A radio frequency circuit, a signal feedback circuit and a communication system

Abstract

A radio frequency circuit, a signal feedback circuit and a communication system are used to configure a signal feedback path for the communication system. The radio frequency circuit comprises at least one radio frequency transmitting channel and a radio frequency circuit; the at least one radio frequency transmitting channel is connected with at least one PA, and the at least one PA is connected with at least one envelope tracking (ET) circuit used to supply power for the at least one PA; a first input end of the signal feedback circuit is used to be connected with an output end of the at least one PA, a second input end of the signal feedback circuit is used to be connected with an output end of the at least one ET circuit, and the signal feedback circuit is used to feedback an output signal of the at least one PA and a signal output by the at least one ET circuit and output through an output end of the signal feedback circuit.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wireless communication, in particular to a radio frequency circuit, a signal feedback circuit and a communication system. BACKGROUND

[0002] The power amplifier (PA) is a key device in the transmission link of modern communication systems. Its main function is to amplify the small power signal processed by the front-end circuit to the rated power level specified by the communication system standard, and then feed it into the back-end devices such as duplexers and antennas for wireless transmission.

[0003] During the operation of the PA, in order to ensure the amplification efficiency of the PA, it is required to work in the signal saturation interval. In actual application, due to the production and manufacturing problems of the PA device, the gain curve of the PA will be nonlinear, and the nonlinearity of the PA gain curve will directly reduce the signal transmission quality and affect the adjacent frequency band system.

[0004] In order to combat the nonlinearity of the PA, the digital pre-distortion (DPD) technology was proposed in the 1990s and widely applied in various wireless communication systems, including access network base stations and user terminals. The working principle of DPD is very simple, that is, through the DPD core, the gain nonlinearity of the PA is fitted, and then the inverse function of the PA distortion characteristic is obtained, and the appropriate pre-distortion parameters of the DPD core are configured according to the inverse function to compensate the transmission signal. The small power signal output by the front-end circuit will pass through two nonlinear devices with opposite characteristics, the DPD core and the PA, and their distortion characteristics will cancel each other out, thereby obtaining the final linear PA transmission characteristic.

[0005] With the development of wireless communication systems, in order to reduce the amplification loss of the PA, the envelope tracking (ET) technology is proposed. The ET technology is a technology that modulates the supply port or bias port of the PA according to the amplitude of the PA input signal to reduce the PA amplification loss, which improves the energy conversion efficiency of the PA. Therefore, its power consumption can be greatly reduced in theory, and the energy conversion efficiency of the radio frequency front-end is significantly improved. ET-PA is also considered by the industry as one of the important features of 5G terminal side.

[0006] At present, the existing ET design is designed for 3G and long term evolution (LTE) technology. Since the signal transmission bandwidth of 3G and LTE is limited, when the PA is applied to the large bandwidth application scenario of 5G, nonlinearity will also occur in the ET, which will directly affect the signal transmission quality of the PA. SUMMARY

[0007] The present application provides a radio frequency circuit, a signal feedback circuit and a communication system, which are configured to configure a signal feedback path for a communication system to improve signal transmission quality of the communication system.

[0008] It should be understood that in the scheme provided by the embodiments of the present application, the communication system can be a wireless communication device, or a part of the wireless communication device, such as a system chip or a communication chip, and the like integrated circuit products. The wireless communication device can be a computer device supporting wireless communication function.

[0009] Specifically, the wireless communication device can be a terminal such as a smart phone, or a wireless access network device such as a base station. The system chip can also be referred to as a system on chip (SoC), or simply SoC chip. The communication chip can include a baseband processing chip and a radio frequency processing chip. The baseband processing chip is also sometimes referred to as a modem or a baseband chip. The radio frequency processing chip is also sometimes referred to as a radio frequency transceiver or a radio frequency chip. In physical implementation, part or all of the chips in the communication chip can be integrated inside the SoC chip. For example, the baseband processing chip is integrated in the SoC chip, and the radio frequency processing chip is not integrated with the SoC chip.

[0010] In a first aspect, the embodiments of the present application provide a radio frequency circuit, which includes at least one radio frequency transmission channel and a signal feedback circuit.

[0011] Specifically, the at least one radio frequency transmission channel is connected with at least one PA, and the at least one PA is connected with at least one envelope tracking (ET) circuit for supplying power to the at least one PA; a first input end of the signal feedback circuit is used to be connected with an output end of the at least one PA, a second input end of the signal feedback circuit is used to be connected with an output end of the at least one ET circuit, and the signal feedback circuit is used to feedback an output signal of the at least one PA and an output signal of the at least one power supply circuit and output through an output end of the signal feedback circuit.

[0012] With the above scheme, the signal transmitted in the at least one radio frequency transmission channel is transmitted through the at least one PA. In order to reduce the non-linear distortion of the output signal of the at least one PA, the output signal of the at least one PA causing the non-linear distortion of the output signal and the output signal of the at least one ET circuit are fed back to the front-end device. The front-end device can adjust the signal based on the feedback signal to reduce the non-linear distortion of the output signal of the at least one radio frequency transmission channel and ensure the quality of the output signal of the at least one PA.

[0013] In a possible design, the signal feedback circuit includes: a feedback circuit and an analog-to-digital conversion circuit.

[0014] Specifically, a first input terminal of the feedback circuit is configured to be connected to an output terminal of the at least one PA, a second input terminal of the feedback circuit is configured to be connected to an output terminal of the at least one ET circuit, and an output terminal of the feedback circuit is connected to an input terminal of the analog-to-digital conversion circuit; and the analog-to-digital conversion circuit is configured to perform analog-to-digital conversion on a signal output by the feedback circuit and output the signal through an output terminal of the analog-to-digital conversion circuit.

[0015] By using the above scheme, the analog signal output by the at least one PA and the analog signal output by the at least one ET circuit can be fed back, and the fed-back analog signals can be converted into digital signals that can be directly processed by a backend device by using the analog-to-digital conversion circuit.

[0016] In a possible design, the signal feedback circuit includes: a first coupler corresponding to the at least one PA and a second coupler corresponding to the at least one ET circuit.

[0017] Specifically, each first coupler is connected to an output terminal of a corresponding PA, and each first coupler is configured to feed back an output signal of the connected PA; and each second coupler is connected to an output terminal of a corresponding power supply circuit, and each second coupler is configured to feed back an output signal of the connected ET circuit.

[0018] By using the above scheme, in order to ensure the signal quality output by each PA, the first coupler and the second coupler are used to feed back the output signal of each PA connected to the radio frequency circuit and the output signal of each ET circuit.

[0019] In a possible design, a first input terminal of the feedback circuit is connected to an output terminal of the at least one PA through at least one third coupler, and a second input terminal of the feedback circuit is connected to an output terminal of the at least one ET circuit through at least one fourth coupler; and the at least third coupler corresponds to the at least one PA in a one-to-one manner, and the at least one fourth coupler corresponds to the at least one ET circuit in a one-to-one manner.

[0020] In a possible design, the radio frequency circuit includes a plurality of radio frequency transmission channels, the at least one PA is connected to the plurality of radio frequency transmission channels in a one-to-one manner, and the signal feedback circuit further includes: a selection circuit.

[0021] Specifically, the feedback circuit is connected to the analog-to-digital conversion circuit through the selection circuit, and the selection circuit is configured to sequentially output signals output by the feedback circuit according to a pre-set output sequence.

[0022] With the above scheme, since the RF channel is connected to multiple PAs and multiple PAs are connected to multiple ET circuits, there are multiple signals fed back by the feedback circuit. In order to reduce the area of ​​the RF circuit, a circuit can be selected to output the signals fed back by the feedback circuit to the analog-to-digital converter circuit for analog-to-digital conversion in sequence, thereby reducing the area of ​​the RF circuit occupied by setting multiple analog-to-digital converter circuits.

[0023] In one possible design, the analog-to-digital conversion circuit includes: a filter corresponding to each PA and an analog-to-digital converter corresponding to each filter.

[0024] Specifically, the input of each filter is connected to the selection circuit. Each filter is used to receive the output signal of the corresponding PA and the output signal of the ET circuit connected to the corresponding PA, and outputs the received signal to the connected analog-to-digital converter after filtering. Each analog-to-digital converter is used to receive the signal output by the connected filter and perform analog-to-digital conversion on the received signal.

[0025] In one possible design, the feedback circuit also includes a combiner corresponding to each PA.

[0026] Specifically, the first input terminal of each combiner is connected to the output terminal of the first coupler connected to the corresponding PA, the second input terminal of each combiner is connected to the output terminal of the second coupler connected to the ET circuit used to power the corresponding PA, the output terminal of each combiner is connected to the analog-to-digital conversion circuit, and each combiner is used to combine the signals output by the connected first coupler and second coupler into one signal and output it to the converter.

[0027] By adopting the above scheme, two feedback signals can be combined into one signal using a combiner, reducing the number of ports in the selection circuit. While ensuring the transmission of complete feedback signals, this also helps to reduce the size of the signal feedback circuit.

[0028] In one possible design, the signal feedback circuit also includes a processor.

[0029] Specifically, the processor is connected to the analog-to-digital converter circuit. The processor is used to receive the signal output by the analog-to-digital converter circuit and output a signal for adjusting the received signal of the radio frequency circuit and the output signal of at least one ET circuit.

[0030] Using the above scheme, the processor processes the signal output by the analog-to-digital converter, determines the nonlinear distortion of the PA output signal based on the signal output by the analog-to-digital converter, and adjusts the signals received by the RF circuit and the output signals of at least one ET circuit to compensate for nonlinear distortion based on the nonlinear distortion of the PA output signal.

[0031] In one possible design, the input of each RF transmit channel is connected to a first digital predistortion (DPD) core, and the ET circuit used to power the PA connected to each RF transmit channel includes a second DPD core.

[0032] Secondly, embodiments of this application provide a signal feedback circuit applied in a communication system, the communication system including a radio frequency circuit, at least one power amplifier connected to the radio frequency circuit, and an envelope tracking ET circuit connected to at least one PA for powering the connected PA.

[0033] Specifically, the first input terminal of the signal feedback circuit is used to connect to the output terminal of at least one PA, the second input terminal of the signal feedback circuit is used to connect to the output terminal of at least one ET circuit, and the signal feedback circuit is used to feed back the output signal of at least one PA and the signal output by at least one ET circuit and output them through the output terminal of the signal feedback circuit.

[0034] Using the above scheme, the signal transmitted in the radio frequency circuit is transmitted through at least one PA. In order to reduce the nonlinear distortion of the PA output signal, the output signal of at least one PA that causes the nonlinear distortion of the output signal and the output signal of at least one power supply circuit can be fed back to the front-end device. The front-end device can adjust the signal based on the feedback signal to reduce the nonlinear distortion of the signal output by at least one radio frequency transmission channel and ensure the quality of the output signal of at least one PA.

[0035] In one possible design, the signal feedback circuit includes a feedback circuit and an analog-to-digital converter circuit.

[0036] Specifically, the first input terminal of the feedback circuit is used to connect to the output terminal of at least one PA, the second input terminal of the feedback circuit is used to connect to the output terminal of at least one ET circuit, and the output terminal of the feedback circuit is connected to the input terminal of the analog-to-digital converter circuit; the analog-to-digital converter circuit is used to perform analog-to-digital conversion processing on the signal output by the feedback circuit and output it through the output terminal of the analog-to-digital converter.

[0037] In one possible design, each feedback module includes: a signal feedback circuit including: a first coupler corresponding to at least one PA and a second coupler corresponding to at least one ET circuit.

[0038] Specifically, each first coupler is connected to the output terminal of the corresponding PA, and each first coupler is used to feedback the output signal of the connected PA; each second coupler is connected to the output terminal of the corresponding ET circuit, and each second coupler is used to feedback the output signal of the connected ET circuit.

[0039] In one possible design, the RF circuit includes multiple RF transmission channels, and at least one PA is connected to each of the multiple RF transmission channels in a one-to-one correspondence. The signal feedback circuit also includes a selection circuit.

[0040] Specifically, the feedback circuit is connected to the analog-to-digital converter circuit through a selection circuit. The selection circuit is used to output the signals output by the feedback circuit in sequence according to a preset output order.

[0041] In one possible design, the analog-to-digital conversion circuit includes: a filter corresponding to each PA and an analog-to-digital converter corresponding to each filter.

[0042] Specifically, the input of each filter is connected to the selection circuit. Each filter is used to receive the output signal of the corresponding PA and the output signal of the ET circuit connected to the corresponding PA, and outputs the received signal to the connected analog-to-digital converter after filtering. Each analog-to-digital converter is used to receive the signal output by the connected filter and perform analog-to-digital conversion on the received signal.

[0043] In one possible design, the feedback circuit also includes a combiner corresponding to each PA.

[0044] Specifically, the first input terminal of each combiner is connected to the output terminal of the first coupler connected to the corresponding PA, the second input terminal of each combiner is connected to the output terminal of the second coupler connected to the ET circuit used to power the corresponding PA, the output terminal of each combiner is connected to the analog-to-digital conversion circuit, and each combiner is used to combine the signals output by the connected first coupler and second coupler into one signal and output it to the converter.

[0045] In one possible design, the first input terminal of the feedback circuit is connected to the output terminal of at least one PA via at least one third coupler, and the second input terminal of the feedback circuit is connected to the output terminal of at least one ET circuit via at least one fourth coupler. Specifically, at least one third coupler corresponds one-to-one with at least one PA, and at least one fourth coupler corresponds one-to-one with at least one ET circuit.

[0046] In one possible design, the signal feedback circuit also includes a processor.

[0047] Specifically, the processor is connected to the analog-to-digital converter circuit. The processor is used to receive the signal output by the analog-to-digital converter circuit and output a signal for adjusting the received signal of the radio frequency circuit and the output signal of at least one ET circuit.

[0048] In one possible design, the RF circuit connected to at least one PA is connected to at least one first digital predistortion (DPD) core, and each ET circuit connected to the signal feedback circuit includes a second DPD core.

[0049] Thirdly, embodiments of this application provide a communication system that may include a baseband subsystem, a radio frequency circuit connected to the baseband subsystem, at least one PA connected to the radio frequency circuit, at least one ET circuit connected to the at least one PA, each ET for supplying power to the connected PA, an antenna connected one-to-one with the at least one PA, and a signal feedback circuit provided in the second aspect of this application and any possible design connected to the at least one PA and the at least one ET circuit.

[0050] By adopting the above-described communication system architecture, the signal feedback circuit provided in the second aspect and any possible design can be used to configure a signal feedback circuit in a communication system with dual DPD cores. The signal feedback circuit can be used to compensate for the nonlinear distortion of the PA output signal by the radio frequency signal, thereby ensuring the signal quality of the communication system transmission.

[0051] In one possible design, the signal feedback circuit is fixedly connected to multiple radio frequency signal transmitting circuits. Attached Figure Description

[0052] Figure 1 This application provides a schematic diagram of the structure of a wireless communication system according to an embodiment of the present application.

[0053] Figure 2 A schematic diagram of a communication system structure provided in this application embodiment. Figure 1 ;

[0054] Figure 3 A schematic diagram of a communication system structure provided in this application embodiment. Figure 2 ;

[0055] Figure 4 This is a schematic diagram of a signal feedback circuit provided in an embodiment of this application;

[0056] Figure 5 A schematic diagram of the circuit structure of a signal feedback circuit provided in an embodiment of this application. Figure 1 ;

[0057] Figure 6 A schematic diagram of the circuit structure of a signal feedback circuit provided in an embodiment of this application. Figure 2 ;

[0058] Figure 7 A schematic diagram of the circuit structure of a signal feedback circuit provided in an embodiment of this application. Figure 3 ;

[0059] Figure 8 A schematic diagram of the output signal voltage waveform of a feedback module provided in an embodiment of this application;

[0060] Figure 9 This is a schematic diagram of another feedback circuit output signal voltage waveform provided in an embodiment of this application;

[0061] Figure 10 A schematic diagram of the circuit structure of a signal feedback circuit provided in an embodiment of this application. Figure 4 ;

[0062] Figure 11 This is a schematic diagram of the structure of a radio frequency circuit provided in an embodiment of this application;

[0063] Figure 12 This is a schematic diagram of the structure of a communication system provided in an embodiment of this application. Detailed Implementation

[0064] The embodiments of this application will now be described in further detail with reference to the accompanying drawings.

[0065] The technical solutions of this application can be applied to various communication systems, such as Long Term Evolution (LTE) systems, LTE Frequency Division Duplex (FDD) systems, LTE Time Division Duplex (TDD) systems, 5th Generation (5G) systems, or New Radio (NR) systems, etc., without limitation.

[0066] The technical solutions provided in this application will be further described below with reference to the accompanying drawings and embodiments. It should be understood that the system structures and business scenarios provided in the embodiments of this application are mainly for explaining some possible implementations of the technical solutions of this application and should not be construed as a unique limitation on the technical solutions of this application. Those skilled in the art will recognize that, with the evolution of the system and the emergence of newer business scenarios, the technical solutions provided in this application will still be applicable to the same or similar technical problems.

[0067] It should be understood that the technical solutions provided in the embodiments of this application may not be repeated in the following description of specific embodiments, but it should be regarded as that there are mutual references between these specific embodiments and they can be combined with each other.

[0068] In wireless communication systems, equipment can be divided into devices that provide wireless network services and devices that use wireless network services. Devices that provide wireless network services refer to those that make up the wireless communication network; they can be simply called network equipment or network elements. Network equipment typically belongs to operators or infrastructure providers, and these vendors are responsible for its operation and maintenance. Network equipment can be further divided into radio access network (RAN) equipment and core network (CN) equipment. Typical RAN equipment includes base stations (BS).

[0069] It should be understood that a base station can sometimes be referred to as a radio access point (AP) or a transmission reception point (TRP). Specifically, a base station can be a generation Node B (gNB) in a 5G new radio (NR) system or an evolutionary Node B (eNB) in a 4G long term evolution (LTE) system. Depending on its physical form or transmit power, a base station can be classified as a macro base station or a micro base station. Micro base stations are sometimes also referred to as small base stations or small cells.

[0070] Devices using wireless network services are simply referred to as terminals. Terminals can establish connections with network devices and provide specific wireless communication services to users based on the network devices' services. It should be understood that because terminals have a closer relationship with users, they are sometimes also called user equipment (UE) or subscriber units (SU). Furthermore, unlike base stations which are typically placed in fixed locations, terminals often move with the user and are sometimes called mobile stations (MS). Additionally, some network devices, such as relay nodes (RNs) or wireless routers, can sometimes be considered terminals because they possess UE identity or belong to the user.

[0071] Specifically, the terminal can be a mobile phone, tablet computer, laptop computer, wearable device (such as smartwatch, smart bracelet, smart helmet, smart glasses), and other devices with wireless access capabilities, such as smart cars, various Internet of Things (IoT) devices, including various smart home devices (such as smart meters and smart appliances) and smart city devices (such as security or monitoring equipment, smart road traffic facilities), etc.

[0072] Figure 1 This is a schematic diagram of a communication system provided in an embodiment of this application. The communication system can be a terminal or a base station as described in this application embodiment, such as... Figure 1 As shown, the communication system may include multiple components, such as: application subsystem, memory, mass storage, baseband subsystem, radio frequency integrated circuit (RFIC), radio frequency front end (RFFE) device, and antenna (ANT). These components can be coupled through various interconnect buses or other electrical connections.

[0073] Figure 1 In this code, ANT_1 represents the first antenna, ANT_N represents the Nth antenna, and N is a positive integer greater than 1. Tx represents the transmit path, and Rx represents the receive path; different numbers represent different paths. Each path can represent a signal processing channel. FBRx represents the feedback receive path, PRx represents the main receive path, and DRx represents the diversity receive path. HB represents high frequency, and LB represents low frequency; these refer to the relative high and low frequencies. BB represents baseband. It should be understood that... Figure 3 The labels and components shown are for illustrative purposes only and represent one possible implementation. Other implementations are also included in this application. For example, the communication system may include more or fewer paths and more or fewer components.

[0074] The application subsystem can serve as the main control system or main computing system of the communication system, running the main operating system and applications, managing the hardware and software resources of the entire communication system, and providing a user interface. Furthermore, the application subsystem may also include driver software related to other subsystems (such as the baseband subsystem).

[0075] The application subsystem may include one or more processors. Multiple processors may be multiple processors of the same type, or a combination of processors of various types. In this application, the processor may be a general-purpose processor or a processor designed for a specific domain. For example, the processor may be a central processing unit (CPU), a digital signal processor (DSP), or a microcontroller (MCU). The processor may also be a graphics processing unit (GPU), an image signal processor (ISP), an audio signal processor (ASP), and an AI processor specifically designed for artificial intelligence (AI) applications. AI processors include, but are not limited to, neural network processing units (NPUs), tensor processing units (TPUs), and processors referred to as AI engines.

[0076] Figure 1 In a radio frequency (RF) subsystem, RF integrated circuits (including RFIC 1 and one or more optional RFIC 2) and RF front-end devices together constitute the RF subsystem. Depending on the signal receiving or transmitting circuitry, the RF subsystem can also be divided into an RF receive path and an RF transmit path. The RF transmit path transmits RF signals via an antenna, while the RF receive path receives RF signals via an antenna, processes these signals (e.g., amplification, filtering, and down-conversion) to obtain a baseband signal, and then transmits it to the baseband subsystem. The RF transmit path receives baseband signals from the baseband subsystem, processes them (e.g., up-conversion, amplification, and filtering) to obtain an RF signal, and finally radiates this RF signal into space via an antenna. RF integrated circuits can be referred to as RF processing chips or RF chips.

[0077] Specifically, an RF subsystem may include electronic components such as antenna switches, antenna tuners, low-noise amplifiers (LNAs), power amplifiers (PAs), mixers, local oscillators (LOs), and filters. These components can be integrated into one or more chips as needed. RF integrated circuits can be called RF processing chips or RF chips. RF front-end devices can also be standalone chips. RF chips are sometimes also referred to as receivers, transmitters, or transceivers. With technological advancements, antennas can sometimes be considered part of the RF subsystem and integrated into the RF subsystem chip. Antennas, RF front-end devices, and RF chips can all be manufactured and sold separately. Of course, the RF subsystem can also employ different devices or different integration methods based on power consumption and performance requirements. For example, some components belonging to the RF front-end can be integrated into the RF chip, or even the antenna and RF front-end devices can be integrated into the RF chip, which can also be called an RF antenna module or antenna module.

[0078] Furthermore, since radio frequency signals are typically analog signals, and the baseband subsystem primarily processes digital signals, an analog-to-digital (ADC) converter is also required in the communication system. In this embodiment, the ADC can be located in either the baseband subsystem or the radio frequency subsystem. The ADC includes an analog-to-digital converter (ADC) that converts analog signals to digital signals, and a digital-to-analog converter (DAC) that converts digital signals to analog signals.

[0079] Similar to the application subsystem, the baseband subsystem may also include one or more processors. Furthermore, the baseband subsystem may include one or more hardware accelerators (HACs). Hardware accelerators can be used to perform sub-functions with higher processing overhead, such as data packet assembly and parsing, and data packet encryption and decryption. These sub-functions can also be implemented using general-purpose processors, but due to performance or cost considerations, using hardware accelerators may be more suitable. In specific implementations, hardware accelerators are primarily implemented using application-specific integrated circuits (ASICs). Of course, hardware accelerators can also include one or more relatively simple processors, such as MCUs.

[0080] In this embodiment, the baseband subsystem and the radio frequency (RF) subsystem together constitute the communication subsystem, providing wireless communication functionality for the communication system. Typically, the baseband subsystem manages the hardware and software resources of the communication subsystem and can configure the operating parameters of the RF subsystem. The processor of the baseband subsystem can run a sub-operating system for the communication subsystem; this sub-operating system is often an embedded operating system or a real-time operating system, such as VxWorks or Qualcomm's QuRT system.

[0081] A baseband subsystem can be integrated into one or more chips, which may be called a baseband processing chip or baseband chip. Alternatively, the baseband subsystem can be a standalone chip, which may be called a modem or modem chip. Baseband subsystems can be manufactured and sold as modem chips. Modem chips are sometimes also referred to as baseband processors or mobile processors. Furthermore, the baseband subsystem can be further integrated into a larger chip, manufactured and sold as a larger chip. This larger chip may be called a system-on-a-chip (SoC), or simply a SoC chip. The software components of the baseband subsystem can be built into the chip's hardware components before the chip leaves the factory, or imported into the chip's hardware components from other non-volatile memory after the chip leaves the factory, or these software components can be downloaded and updated online via a network.

[0082] In addition, the communication system also includes a memory, for example Figure 1 The system includes main memory and large-capacity storage. Additionally, application subsystems and baseband subsystems may each include one or more caches. In specific implementations, memory can be divided into volatile memory and non-volatile memory (NVM). Volatile memory refers to memory whose data is lost when the power supply is interrupted. Currently, volatile memory is mainly random access memory (RAM), including static random access memory (SRAM) and dynamic random access memory (DRAM). Non-volatile memory refers to memory whose data is not lost even when the power supply is interrupted. Common non-volatile memories include read-only memory (ROM), optical discs, hard disks, and various memories based on flash memory technology. Generally speaking, main memory and cache can use volatile memory, while large-capacity storage can use non-volatile memory, such as flash memory.

[0083] Figure 2 This is a schematic diagram of another communication system provided in an embodiment of this application. Figure 2 This diagram illustrates some common devices used for radio frequency signal processing in communication systems. It should be understood that... Figure 2 Although only one RF receiving channel and one RF transmitting channel are shown in the illustration, the communication system in this application embodiment is not limited to this. The communication system may include one or more RF receiving channels and one or more RF transmitting channels. Each RF transmitting channel may include devices such as a DAC and a mixer. Before being transmitted through the antenna, the output signal of each RF transmitting channel undergoes power adjustment processing by a PA. The RF receiving channel may include devices such as a mixer, a filter, and an ADC. The signal received from the antenna by the RF receiving channel may also be processed by devices such as a low-noise amplifier (LNA). Figure 2 For illustrative purposes only, the devices included in the radio frequency receiving channel and radio frequency transmitting channel will not be listed one by one in the embodiments of this application.

[0084] In this embodiment of the application, the communication system further includes an ET circuit for supplying power to the PA, the ET circuit being connected to the PA for power supply. The ET circuit may include a power supply and an ET unit, the ET unit adjusting the voltage value output by the power supply to the PA according to the PA's transmitted signal.

[0085] It should be noted that the ET device is based on a single frequency point. When the communication system in this application is used in high-bandwidth application scenarios such as 5G, the existing ET device design will not be able to meet the requirements of the radio frequency subsystem and will cause signal distortion to the power supply signal sent to the PA. In order to solve this problem, the concept of setting a DPD core in the ET circuit is proposed.

[0086] Based on the preceding description, such as Figure 3 The diagram shows a possible structure of the communication system according to an embodiment of this application.

[0087] See Figure 3 The communication system may include radio frequency (RF) circuitry, which includes at least one RF transmitting channel and at least one RF receiving channel (not shown). Each RF transmitting channel includes components such as a mixer, a DAC, and a low-pass filter (LPF), and each RF receiving channel includes components such as a mixer, a DAC, and an LPF. It should be noted that... Figure 3 Although only two radio frequency transmission channels are shown, the communication system in this application embodiment is not limited to this.

[0088] In practical applications, Figure 3The communication system shown may also include other devices to transmit radio frequency signals. For example, Figure 3 In this configuration, the output of each radio frequency transmission channel is connected to a power amplifier (PA).

[0089] In practical applications, to avoid output signal distortion caused by PA manufacturing defects, the input of each RF transmission channel can be connected to a first DPD core. The first DPD core can be used to compensate for signal nonlinear distortion caused by the connected PA. The first DPD core can be located within the RF transmission channel or independent of it.

[0090] In this embodiment, each PA requires an external power supply to operate when amplifying radio frequency signals. Therefore, the voltage input terminal of the PA can also be connected to an ET circuit, meaning the ET circuit can supply power to the PA. The ET circuit can include a second DPD core, a power supply, and an ET unit. The ET unit can adjust the voltage output from the power supply to the PA based on the PA's transmitted signal. The second DPD core can be used to compensate for signal nonlinear distortion based on the power supply's output signal. In actual use, the communication system may also include other components, which will not be listed here.

[0091] In practical use, the power supply can usually only receive digital control signals and adjust the voltage value output to the PA according to the digital control signals, while the signal of the second DPD core is usually an analog signal. The ET circuit also includes a DAC connected between the second DPD core and the power supply.

[0092] Currently, existing technologies only design signal feedback paths for signal compensation of the first DPD core. For communication systems with both a first DPD core and a second DPD core, no solution has been provided for configuring the signal feedback circuit.

[0093] Based on this, embodiments of this application provide a signal feedback circuit for use in a communication system, which can be the aforementioned communication system structure, for configuring a signal feedback path for the communication system. Back-end devices can adjust the signal input to the PA based on the signal fed back by the signal feedback circuit, so as to improve the working efficiency and signal transmission quality of the communication system.

[0094] See Figure 4 As shown, in this embodiment of the application, the first input terminal of the signal feedback circuit 400 is used to connect to the output terminal of at least one PA, the second input terminal of the signal feedback circuit 400 is used to connect to the output terminal of at least one ET circuit, and the signal feedback circuit 400 is used to feed back the output signal of at least one PA and the signal output by at least one ET circuit and output them through the output terminal of the signal feedback circuit.

[0095] The signal feedback circuit 400 may include a feedback circuit 401 and an analog-to-digital conversion circuit 402.

[0096] Specifically, the first input terminal of the feedback circuit 401 is used to connect to the output terminal of at least one PA, the second input terminal of the feedback circuit 401 is used to connect to the output terminal of at least one ET circuit, and the output terminal of the feedback circuit 401 is connected to the input terminal of the analog-to-digital converter circuit. The analog-to-digital converter circuit is used to perform analog-to-digital conversion processing on the signal output by the feedback circuit and output it through the output terminal of the analog-to-digital converter.

[0097] In an alternative embodiment, the communication system further includes a baseband subsystem. The signal feedback circuit 400 provided in this application embodiment can be connected to the baseband subsystem. After receiving the signal output by the signal feedback circuit 400, the baseband subsystem outputs a signal to adjust the received signal of the radio frequency circuit and the output signal of at least one ET circuit according to the received signal.

[0098] In another alternative embodiment, the signal feedback circuit 400 provided in this application also includes a processor 403 (not shown).

[0099] Specifically, the processor 403 is connected to the analog-to-digital converter circuit 402. The processor 403 can be used to receive the signal output by the analog-to-digital converter circuit 402 and output a signal for adjusting the received signal of the radio frequency circuit and the output signal of at least one ET circuit.

[0100] In practical use, the signal feedback circuit 400 provided in this application embodiment can be located in the radio frequency circuit or can be independent of the radio frequency circuit. When the signal feedback circuit 400 is independent of the radio frequency circuit, the signal feedback circuit 400 and at least one PA and at least one ET circuit can be connected through a data transmission line and an interface provided on the signal feedback circuit 400.

[0101] The specific structures of the feedback circuit 401, analog-to-digital conversion circuit 202, and processor 203 in the signal feedback circuit 400 are described below.

[0102] I. Feedback Circuit 401

[0103] The first input terminal of the feedback circuit 401 is used to connect to the output terminal of at least one PA, the second input terminal of the feedback circuit 401 is used to connect to the output terminal of at least one ET circuit, and the output terminal of the feedback circuit 401 is connected to the input terminal of the analog-to-digital converter circuit 402.

[0104] The feedback circuit 401 includes a first coupler corresponding to at least one PA and a second coupler corresponding to at least one ET circuit.

[0105] Specifically, the input terminal of each first coupler is connected to the output terminal of the corresponding PA, and each first coupler is used to feedback the output signal of the connected PA; the input terminal of each second coupler is connected to the output terminal of the corresponding ET circuit, and each second coupler is used to feedback the output signal of the connected ET circuit.

[0106] Optionally, the feedback circuit 401 may further include a combiner corresponding to each PA. The first input terminal of each combiner is connected to the output terminal of a first coupler connected to the corresponding PA, the second input terminal of each combiner is connected to the output terminal of a second coupler connected to an ET circuit used to power the corresponding PA, and the output terminal of each combiner is connected to the analog-to-digital converter 402. Each combiner is used to combine the signals output from the connected first and second couplers into a single signal and output it to the analog-to-digital converter 402.

[0107] In one possible implementation, the first input terminal of the feedback circuit 401 is connected to the output terminal of at least one PA via at least one third coupler, and the second input terminal of the feedback circuit 401 is connected to the output terminal of at least one ET circuit via at least one fourth coupler. Specifically, at least one third coupler corresponds one-to-one with at least one PA, and at least one fourth coupler corresponds one-to-one with at least one ET circuit.

[0108] It should be noted that the feedback circuit 401 is connected to the output terminal of PA through the third coupler and to the output terminal of ET circuit through the fourth coupler. Therefore, the area used to set the first coupler and the second coupler in the feedback circuit is reduced, and the cost and volume of the signal feedback circuit 400 are reduced.

[0109] II. Analog-to-Digital Conversion Circuit 402

[0110] The analog-to-digital converter (ADC) 402 is connected to the output of the feedback circuit 401. The ADC 402 performs analog-to-digital conversion on the signal output from the feedback circuit 401 and outputs it through the ADC's output terminal. This includes a filter corresponding to each PA and an ADC corresponding to each filter. The filter can be an LPF (Low-Power Factor).

[0111] Specifically, the input terminal of each LPF is connected to the feedback circuit 401. Each LPF is used to receive the output signal of the corresponding PA and the output signal of the ET circuit connected to the corresponding PA, and outputs the received signal to the connected ADC after filtering. Each ADC is used to receive the signal output by the connected filter and perform analog-to-digital conversion on the received signal.

[0112] In one example, to reduce the size of the signal feedback circuit 400, the analog-to-digital converter circuit 402 may include an LPF and an ADC.

[0113] In actual use, the communication system includes multiple PAs and ET circuits connected one-to-one with each PA. Therefore, the feedback circuit 401 outputs the output signals of multiple PAs and the output signals of multiple ET circuits. Since the ADC and LPF can only process one signal at a time, the signal feedback circuit 400 provided in this embodiment also includes a selection circuit 404 (not shown). The feedback circuit 401 can be connected to the analog-to-digital conversion circuit 402 through the selection circuit 404. The selection circuit 404 is used to output the signals output by the feedback circuit 401 in sequence according to a preset output order. The LPF and ADC then process the received signals after receiving the signals output by the selection circuit 404.

[0114] III. Processor 403

[0115] The processor 403 is connected to the analog-to-digital converter circuit 402. The processor 403 is used to receive the signal output by the analog-to-digital converter circuit 402 after analog-to-digital conversion, and to output signals for adjusting the received signal of the radio frequency circuit and the output signal of at least one ET circuit.

[0116] In a specific implementation, the processor 403 can store the correspondence between feedback signals and predistortion parameters. After receiving the feedback signal after analog-to-digital conversion from the ADC output, the processor 403 determines the target RF transmission channel corresponding to the received feedback signal. Based on the stored correspondence between feedback signals and predistortion parameters, the processor 403 determines the predistortion parameters corresponding to the feedback signal and outputs the predistortion parameters to the first DPD core connected to the target transmission channel and the second DPD core in the ET circuit that powers the PA connected to the target transmission channel. After receiving the predistortion parameters, the first DPD core and the second DPD core adjust the signal output by the ET circuit and the signal output to the RF circuit to compensate for the nonlinear distortion generated by the PA and the nonlinear distortion generated by the ET circuit. This adjusts the signal received by the RF circuit and the signal output by at least one ET circuit, thereby improving the signal quality of the communication system transmission.

[0117] In practice, the ADC outputs the output signals of multiple PAs and multiple ET circuits in the communication system in a pre-set order. Based on the order of the ADC output signals, the signal received by the processor 403 is determined as the source of the signal, and the target transmission channel is determined based on the source of the signal.

[0118] In one example, when the signal output by the ADC is the output signal of the PA connected to the target RF transmission channel, the processor, after determining the predistortion parameters, outputs the predistortion parameters to the first DPD core connected to the target RF transmission channel.

[0119] For example, the feedback signal includes at least frequency and amplitude, and the correspondence between the feedback signal and the predistortion parameters is shown in Table 1 below:

[0120] Table 1

[0121] Frequency Amplitude Predistortion parameter X1 Y1 Z1 X2 Y2 Z2 X3 Y3 Z3 X4 Y4 Z4

[0122] As shown in Table 1, when the processor 403 receives the feedback signal from the ADC output, it uses the amplitude and frequency included in the feedback signal from the ADC output to find the corresponding predistortion parameter, and outputs the predistortion parameter to the corresponding DPD core.

[0123] Using the structure of the signal feedback circuit 400 described above, the feedback circuit feeds back signals from multiple PAs connected to the communication system and the RF circuit, as well as signals from multiple ET circuits that power the PAs. After processing by an ADC, the signal is output to the processor 403. The processor 403 can configure preset parameters based on the stored correspondence between the feedback signal and the predistortion parameters, and outputs the configured predistortion parameters to the first DPD core and the second DPD core. In this scheme, a signal feedback circuit can be configured for a communication system with dual DPD cores, and appropriate predistortion parameters can be configured for the dual DPD cores by the processor, ensuring the signal quality of the transmitted signals in the communication system.

[0124] The processor 403 can be a CPU, DSP, or MCU.

[0125] It should be noted that the above description of the structure of feedback circuit 401, analog-to-digital conversion circuit 402 and processor 403 is only an example. In actual applications, feedback circuit 401, analog-to-digital conversion circuit 402 and processor 403 can also adopt other structures, and this application embodiment does not limit them.

[0126] In specific implementation, depending on the different components included in the signal feedback circuit 401, the signal feedback circuit 400 in this application embodiment can be divided into four specific circuit structures. The structure of the signal feedback circuit 400 provided in this application will be described below with reference to the embodiments, and can specifically include the following four schemes:

[0127] The specific structure of the signal feedback circuit 400 provided in this application will be described in detail below with reference to the embodiments.

[0128] Example 1

[0129] likeFigure 5 The diagram shown is a structural schematic of a signal feedback circuit 400 provided in an embodiment of this application.

[0130] The signal feedback circuit 400 includes a feedback circuit 401, an analog-to-digital conversion circuit 402, a selection circuit 404, and a processor 403.

[0131] The feedback circuit 401 includes a first coupler corresponding to at least one PA and a second coupler corresponding to at least one ET circuit. The selection circuit 404 includes a plurality of selection switches K. The analog-to-digital conversion circuit 402 includes an LPF and an ADC.

[0132] Specifically, the first coupler may include a first attenuator A1, the input of which is connected to the output of the corresponding PA. A1 can be used to attenuate the amplitude of the output signal of the connected PA and output it. The second coupler may include a second attenuator A2, the input of which is connected to the output of the corresponding ET circuit. A2 can be used to attenuate the amplitude of the output signal of the connected ET circuit and output it. K is connected to the output of each A1 and each A2 in the feedback circuit. K can be used to receive the feedback signals output by the connected A1 and A2 and output the received signals sequentially according to a preset output order. The input of the LPF is connected to the output of K, and the output of the LPF is connected to the ADC. It is used to filter the output signal of K and output it to the ADC. The ADC is connected to the processor 403. It is used to perform analog-to-digital conversion on the output signal of the LPF and output it to the processor 403. The processor 403 generates predistortion parameters according to the received signal and outputs them to the corresponding DPD core.

[0133] In a specific implementation, K may include multiple first input ports, multiple second input ports, and a first output port. Each first input port is connected to the output of each A1 in a one-to-one correspondence, each second input port is connected to the output of each A2 in a one-to-one correspondence, and the output port is connected to the analog-to-digital converter circuit 402.

[0134] In practical applications, the feedback circuit can output multiple signals. Therefore, when configuring K, a 4-to-1 K, an 8-to-1 K, a 16-to-1 K, or other types of multiplexers can be selected based on the number of PA and ET circuits in the communication system. It should be noted that the structure of the selection circuit in this embodiment is only illustrative; in actual use, other chips or devices can be selected.

[0135] It should be noted that the communication system may also include a baseband subsystem. The radio frequency (RF) circuit receives the baseband signal from the baseband subsystem and performs up-conversion and filtering on the baseband signal through the LPF and mixer in the RF transmission channel to obtain the RF signal. The power amplifier (PA) performs power adjustment processing on this RF signal. Therefore, the frequency of the PA's output signal is much higher than the frequency of the baseband signal. Consequently, the feedback signal output by A1 cannot be directly processed. When the ADC processes the PA's output signal from A2, the ADC needs to down-convert the signal output by A2 before outputting it to the back-end connection devices.

[0136] Specifically, the ADC operating frequency can switch between a first frequency and a second frequency. When the ADC processes the feedback signal output from A1, the ADC operates at the first frequency. When the ADC processes the feedback signal output from A2, the ADC operating frequency switches from the first frequency to the second frequency. Note that the first frequency is not equal to the second frequency; for example, the first frequency can be less than the second frequency.

[0137] For example, the first frequency could be 2.1 GHz; the second frequency could be 3.5 GHz. Of course, the above are just examples, and the specific values ​​of the first and second frequencies can be determined according to the actual situation, which will not be listed one by one here.

[0138] In practical implementation, the ADC can receive frequency switching control commands output by the processor or an external processor, and perform frequency switching upon receiving the control commands. The specific method of receiving the control commands and their format are not limited in this embodiment. Embodiment Two

[0139] like Figure 6 The diagram shown is a schematic representation of a signal feedback circuit provided in an embodiment of this application.

[0140] The signal feedback circuit 400 includes a feedback circuit 401, an analog-to-digital conversion circuit 402, a selection circuit 404, and a processor 403.

[0141] The feedback circuit 401 includes a first coupler corresponding to at least one PA and a second coupler corresponding to at least one ET circuit. The selection circuit 404 includes a plurality of selection switches K. The analog-to-digital conversion circuit 402 includes an LPF and an ADC.

[0142] In a specific implementation, the first coupler may include A1 and a mixer. The input of A1 is connected to the output of the corresponding PA, and the output of A2 is connected to the first input of the mixer. A1 can be used to attenuate the amplitude of the output signal of the connected PA and output it to the mixer. The second input of the mixer is connected to the input of the PA. The mixer can be used to perform frequency mixing on the signal output by A1 and output the frequency-mixed signal. The second coupler may include A2 and a mixer. The input of A2 is connected to the output of the corresponding ET circuit. A2 can be used to attenuate the amplitude of the output signal of the connected ET circuit and output it. The input of K is connected to the output of each mixer in the feedback circuit and the output of A2. K can be used to receive the signals output by the connected mixers and A2, and output the received signals in sequence according to the preset output order. The input of LPF is connected to the output of K, and the output of LPF is connected to ADC. It is used to filter the output signal of K and output it to ADC. ADC is connected to processor 403. It is used to perform analog-to-digital conversion on the output signal of LPF and output it to processor 403. Processor 406 can generate predistortion parameters according to the received signal and output the predistortion parameters to the corresponding DPD core.

[0143] It should be noted that the frequency of the feedback signal output by A1 is too high for the processor 403 to process directly. Before the signal output by A1 is sent to the ADC, a mixer is needed to down-convert the feedback signal output by A1 before it is sent to the back-end connection devices. Therefore, the ADC does not need to switch between the first and second frequencies, reducing the problems of low conversion efficiency and low conversion accuracy caused by the delay in ADC frequency switching.

[0144] In a specific implementation, the processor 403 can store the correspondence between feedback signals and predistortion parameters. After receiving the feedback signal after analog-to-digital conversion from the ADC output, the processor 403 can determine the predistortion parameter corresponding to the feedback signal according to the stored correspondence between the feedback signal and the predistortion parameter, and output the predistortion parameter to the DPD module corresponding to the feedback signal.

[0145] It should be noted that the correspondence between the feedback signal and the predistortion parameters can be found in Table 1 of the embodiments, and will not be repeated here.

[0146] Example 3

[0147] like Figure 7 The diagram shown is a schematic representation of a signal feedback circuit provided in an embodiment of this application.

[0148] The signal feedback circuit 400 includes a feedback circuit 401, an analog-to-digital conversion circuit 402, a selection circuit 404, and a processor 403.

[0149] The feedback circuit 401 includes a first coupler corresponding to at least one PA, a second coupler corresponding to at least one ET circuit, and a combiner corresponding to each PA. The selection circuit 404 includes a plurality of selection switches K. The analog-to-digital conversion circuit 402 includes an LPF and an ADC.

[0150] Specifically, the first coupler may include A1, the input of which is connected to the output of the corresponding PA. A1 can be used to attenuate the amplitude of the output signal of the connected PA and then output it. The second coupler may include A2, the input of which is connected to the output of the corresponding ET circuit. A2 can be used to attenuate the amplitude of the output signal of the connected ET circuit and then output it. The first input of the combiner is connected to the output of A1 connected to the corresponding PA, and the second input of the combiner is connected to the output of A2 connected to the ET circuit used to power the corresponding PA. The combiner can be used to combine the output signals of A1 and A2. After being combined into a single signal, the signal is output to K. The input of K is connected to the output of each combiner in the feedback circuit. K can be used to receive the signal output by each combiner and output the received signals sequentially according to the preset output order. The input of LPF is connected to the output of K, and the output of LPF is connected to ADC. LPF is used to filter the output signal of K and output it to ADC. ADC is connected to processor 403. ADC is used to perform analog-to-digital conversion on the output signal of LPF and output it to processor 403. Processor 403 can be used to generate predistortion parameters based on the received signal and output the predistortion parameters to the corresponding DPD core.

[0151] It should be noted that the frequency of the PA's output signal is much higher than that of the baseband signal. Therefore, the frequency difference of the combined feedback signal output by the combiner is large. Since the ADC can only process signals within a fixed frequency range at the same time, in order to ensure the working efficiency of the ADC and the quality of the feedback signal, the operating frequency of the ADC can be changed to reduce the frequency of the high-frequency signal in the combiner's output signal, so that the output signal of the combiner is within a certain frequency range.

[0152] For example, Figure 8 As shown, the combined signals output by the combiner include the reduced-amplitude output signal u1 of the ET circuit and the reduced-amplitude output signal u2 of the PA circuit. Here, u2 is the baseband frequency, and u1 is a high-frequency signal.

[0153] After receiving the combined signal and the control signal output by the receiving processor or baseband subsystem, the ADC down-converts the high-frequency signal u2 to obtain a signal with a similar baseband frequency, such as... Figure 9In the case of u2, u1 and u2 have similar frequencies and the frequencies of the combined signals are within a certain range. The ADC can process the signals in the combined signal simultaneously and output the processed signal to the processor.

[0154] In a specific implementation, K may include multiple input ports and a first output port. Each input port is connected to each feedback module 401 in a one-to-one correspondence, and the output port is connected to the analog-to-digital conversion module 403.

[0155] In actual use, the combiner in each feedback module 401 outputs one feedback signal. Therefore, when configuring the selection module 402, a 4-to-1 K-type, 8-to-1 K-type, 16-to-1 K-type, or other types of multiplexers can be selected according to the number of RF signal transmission circuits in the communication system. It should be noted that the structure of the selection module 402 in this embodiment is only illustrative; in actual use, other chips or devices can be selected.

[0156] It should be noted that each combiner in the feedback circuit 401 can combine two signals into one signal, and the ADC and LPF can process the two signals simultaneously, which shortens the time for the ADC and LPF to process the output signal of the feedback circuit 401 and improves the working efficiency of the signal feedback circuit 400.

[0157] In practice, since the signal output by the ADC is a combined signal of two signals, after the processor receives the signal, it splits the received signal and generates predistortion parameters based on the split signal, and outputs the predistortion parameters to the corresponding DPD core.

[0158] Example 4

[0159] like Figure 10 The diagram shown is a schematic representation of a signal feedback circuit provided in an embodiment of this application.

[0160] The signal feedback circuit 400 includes a feedback circuit 401, an analog-to-digital conversion circuit 402, a selection circuit 404, and a processor 403.

[0161] The feedback circuit 401 includes a first coupler corresponding to at least one PA, a second coupler corresponding to at least one ET circuit, and a combiner corresponding to each PA. The selection circuit 404 includes a plurality of selection switches K. The analog-to-digital conversion circuit 402 includes an LPF and an ADC.

[0162] In a specific implementation, the first coupler may include A1 and a mixer. The input of A1 is connected to the output of the corresponding PA, and the output of A1 is connected to the first input of the mixer. A1 can be used to attenuate the amplitude of the output signal of the connected PA and output it to the mixer. The second input of the mixer is connected to the input of the PA. The mixer can be used to perform frequency mixing processing on the signal output from A1 and output the mixed signal. The second coupler may include A2. The input of A2 is connected to the output of the corresponding ET circuit. A2 can be used to attenuate the amplitude of the output signal of the connected ET circuit and output it. The first input of the combiner is connected to the output of the mixer in the first coupler connected to the corresponding PA, and the second input of the combiner is connected to the input of the PA. The output of A2 in the second coupler connected to the ET circuit is connected to the combiner, which can combine the signal output from the connected mixer and the output signal from A2 into a single signal and output it to K. The input of K is connected to the output of each combiner, and K can receive the signal output from the combiner and output the received signal sequentially according to a preset output order. The input of LPF is connected to the input of K, and the output of LPF is connected to ADC, which is used to filter the signal output from K and output it to ADC. ADC is connected to processor 403, which is used to perform analog-to-digital conversion on the output signal of LPF and output it to processor 403. Processor 403 can generate predistortion parameters based on the received signal and output the predistortion parameters to the corresponding DPD core.

[0163] It should be noted that each combiner in the feedback circuit 401 can combine two signals into one signal, and the ADC and LPF can process the two signals simultaneously, which shortens the time for the ADC and LPF to process the output signal of the feedback circuit 401 and improves the working efficiency of the signal feedback circuit 400.

[0164] It should be noted that the frequency of the PA's output signal is much higher than that of the baseband signal. Since A1 is directly connected to the mixer, the mixer down-converts the PA output signal with the attenuation amplitude of A1's output. The frequency of the output signal is close to that of the baseband signal. When the combiner combines the output signals of A2 and the mixer, the frequency of the combined signal is within a certain range. After receiving the signal output by the combiner, the ADC can directly process the signal. Therefore, the ADC does not need to switch between the first and second frequencies, reducing the problems of low conversion efficiency and low conversion accuracy caused by the delay in ADC frequency switching.

[0165] It should be noted that the analog-to-digital conversion circuit in the signal feedback circuit provided in the previous embodiments of this application only includes one ADC and one LPF. In actual use, depending on the number and structure of the devices in the analog-to-digital conversion circuit provided in the foregoing embodiments, as well as the different feedback circuit structures, the signal feedback circuit provided in the embodiments of this application also has several other structures. The principles of other circuit structures are the same, and this application will not describe them in detail.

[0166] Based on the same inventive concept, embodiments of this application also provide a radio frequency circuit. For example, such as... Figure 11 As shown, the radio frequency circuit 1100 provided in this application embodiment may include at least one radio frequency transmission channel 1101 and a signal feedback circuit 1102.

[0167] In this configuration, at least one radio frequency transmission channel is connected to at least one power amplifier (PA), and at least one PA is connected to at least one envelope tracking (ET) circuit for powering the at least one PA. A first input terminal of the signal feedback circuit 1102 is connected to the output terminal of the at least one PA, and a second input terminal of the signal feedback circuit 1102 is connected to the output terminal of the at least one ET circuit. The signal feedback circuit 1102 is used to feedback the output signal of the at least one PA and the signal output by the at least one ET circuit, and outputs them through its output terminal. It should be noted that... Figure 11 Although only one radio frequency transmission channel is shown, the radio frequency circuit 1100 in the embodiments of this application is not limited thereto.

[0168] Each radio frequency (RF) transmit channel has its input terminal connected to a first digital predistortion (DPD) core, and the ET circuit used to power the PA connected to each RF transmit channel includes a second DPD core.

[0169] It is understandable that the circuit structure design of the signal feedback circuit 1102 in the above-mentioned radio frequency circuit can be referenced. Figures 4 to 10 The relevant design details will not be repeated here.

[0170] Based on the same technical concept, embodiments of this application also provide a communication system, exemplarily, such as... Figure 12As shown, the communication system 1200 provided in this application embodiment may include a baseband subsystem 1201, a radio frequency circuit 1202 connected to the baseband subsystem 1201, at least one PA 1203 connected to the radio frequency circuit, at least one ET circuit 1204 connected to the at least one PA, an antenna 1205 corresponding to the at least one PA 1203, and a signal feedback circuit 400 provided above in this application embodiment connected to the at least one PA 1203 and the at least one ET circuit 1204. Each ET circuit is used to power the connected PA, and the ET circuit includes an ET device, a power supply, a second DPD core, and a DAC.

[0171] Optionally, the communication system 1200 further includes at least one first DPD core (not shown), through which the baseband subsystem is connected to the radio frequency circuit 1202.

[0172] The baseband subsystem 1201 can be used to provide baseband signals to the radio frequency circuit 1202; the radio frequency circuit 1202 can be used to convert the baseband signals transmitted by the baseband subsystem 1201 into radio frequency signals and output the radio frequency signals to the corresponding antennas; the signal feedback circuit 400 can be used to configure the signal feedback path for the communication system 1200; each antenna is used to transmit and receive radio frequency signals.

[0173] In an alternative embodiment, the signal feedback circuit 400 may be fixedly connected to the radio frequency circuit 1202.

[0174] In one example, the communication system 1200 also includes an antenna switch 1206 connected between an antenna 1205 and at least one PA 1203.

[0175] In a specific implementation, the antenna switch 1206 can receive a control command sent by the baseband subsystem 1201 to control the state of the antenna switch 1206. After receiving the control command, the antenna switch 1206 adjusts the state of the switch to control the connection between the antenna 1206 and at least one PA 1203.

[0176] It should be noted that the term "multiple" in this application refers to two or more.

[0177] The connection involved in this application describes the connection relationship between two objects, which can represent two types of connection relationships. For example, the connection between A and B can represent two cases: A is directly connected to B, and A is connected to B through C.

[0178] In addition, it should be understood that in the description of this application, the words "first" and "second" are used only for the purpose of distinguishing descriptions and should not be construed as indicating or implying relative importance or order.

[0179] Furthermore, the system architecture and business scenarios provided in the embodiments of this application are mainly for explaining some possible implementations of the technical solutions of this application, and should not be construed as a unique limitation on the technical solutions of this application. Those skilled in the art will understand that as the system evolves and newer business scenarios emerge, the technical solutions provided in this application will still be applicable to the same or similar technical problems.

[0180] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the scope of protection of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A radio frequency circuit, characterized in that, The radio frequency circuit includes at least one radio frequency transmission channel and a signal feedback circuit; The at least one radio frequency transmission channel is connected to at least one power amplifier (PA), and the at least one PA is connected to at least one envelope tracking (ET) circuit for powering the at least one PA. The first input terminal of the signal feedback circuit is used to connect to the output terminal of the at least one PA, the second input terminal of the signal feedback circuit is used to connect to the output terminal of the at least one ET circuit, and the signal feedback circuit is used to feed back the output signal of the at least one PA and the signal output by the at least one ET circuit and output them through the output terminal of the signal feedback circuit. The input of each radio frequency transmit channel is connected to the first digital predistortion (DPD) core, and the ET circuit used to power the PA connected to each radio frequency transmit channel includes a second DPD core. The signal feedback circuit is connected to the baseband subsystem, which is used to generate predistortion parameters for the first DPD core and the second DPD core based on the signal output by the signal feedback circuit; or The signal feedback circuit further includes a processor, which is used to generate predistortion parameters for the first DPD core and the second DPD core based on the output signal of the at least one PA and the signal output by the at least one ET circuit.

2. The radio frequency circuit as described in claim 1, characterized in that, The signal feedback circuit includes: a feedback circuit and an analog-to-digital conversion circuit; The first input terminal of the feedback circuit is used to connect to the output terminal of the at least one PA, the second input terminal of the feedback circuit is used to connect to the output terminal of the at least one ET circuit, and the output terminal of the feedback circuit is connected to the input terminal of the analog-to-digital converter circuit. The analog-to-digital converter circuit is used to perform analog-to-digital conversion processing on the signal output by the feedback circuit and output it through the output terminal of the analog-to-digital converter circuit.

3. The radio frequency circuit as described in claim 2, characterized in that, The signal feedback circuit includes: a first coupler corresponding to the at least one PA and a second coupler corresponding to the at least one ET circuit; Each of the first couplers is connected to the output terminal of the corresponding PA, and each of the first couplers is used to feed back the output signal of the connected PA. Each of the second couplers is connected to the output terminal of the corresponding power supply circuit, and each of the second couplers is used to provide feedback on the output signal of the connected ET circuit.

4. The radio frequency circuit as described in claim 2 or 3, characterized in that, The radio frequency circuit includes multiple radio frequency transmission channels, and the at least one PA is connected to each of the multiple radio frequency transmission channels in a one-to-one correspondence. The signal feedback circuit also includes a selection circuit. The feedback circuit is connected to the analog-to-digital conversion circuit through the selection circuit. The selection circuit is used to output the signals output by the feedback circuit in sequence according to a preset output order.

5. The radio frequency circuit as described in claim 2 or 3, characterized in that, The analog-to-digital conversion circuit includes: a filter corresponding to each PA and an analog-to-digital converter corresponding to each filter; The input of each filter is connected to the feedback circuit. Each filter is used to receive the output signal of the corresponding PA and the output signal of the ET circuit connected to the corresponding PA, and outputs the received signal to the connected analog-to-digital converter after filtering. Each of the analog-to-digital converters is used to receive the signal output from the connected filter and perform analog-to-digital conversion on the received signal.

6. The radio frequency circuit as described in claim 3, characterized in that, The feedback circuit also includes: a combiner corresponding to each PA; Each combiner has its first input terminal connected to the output terminal of the first coupler connected to the corresponding PA, and its second input terminal connected to the output terminal of the second coupler connected to the ET circuit for powering the corresponding PA. The output terminal of each combiner is connected to the analog-to-digital converter circuit. Each combiner is used to combine the signals output by the connected first coupler and second coupler into one signal and output it to the analog-to-digital converter circuit.

7. The radio frequency circuit as described in claim 2 or 3, characterized in that, The processor is connected to the analog-to-digital converter circuit. The processor is used to receive the signal output by the analog-to-digital converter circuit and output a signal for adjusting the received signal of the radio frequency circuit and the output signal of the at least one ET circuit.

8. A signal feedback circuit applied in a communication system, the communication system comprising a radio frequency circuit, at least one power amplifier (PA) connected to the radio frequency circuit, and at least one envelope tracking (ET) circuit connected to the at least one PA for supplying power to the connected PA, characterized in that, The first input terminal of the signal feedback circuit is used to connect to the output terminal of the at least one PA, the second input terminal of the signal feedback circuit is used to connect to the output terminal of the at least one ET circuit, and the signal feedback circuit is used to feed back the output signal of the at least one PA and the signal output by the at least one ET circuit and output them through the output terminal of the signal feedback circuit. The radio frequency circuit connected to the at least one PA is connected to at least one first digital predistortion (DPD) core, and each ET circuit connected to the signal feedback circuit includes a second DPD core. The signal feedback circuit is connected to the baseband subsystem, which is used to generate predistortion parameters for the first DPD core and the second DPD core based on the signal output by the signal feedback circuit; or The signal feedback circuit further includes a processor, which is used to generate predistortion parameters for the first DPD core and the second DPD core based on the output signal of the at least one PA and the signal output by the at least one ET circuit.

9. The signal feedback circuit as described in claim 8, characterized in that, The signal feedback circuit includes: a feedback circuit and an analog-to-digital conversion circuit; The first input terminal of the feedback circuit is used to connect to the output terminal of the at least one PA, the second input terminal of the feedback circuit is used to connect to the output terminal of the at least one ET circuit, and the output terminal of the feedback circuit is connected to the input terminal of the analog-to-digital converter circuit. The analog-to-digital converter circuit is used to perform analog-to-digital conversion processing on the signal output by the feedback circuit and output it through the output terminal of the analog-to-digital converter circuit.

10. The signal feedback circuit as described in claim 9, characterized in that, The signal feedback circuit includes: a first coupler corresponding to the at least one PA and a second coupler corresponding to the at least one ET circuit; Each of the first couplers is connected to the output terminal of the corresponding PA, and each of the first couplers is used to feed back the output signal of the connected PA. Each of the second couplers is connected to the output of the corresponding ET circuit, and each of the second couplers is used to provide feedback on the output signal of the connected ET circuit.

11. The signal feedback circuit as described in claim 9 or 10, characterized in that, The radio frequency circuit includes multiple radio frequency transmission channels, and the at least one PA is connected to each of the multiple radio frequency transmission channels in a one-to-one correspondence. The signal feedback circuit also includes a selection circuit. The feedback circuit is connected to the analog-to-digital conversion circuit through the selection circuit. The selection circuit is used to output the signals output by the feedback circuit in sequence according to a preset output order.

12. The signal feedback circuit as described in claim 11, characterized in that, The analog-to-digital conversion circuit includes: a filter corresponding to each PA and an analog-to-digital converter corresponding to each filter; The input terminal of each filter is connected to the selection circuit. Each filter is used to receive the output signal of the corresponding PA and the output signal of the ET circuit connected to the corresponding PA, and outputs the received signal to the connected analog-to-digital converter after filtering. Each of the analog-to-digital converters is used to receive the signal output from the connected filter and perform analog-to-digital conversion on the received signal.

13. The signal feedback circuit as described in claim 10, characterized in that, The feedback circuit also includes: a combiner corresponding to each PA; Each combiner has a first input terminal connected to a first coupler connected to the corresponding PA, a second input terminal connected to a second coupler connected to an ET module for powering the corresponding PA, and an output terminal connected to the analog-to-digital converter circuit. Each combiner is used to combine the signals output from the connected first and second couplers into a single signal and output it to the analog-to-digital converter circuit.

14. The signal feedback circuit as described in claim 9 or 10, characterized in that, The processor is connected to the analog-to-digital converter circuit. The processor is used to receive the signal output by the analog-to-digital converter circuit and output a signal for adjusting the received signal of the radio frequency circuit and the output signal of the at least one ET circuit.

15. A communication system, characterized in that, include: Baseband subsystem; The radio frequency circuit connected to the baseband subsystem; At least one power amplifier PA connected to the radio frequency circuit; At least one envelope tracking ET circuit is connected to the at least one PA; each ET circuit is used to power the connected PA. Antennas that are connected one-to-one with the at least one PA; as well as A signal feedback circuit as described in any one of claims 8-14, connected to the at least one PA and the at least one ET circuit.

16. The communication system as described in claim 15, characterized in that, The signal feedback circuit is fixedly connected to the radio frequency circuit.

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