency signal output by the power amplifier, so that the radio frequency signal of the system has good linearity, improves the performance of the communication system, reduces the requirements for the physical properties of devices such as the power amplifier, and greatly increases the adaptability of the high-performance pre-distortion method in the radio frequency system, reducing the development complexity and application cost of the application of the high-performance pre-distortion method.

[0025] Figure 4 The module schematic diagram of the communication system according to an embodiment of the present application is shown. It includes a baseband module 41, a radio frequency module 42 coupled to the baseband module 41, and a radio frequency front-end module 44. The radio frequency interface signal processing module 43 is coupled between the radio frequency module 42 and the radio frequency front-end module 44. The radio frequency front-end module 44 may include a power amplifier unit 441, which is configured to receive the radio frequency transmission signal output by the radio frequency interface signal processing module 43; it may also include a coupler coupled to the output end of the power amplifier unit 441, whose output end is coupled to the radio frequency interface signal processing module 43, and configured to feed back the signal output by the power amplifier with nonlinear information to the radio frequency interface signal processing module 43.

[0026] In some embodiments of the present application, the baseband module 41 and the RF module 42 may be co-located in the baseband chip. In other embodiments, the RF module 42 may be a highly integrated RF module.

[0027] However, no matter what the structure of the baseband module and the RF module is, the RF interface signal processing module can be used to improve the linearity of the signal.

[0028] According to one embodiment, the RF interface signal processing module 43 is configured to receive the RF signal output by the RF module 42, change the RF signal to a low frequency, and then perform operations such as digital mirror correction, digital predistortion processing, and peak clipping processing to obtain a RF transmission signal with digital predistortion information.

[0029] According to one embodiment, the RF interface signal processing module 43 raises the signal processed by, for example, a pre-distortion operation back to the frequency point of the received RF signal and outputs it.

[0030] According to an embodiment, the RF interface signal processing module 43 may also be configured to obtain a RF transmission signal with digital predistortion information based at least on the RF signal and the RF feedback signal.

[0031] Figure 5 The schematic diagram of the RF interface signal processing module according to one embodiment of the present application is shown, which can be coupled between the RF module and the RF front-end module. The RF interface signal processing module proposed in the present application can be located between the RF module and the RF front-end module which communicate using RF signals and are separate from each other.

[0032] According to one embodiment, as shown in the figure, the RF interface signal processing module 50 may include a down-conversion unit 510, configured to down-convert the output of the RF module to obtain an analog signal; a signal processing device 520, coupled to the output end of the down-conversion unit 510, configured to convert the analog signal into a digital signal and process it, such as pre-distortion processing, and convert the processed digital signal into an analog signal for output; an up-conversion unit 530, coupled to the signal processing device 520, configured to up-convert the analog signal output by the signal processing device 520 to obtain a RF transmission signal; a feedback channel, configured to feed back a RF feedback signal with nonlinear information received from the outside to the signal processing device 520. The RF feedback signal may include a RF signal with nonlinear information output by a power amplifier. In one embodiment, the feedback channel may be coupled to the output end of the coupler in the RF front-end module.

[0033] According to an embodiment, the signal processing device 520 can integrate multiple signal processing functions, including image correction (QEC), pre-distortion (PD), clipping processing (CFR), power detection (PD), digital filtering (FIR) and DC offset correction (DC-Offset EQ). These functions can greatly improve the quality of the RF signal output by the power amplifier, so that the power amplifier can work with higher efficiency and power, while reducing the performance index requirements for RF and analog devices.

[0034] According to one embodiment, the feedback channel can monitor the output of the external RF front-end module in real time, and can help the signal processing device 520 to perform real-time calibration and adjustment, thereby improving the performance and reliability of the entire communication system. This closed-loop calibration function can not only improve the nonlinearity and anti-aging performance of devices (such as power amplifiers, up-conversion units, digital-to-analog converters), but also improve the yield and consistency. According to one embodiment, the feedback channel can support multiple channels, such as 2 / 4 / 6 / 8... channel input time-division switching.

[0035] According to one embodiment, the feedback channel includes a feedback selection switch 550, which can be coupled to a coupler of the RF front-end module and is configured to select and output multiple RF feedback signals; a high-frequency clock subunit 560, which is configured to provide a local oscillator signal, and the frequency of the local oscillator signal provided by the high-frequency clock subunit 560 is greater than or equal to the frequency of the RF signal; a down-conversion subunit 570, which is coupled to the feedback selection switch 550 and the high-frequency clock subunit 560, and is configured to apply the local oscillator signal from the high-frequency clock subunit 560 to the output of the feedback selection switch 550, down-convert the signal output by the feedback selection switch 550, and output an analog signal to the signal processing device 520.

[0036] According to another embodiment of the present application, for application scenarios where real-time tracking of the signal output by the power amplifier is not required, the coefficients of the power amplifier output are calibrated at the factory, and the coefficients are recorded in a non-volatile memory for use by the signal processing device each time the power is turned on.

[0037] According to an embodiment, the RF interface signal processing module 50 may further include a control unit (not shown) configured to control various parts in the RF interface signal processing module. The control unit may include a processor with control processing capabilities such as an MCU.

[0038] The RF interface signal processing module proposed in this application may include an enhanced algorithm for improving signal linearity and be independent of the baseband and RF modules, and be applied in different architectures, with higher processing performance, adaptability and economy. In addition, the pre-distortion related parameters can be adjusted in real time, and the baseband module or highly integrated RF module is no longer required for digital signal processing and debugging.

[0039] Figure 6 The module diagram of the signal processing device according to one embodiment of the present application is shown. In the present application, "analog" refers to a relatively low-frequency signal whose center frequency is near zero frequency; "radio frequency" refers to a relatively high-frequency signal whose center frequency is outside zero frequency, such as 900MHz.

[0040] As shown in the figure, the signal processing device 60 may include: a switch 630, an analog-to-digital converter 640 coupled thereto, the output end of the analog-to-digital converter 640 coupled to the input end of the core processor 650, the output end of the core processor 650 coupled to the input end of the digital-to-analog converter 640', the output end of the digital-to-analog converter 640' coupled to the switch 630', and the main control 610 coupled or electrically connected to all other units.

[0041] According to one embodiment, an output terminal of the switch 630' is configured to provide a processed high-speed analog signal to the outside of the signal processing device 60. According to other embodiments, in some application scenarios, the signal processing device 60 may not include the switch 630 and the switch 630'.

[0042] According to one embodiment, the main control 610 can be electrically connected to all other units and configure the initialization parameters and startup processes of other modules, communicate with external MCU and other control modules, exchange commands and data, and monitor the working status of the signal processing device 60 system, and realize abnormal recovery processing and maintainable and monitorable functions.

[0043] According to one embodiment, the analog-to-digital converter 640 or the digital-to-analog converter 640' can respectively adopt a high-precision and high-sampling rate ADC or DAC module, and can support conventional analog signal formats such as I_P / I_N / Q_P / Q_N; or I / Q single-ended; or single-channel. The analog-to-digital converter 640 can convert the corresponding analog signal into a digital signal. The digital-to-analog converter 640' is configured to convert the signal processed by the core processor 650 into an analog signal.

[0044] According to one embodiment, the signal processing device 60 may further include an analog-to-digital converter 640", which may also include a high-precision and high-sampling rate ADC, whose input end is configured to receive a frequency-converted RF feedback signal, and whose output end is coupled to the input end of the core processor 650, thereby forming a feedback observation channel, which can collect observation point data of the target and observe external data in real time, so that the signal processing device 60 calculates the corresponding parameters. The feedback observation channel can greatly improve the tracking performance of the system, allowing the signal processing device 60 to handle external scenarios such as rapid temperature drop, temperature rise, impedance change, etc.

[0045] According to an embodiment, the core processor 650 may have functions such as image correction (QEC), digital pre-distortion (PD), clipping processing (CFR), digital filtering (FIR), signal rate conversion (Resample), and direct current offset correction (DC-Offset EQ).

[0046] According to one embodiment, the CFR functional structure in the core processor 650 can perform the following operations: Clipping and peak suppression (Crest Factor Reduction, CFR) technology is a method for reducing signal peaks to improve power amplifier (PA) efficiency and reduce signal distortion. By monitoring the amplitude of the input signal, the peak part exceeding the set threshold is detected; the peak part exceeding the threshold is clipped to limit its amplitude to the set maximum value; filtering or other technologies are used to restore the signal quality and reduce the negative impact of clipping. The input signal can be a digital signal from the analog-to-digital converter 640.

[0047] According to an embodiment, the EQ function structure in the core processor 650 is mainly used to compensate for the distortion and interference introduced in the channel, so as to restore the original signal. The purpose of the equalization filter is to reverse the influence of the channel on the signal.

[0048] According to one embodiment, the compensation module in the core processor 650 is configured to implement a mirror image correction (QEC) function to compensate for the IQ mirror image problem caused by the inconsistency of the IQ signal link. The IQ mirror image existing within the zero intermediate frequency signal bandwidth will have a great impact on the EVM performance of the entire system, and the mirror image correction can reduce it to below the system EVM index.

[0049] According to one embodiment, the pre-distortion function structure in the core processor 650 is a function implemented in the digital domain, and its function is to introduce distortion opposite to the nonlinear characteristics of the power amplifier. After the output signal of the signal processing device after PD processing passes through the power amplifier, it can just balance the distortion generated by the power amplifier, so that the signal output by the RF signal processing system can be restored to linearity.

[0050] According to an embodiment, the FIR functional structure in the core processor 650 can provide LPF filtering with a transition band <10Mhz suppression degree> 40dbc, which is more than 10 times better than the traditional analog LPF.

[0051] The signal processing device proposed in the present application has an enhancement algorithm for improving the performance and linearity of the power amplifier. The adaptability of the signal processing device is improved by using the analog-to-digital conversion and digital-to-analog conversion units before and after the core processing unit and the feedback analog-to-digital conversion unit. The application scenarios of the signal processing device are expanded by using high-bandwidth and high-linearity analog switches. The device has stronger adaptability and compatibility, thereby lowering the application threshold of the RF enhancement technology and reducing the cost of the system.

[0052] Figure 7 Shown is a module schematic diagram of an existing WiFi router. Figure 7 The WiFi router shown includes a baseband module 70, a radio frequency module 71, and a radio frequency front-end module 72, wherein the radio frequency front-end module 72 includes a power amplifier unit. In some embodiments, the baseband module 70 and the radio frequency module 71 are located in a WiFi chip set, and can be integrated or separated.

[0053] The power amplifier units used in current WiFi routers focus on linearity and output bandwidth but sacrifice efficiency and output power. As a result, in high modulation scenarios (1024QAM and 4096QAM), the output power cannot meet the requirements, resulting in insufficient coverage area and excessive heat generation at high throughput. Currently, WiFi chip solution providers provide some signal processing and power amplifier linearization functions, but these functions are currently integrated into the baseband module and have limited performance, which cannot meet the purpose of increasing output power to significantly increase coverage area at high throughput.

[0054] Figure 8 The figure shows a module schematic diagram of a WiFi router according to an embodiment of the present application. As shown in the figure, the RF interface signal processing module 80 can be coupled between the WiFi chip set 81 and the RF front-end module 82, wherein the RF module is located in the WiFi chip set 81, and the power amplifier units 8210 to 821n are located in the RF front-end module 82. While solving the RF performance of the WiFi router, this embodiment does not need to separate the baseband module from the RF module.

[0055] According to one embodiment, the system supports N channels, where N is an integer greater than or equal to 1. The frequencies of signals in different channels may be different. The RF transmission interfaces 8110 to 811n in the WiFi chip set 81 are coupled to the down-conversion units 810 to 81n in the RF interface signal processing module 80, and the signals output by the down-conversion units are provided to the signal processing device 860 and converted into digital signals through its analog-to-digital converter for, for example, pre-distortion processing.

[0056] According to one embodiment, the signal processing device 860 (such as the aforementioned embodiment) can provide pre-distortion processing functions, as well as frequency response equalization (EQ), clipping processing (CFR), orthogonal imbalance calibration (QE), local oscillator leakage calibration (LOL), filter, power statistics and the like.

[0057] According to one embodiment, since the WiFi signal has very high requirements for EVM, in order to reduce the impact of the additional down-conversion and up-conversion units on the WiFi set 81 on the EVM, the up and down conversion units of the same channel need to use the same high-frequency clock subunit to provide the local oscillator signal, for example, the up and down conversion units use the same high-frequency clock. In addition, when the high-frequency clock is 1MHz or above, the point frequency phase noise needs to be as small as possible. When the frequency of the high-frequency clock is lower than 1MHz, the phase noise requirement is relatively low. The high-frequency clock subunits 830 to 83n used in different channels can be the same or different clock sources depending on application requirements.

[0058] In one embodiment of the present application, the down-conversion unit 810 and the up-conversion unit 820 are in the same channel and can jointly receive the local oscillator signal from the high-frequency clock subunit 830. The down-conversion unit 81n and the up-conversion unit 82n are in the same channel and can jointly receive the local oscillator signal from the high-frequency clock subunit 83n.

[0059] According to one embodiment, if real-time tracking of RF performance is required, couplers 8220 to 822n or power dividers need to be provided at the output ends of the power amplifier units 8210 to 821n in the RF front-end module 82. The output ends of the couplers 8220 to 822n can be electrically connected to the input end of the feedback selection switch 850 for selecting the feedback channel that the RF interface signal processing module currently needs to observe. According to other embodiments, the signals fed back to the feedback selection switch 850 by the couplers 8220 and 822n can have different frequencies.

[0060] According to one embodiment, the output end of the feedback selection switch 850 is electrically connected to the down-conversion subunit 870, and the RF feedback signal is transferred to the baseband and provided to the signal processing device 860 for real-time observation of the RF feedback signal, calculation and real-time adjustment of the output signal of the RF interface signal processing module.

[0061] According to one embodiment, the down-conversion subunit 870 requires a high-frequency clock source to provide a local oscillator. If there are multiple high-frequency clock subunits in the system, such as high-frequency clock subunits 830 to 83n, multiple clocks need to be selected by the clock switching switch 840 before they can be given to the down-conversion subunit 870 as a local oscillator input. The selection of the clock switching switch is related to the RF feedback signal to be monitored.

[0062] According to one embodiment, in the feedback channel, the clock switching switch 840 is configured to select the local oscillator signal generated by the high-frequency clock subunit 830 or 83n based on the RF feedback signal to be observed, and select the same high-frequency clock source as the transmission link currently to be monitored. For example, to monitor the RF signal of the channel where the coupler 8220 is located, it is necessary to select the same high-frequency clock source as the up-conversion unit 810 and the down-conversion unit 820, that is, the high-frequency clock subunit 830. The high-frequency clock subunits 830 to 83n do not need to share the reference signal with the WiFi chip set 81.

[0063] According to one embodiment, the down-conversion subunit 870 is configured to apply the local oscillator signal provided by the clock switching switch 840 to the signal output by the feedback selection switch 850, thereby down-converting the RF feedback signal to baseband.

[0064] According to one embodiment, the LNAs 8240 to 824n of the RF front-end module 82 are electrically connected to the RF receiving interfaces 8120 to 812n of the WiFi chip set 81. The RF receiving interfaces 8120 to 812n of the WiFi chip set 81 are configured to receive RF receiving signals from the LNAs 8240 to 824n.

[0065] Fig. 9 The figure shows a module schematic diagram of an existing base station. As can be seen from the figure, the FPGA processing unit 921 is responsible for processing the digital signal generated by the base station. The base station shown in the figure includes a baseband module 91, an intermediate frequency processing module 92, a radio frequency module 93 and a radio frequency front-end module 94. The intermediate frequency processing module 92 includes an FPGA processing unit 921 with signal processing capabilities. This solution requires high resources and performance of the FPGA processing unit 921 because it needs to realize functions such as digital pre-distortion, thereby greatly increasing the system cost, system power consumption and design cost.

[0066] Fig.10 The module schematic diagram of another existing base station is shown. The base station shown in the figure includes a baseband module 101, an intermediate frequency processing module 102, a highly integrated radio frequency module 103 and a radio frequency front-end module 104. As can be seen from the figure, the FPGA processing unit 1022 and the digital signal processing unit 1031 in the highly integrated radio frequency module 103 are jointly responsible for processing the digital signal generated by the base station. However, a high-speed digital interface must be used between the intermediate frequency processing module 102 and the highly integrated radio frequency module 103, and the cost of this interface is very high. In addition, the signal processing capability of the highly integrated radio frequency module cannot be guaranteed.

[0067] In some embodiments, the RF interface signal processing module proposed in the present application may be located at, for example, Fig. 9The RF interface signal processing module is configured to receive signals from the RF module and the RF front-end module. The input and output signals of the RF interface signal processing module are RF signals.

[0068] In some embodiments, the RF interface signal processing module proposed in the present application may be located at, for example, Fig.10 The medium-to-high-integration RF module 103 and the RF front-end module 104 are configured to receive signals from the high-integration RF module and the RF front-end module to implement, for example, pre-distortion operations.

[0069] In some other applications, the RF interface signal processing module proposed in this application can also be used in the base station repeater scenario to observe the signal output by the power amplifier unit in the RF front-end module in real time, calculate and adjust the output signal of the RF interface signal processing module in real time.

[0070] According to different embodiments of the present application, the above-mentioned signal processing device or radio frequency interface signal processing module can be used in different communication devices, such as base stations, drones, mobile phones, walkie-talkies, cars, satellites, or wireless cameras, etc., and can reduce product costs while realizing digital enhancement processing functions.

[0071] The RF interface signal processing module is used to convert the RF feedback signal output by the RF front-end module and the RF signal output by the RF module to baseband, and provide them to the signal processing device in the RF interface signal processing module for pre-distortion operation, and up-convert the processed signal to the frequency point where the RF transmission signal is located.

[0072] The RF interface signal processing module proposed in this application can be directly applied between the RF module and the RF front-end module without changing the original Wifi router or base station framework. There is no need to change the RF module, so as to improve the linearity of the RF signal output by the power amplifier, thereby lowering the application threshold of RF enhancement technology and reducing the cost of baseband chips or RF chips.

[0073] The above embodiments are only used to illustrate the present invention, but not to limit the present invention. Ordinary technicians in the relevant technical field can make various changes and modifications without departing from the scope of the present invention. Therefore, all equivalent technical solutions should also fall within the scope of the present invention.

Claims

1. A communication system, comprising: Baseband module, RF module, and RF front-end module; and, a radio frequency interface signal processing module coupled between the radio frequency module and the radio frequency front-end module; The RF interface processing module is configured to at least receive a first RF signal from the RF module; The RF interface signal processing module includes a signal processing device, and the signal processing device is configured to perform a digital predistortion operation based on at least the first RF signal, thereby obtaining a second RF signal with digital predistortion information.

2. The system according to claim 1, wherein: The radio frequency interface signal processing module includes: a down-conversion unit, configured to receive the first radio frequency signal and perform a down-conversion operation to obtain the first analog signal; an up-conversion unit, configured to perform an up-conversion operation on the second analog signal generated by the signal processing device to obtain a second radio frequency signal; The signal processing device is coupled between the up-conversion unit and the down-conversion unit, and is configured to receive the first analog signal and convert it into a first digital signal, and perform digital predistortion processing on the first digital signal to obtain a second digital signal and convert it into the second analog signal.

3. According to the system of claim 2, the RF interface signal processing module also includes a feedback channel, configured to receive an RF feedback signal from the RF front-end module, convert the RF feedback signal into a third analog signal and provide it to the signal processing device.

4. The system according to claim 3, wherein: The RF interface signal processing module is also configured to receive multiple RF analog signals and RF feedback signals.

5. The system according to claim 4, wherein the feedback channel in the radio frequency interface signal processing module comprises: A feedback selection switch, coupled to the RF front-end module, configured to select and output multiple RF feedback signals; a down-conversion subunit, configured to perform a down-conversion operation on the RF feedback signal, and provide a third analog signal generated after the frequency conversion to the signal processing device; The high frequency clock subunit is configured to generate the local oscillator signal required by the down-conversion subunit.

6. The system according to claim 5, wherein: The signal processing device comprises: a first analog-to-digital converter configured to convert the first analog signal into a first digital signal; A core processor, coupled to the first analog-to-digital converter, configured to process the first digital signal and output a second digital signal with at least digital predistortion information; A digital-to-analog converter, coupled to the core processor, is configured to convert the second digital signal into a second analog signal.

7. The system according to claim 6, wherein: The signal processing device further includes a second analog-to-digital converter coupled to the core processor and configured to receive the third analog signal, convert the third analog signal into a third digital signal, and provide the third digital signal to the core processor.

8. The system according to claim 7, wherein: The signal processing device obtains a second radio frequency signal with predistortion information based on the first radio frequency signal and the radio frequency feedback signal.

9. The system according to claim 8, wherein: The system is a wifi router, wherein the radio frequency interface signal processing module further includes a clock selection switch configured to select local oscillator signals generated by a plurality of high-frequency clock subunits.

10. The communication system according to any one of claims 1-9, wherein the communication system further comprises a base station, a drone, a mobile phone, a walkie-talkie, a car, a satellite, or a wireless camera.

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