Vehicle-mounted radio receiving system

Abstract

The invention discloses a vehicle-mounted radio receiving system, and belongs to the technical field of radio receiving systems. A radio chip in the radio receiver is directly connected with the antenna, namely the radio chip is arranged close to the antenna, so that radio signals can be demodulated nearby, the transmission distance of the radio signals is reduced, and meanwhile, the radio receiver can be far away from an interference source (a switching power supply) in the domain controller. A digital audio signal demodulated by the radio chip is packed by the first Serdes chip and then transmitted to the domain controller, the digital audio signal is unpacked and restored to the digital audio signal by the second Serdes chip in the domain controller, and then the digital audio signal is processed by the digital signal processing unit and the sound driving unit, so that the attenuation distortion of the radio signal in the transmission process can be reduced, and the transmission efficiency of the radio signal is improved. And the anti-interference capability of wireless signals is improved.

Description

Technical Field

[0001] The present application belongs to the technical field of radio receiving systems, and in particular to a vehicle-mounted radio receiving system. Background Art

[0002] In related technologies, a radio reception system primarily consists of an antenna, antenna amplifier, coaxial cable, and receiver. The antenna receives radio electromagnetic waves from the air and converts them into voltage signals. The antenna amplifier amplifies the signal and transmits it to the receiver via a coaxial cable. The receiver, using related chips and circuits, filters and demodulates the signal to generate a received signal. This signal is then passed to the digital signal processing unit and power amplifier, which then drives the car's speakers for playback.

[0003] There are two disadvantages to using the above solution for radio signal reception: first, radio signals are attenuated during transmission and require an antenna amplifier to compensate for amplification. During this process, signal distortion may occur to a certain extent. Second, when the radio signal is processed by the receiver, it is affected by the switching power supply inside the receiver, especially the AM (amplitude modulation) frequency band, which is more significantly affected by the switching power supply inside the receiver. Summary of the Invention

[0004] An embodiment of the present application provides a vehicle-mounted radio receiving system. By placing a radio chip close to the antenna, the digital audio signal demodulated by the radio chip is packaged by a first SerDes chip and transmitted to a domain controller. The second SerDes chip in the domain controller unpacks the signal and restores it to a digital audio signal. The digital audio signal is then processed by a digital signal processing unit and a sound driving unit. This can reduce the attenuation and distortion of the radio signal during transmission and improve the anti-interference capability of the wireless signal.

[0005] Other features and advantages of the present application will become apparent from the following detailed description, or may be learned in part by practice of the present application.

[0006] According to a first aspect of an embodiment of the present application, there is provided a vehicle-mounted radio receiving system, comprising:

[0007] Antennas, which are used to capture electromagnetic waves in space and convert them into electrical signals;

[0008] A radio receiver includes a radio chip and a first SerDes chip, wherein the radio chip is connected to the antenna, and the first SerDes chip is connected to the radio chip; the radio chip is configured to filter and then demodulate the electrical signal transmitted from the antenna to output a digital audio signal to the first SerDes chip; the first SerDes chip is configured to package the digital audio signal to output a serial differential signal;

[0009] A domain controller, the domain controller is a receiver, and the domain controller includes a second SerDes chip, a digital signal processing unit and a sound driving unit connected in sequence, the second SerDes chip is connected to the first SerDes chip; the second SerDes chip is used to receive the serial differential signal and unpack the serial differential signal to restore the digital audio signal and output it to the digital signal processing unit; the digital signal processing unit is used to perform algorithm optimization and multi-channel management on the digital audio signal to output a multi-channel digital audio signal to the sound driving unit; the sound driving unit is used to convert the multi-channel digital audio signal into an analog audio signal and drive the speaker to produce sound.

[0010] In some embodiments of the present application, based on the aforementioned solution, the system further includes a coaxial cable, the domain controller is connected to the radio receiver via the coaxial cable, and the coaxial cable is used to transmit the serial differential signal output after processing by the first SerDes chip to the second SerDes chip.

[0011] In some embodiments of the present application, based on the aforementioned solution, the radio receiver is integrated into a first printed circuit board, and the first printed circuit board includes an input end impedance and an output end impedance, and the input end impedance matches the output end impedance of the antenna; the output end impedance matches the input impedance of the coaxial cable.

[0012] In some embodiments of the present application, based on the aforementioned solution, the first printed circuit board includes a digital ground and an analog ground, and the digital ground and the analog ground are separated.

[0013] In some embodiments of the present application, based on the aforementioned solution, the domain controller is integrated into a second printed circuit board, and the second printed circuit board includes an input impedance, and the input impedance matches the output impedance of the coaxial cable.

[0014] In some embodiments of the present application, based on the aforementioned solution, the domain controller further includes a power supply circuit, which is connected to the radio receiver through the coaxial cable to supply power to the radio receiver.

[0015] In some embodiments of the present application, based on the aforementioned solution, the domain controller further includes a microcontroller, and the microcontroller is connected to the second SerDes chip;

[0016] The microcontroller is used to send an initialization instruction to the chip link so that the second Serdes chip, the first Serdes chip and the radio chip on the chip link are initialized. The chip link includes the second Serdes chip, the first Serdes chip and the radio chip connected in sequence.

[0017] In some embodiments of the present application, based on the aforementioned solution, the microcontroller is further configured to send a mode switching instruction to the radio chip through the chip link, so that the radio chip switches between AM mode and FM mode based on the mode switching instruction.

[0018] In some embodiments of the present application, based on the aforementioned solution, the radio chip includes:

[0019] A filtering module, configured to filter the electrical signal transmitted from the antenna to obtain an AM signal or an FM signal of a target frequency band;

[0020] A demodulation module, configured to demodulate the AM signal or FM signal to obtain an analog audio signal;

[0021] The signal conversion module is used to perform ADC sampling and interface formatting processing on the analog audio signal to obtain a digital audio signal.

[0022] In some embodiments of the present application, based on the above solution, the filtering module includes:

[0023] AM mode, for filtering the electrical signal transmitted from the antenna through a medium and low frequency filter to filter out the AM signal of the target frequency band;

[0024] FM mode, for filtering the electrical signal transmitted from the antenna through a high-frequency filter to filter out FM signals of a target frequency band;

[0025] The demodulation module includes:

[0026] an amplitude demodulator, configured to demodulate the AM signal into an analog audio signal based on an envelope detection method;

[0027] The frequency demodulator is used to demodulate the FM signal into an analog audio signal based on a frequency discriminator.

[0028] Based on the technical solution proposed in this application, by directly connecting the radio chip in the radio receiver to the antenna, that is, by placing the radio chip close to the antenna, the radio signal can be demodulated nearby, reducing the transmission distance of the radio signal while also being away from interference sources within the domain controller (the switching power supply). The digital audio signal demodulated by the radio chip is packaged by a first SerDes chip and transmitted to the domain controller. A second SerDes chip within the domain controller then unpacks the signal and converts it into a digital audio signal, which is then processed by the digital signal processing unit and the sound driver unit. This reduces the attenuation and distortion of the radio signal during transmission and improves the anti-interference capability of the wireless signal.

[0029] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings are incorporated into and constitute a part of the specification, illustrating embodiments consistent with the present application and, together with the specification, explaining the principles of the present application. Obviously, the drawings described below are only some embodiments of the present application, and those skilled in the art can derive other drawings based on these drawings without inventive effort. In the drawings:

[0031] Figure 1 Schematic diagram of a car radio receiving system provided in one embodiment of the present application.

[0032] Figure 2 It is a structural diagram of a radio chip provided in one embodiment of the present application.

[0033] Reference numerals:

[0034] 100, antenna, 200, radio receiver, 300, domain controller;

[0035] 210, radio chip, 220, first SerDes chip, 211, filtering module, 212, demodulation module, 213, signal conversion module;

[0036] 310. Second SerDes chip, 320. Digital signal processing unit, 330. Sound driving unit, 340. Power supply circuit, 350. Microcontroller, 360. Display operation interface. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0038] In addition, described feature, structure or characteristic can be combined in one or more embodiments in any suitable manner.In the following description, many specific details are provided so as to provide a full understanding of the embodiments of the present application. However, it will be appreciated by those skilled in the art that the technical scheme of the present application can be put into practice without one or more of the specific details, or other methods, components, devices, steps etc. can be adopted. In other cases, known methods, devices, implementations or operations are not shown or described in detail to avoid blurring the various aspects of the application.

[0039] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically separate entities. That is, these functional entities may be implemented in software, in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0040] The flowcharts shown in the accompanying drawings are for illustrative purposes only and do not necessarily include all contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps may be decomposed, while others may be combined or partially combined. Therefore, the actual execution order may vary depending on the actual situation.

[0041] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0042] In order to enable those skilled in the art to better understand the present application, the application scenarios involved in the present application are first briefly described.

[0043] Explanation of terms:

[0044] Serdes, short for SERializer / DESerializer, is a mainstream time-division multiplexing (TDM) and point-to-point (P2P) serial communication technology. At the transmitting end, multiple low-speed parallel signals are converted into high-speed serial signals. These signals are then transmitted over the transmission medium (fiber optic cable or copper wire) and then converted back into low-speed parallel signals at the receiving end.

[0045] In order to solve the problems of attenuation, distortion, and interference of radio signals during transmission, the patent application with publication number CN212211014U discloses an FM radio anti-Class D power amplifier interference circuit, circuit board and FM radio. The FM radio anti-Class D power amplifier interference circuit receives the audio signal sent by the radio station through the radio module, and the audio signal is further transmitted to the isolation module. The audio signal is transmitted to the power amplifier module through the isolation module. The power amplifier module further amplifies the audio signal and outputs it through the speaker. The power amplifier module will generate interference signals through the ground wire during operation. The isolation module can prevent the current in the circuit from flowing directly from the radio module or the power amplifier module to the power amplifier. Module or radio module, blocking the mutual influence of interference signals between the two modules, that is, no direct current flow path is established between the radio module and the power amplifier module, but audio information can still be transmitted normally through the isolation module. In addition, an isolation transformer is provided between the first power supply that supplies power to the radio module and the isolation module on one side and the third power supply that supplies power to the power amplifier module and the second power supply that supplies power to the other side of the isolation module on one side. The isolation transformer further blocks the conducted interference signal caused by the direct flow of power-on current between the radio module and the power amplifier module. Through the design of the isolation transformer and the isolation module, the interference of the Class D power amplifier on the FM radio tuning can be effectively solved.

[0046] This solution can block the interference signals of Class D amplifiers through isolation modules and isolation transformers, but the introduction of these modules will increase system cost and volume, and can only isolate the interference introduced by the power supply.

[0047] Based on this, an embodiment of the present application provides a car radio receiving system. By placing the radio chip close to the antenna, the digital audio signal demodulated by the radio chip is packaged by a first SerDes chip and transmitted to the domain controller. The second SerDes chip in the domain controller unpacks the signal and restores it into a digital audio signal, which is then processed by a digital signal processing unit and a sound driving unit. This can reduce the attenuation and distortion of the radio signal during transmission and improve the anti-interference ability of the wireless signal.

[0048] Reference Figure 1 , Figure 1 Schematic diagram of a car radio receiving system provided by an embodiment of the present application. Figure 1 As shown, the car radio receiving system includes an antenna 100, a radio receiver 200 and a domain controller 300. The antenna 100 is connected to the radio receiver 200, and the radio receiver 200 is connected to the domain controller 300.

[0049] The antenna 100 is used to capture electromagnetic waves in space and convert them into electrical signals. Specifically, as a receiving end, the antenna 100 can capture electromagnetic waves of various frequencies propagating in space (including AM (Amplitude Modulation) / FM (Frequency Modulation) broadcast bands) through a metal conductor structure, and convert the electromagnetic wave energy into a high-frequency current signal. The high-frequency current signal is transmitted to a tuning circuit for subsequent processing. The antenna 100 can be a rear window glass antenna, and the overall effect of the antenna 100 needs to be within 10dB of the standard telescopic antenna.

[0050] The radio receiver 200 is primarily used to demodulate radio frequency signals into radio audio signals. The radio receiver 200 includes a radio chip 210 and a first SerDes chip 220. The radio chip 210 is connected to the antenna 100, and the first SerDes chip 220 is connected to the radio chip 210. The radio chip 210 filters and demodulates the electrical signals transmitted from the antenna 100, outputting digital audio signals (such as TDM signals or I2S signals) to the first SerDes chip 220. The first SerDes chip 220 packages the digital audio signals to output serial differential signals.

[0051] In the embodiment of the present application, by placing the radio chip close to the antenna, the radio signal can be demodulated nearby, reducing the transmission distance of the radio signal, and at the same time keeping away from the interference source (switching power supply) inside the domain controller 300.

[0052] Specifically, refer to Figure 2 , Figure 2 Schematic diagram of the structure of a radio chip provided by an embodiment of the present application. Figure 2As shown, the radio chip 210 includes a filtering module 211, a demodulation module 212, and a signal conversion module 213. The filtering module 211 is used to filter the electrical signal transmitted from the antenna 100 to obtain an AM signal or FM signal in the target frequency band. After the broadband electromagnetic signal (including multi-band interference) received by the antenna 100 is input into the radio chip 210, it can first be filtered out of the non-target frequency band through a radio frequency tuning circuit (such as an LC resonant circuit) to separate the pure AM or FM signal. For example, for AM reception, the 530kHz-1.6MHz frequency band is selectively filtered, while for FM reception, the 88MHz-108MHz frequency band is locked. The demodulation module 212 is used to demodulate the AM or FM signal to obtain an analog audio signal. For AM signals, envelope detection (a diode + capacitor circuit) can be used to directly extract the analog audio signal from the carrier amplitude envelope. For FM signals, a frequency detector (such as a slope frequency detector / phase-locked loop) can be used to convert frequency changes into amplitude changes, and then envelope detection is performed to output the audio signal. The signal conversion module 213 is used to perform ADC sampling and interface formatting on the analog audio signal to obtain a digital audio signal. The analog audio signal can be digitized by an analog-to-digital converter (ADC) at a sampling rate (such as 44.1kHz) to generate PCM (Pulse-Code Modulation) data. The PCM data is further encapsulated into two digital audio interface formats. The first is TDM (time division multiplexing), which is transmitted through multi-channel audio time-sharing. The second is I2S (Philips standard), which has a dedicated audio bus with a three-wire system of SCK (bit clock), WS (channel select), and SD (data line).

[0053] In some embodiments, the filtering module 211 includes:

[0054] AM mode, for filtering the electrical signal transmitted from the antenna through a medium and low frequency filter to filter out the AM signal of the target frequency band;

[0055] The FM mode is used to filter the electrical signal transmitted from the antenna through a high-frequency filter to filter out the FM signal of the target frequency band.

[0056] In this embodiment, the AM mode receives 525-1605kHz signals via antenna 100, which are initially filtered by the LC resonant circuit and then suppressed by an adjustable bandpass filter (BPF). In the FM mode, antenna 100 captures 87.5-108MHz signals, using a secondary frequency conversion technique (primary IF 10.7MHz → secondary IF 455kHz) in combination with a surface acoustic wave (SAW) filter to improve image rejection.

[0057] In some embodiments, the demodulation module 212 includes:

[0058] Amplitude demodulator, used to demodulate the AM signal into an analog audio signal based on envelope detection method;

[0059] The frequency demodulator is used to demodulate the FM signal into an analog audio signal based on a frequency discriminator.

[0060] In the embodiments of the present application, the amplitude demodulator specifically conducts the AM signal unidirectionally through a diode, intercepts the positive half-cycle waveform, and then extracts the envelope through an RC low-pass filter to restore the original audio signal. This allows the AM signal to be demodulated into an analog audio signal. The frequency demodulator utilizes LC circuit detuning to convert frequency deviation into amplitude variation, and then uses envelope detection to demodulate the FM signal into an analog audio signal.

[0061] The first SerDes chip 220 is used to package and process digital audio signals to output serial differential signals. Specifically, the first SerDes chip 220 first combines multiple parallel audio digital signals (such as a 24-bit audio stream in I2S / TDM format) into a single high-speed serial bit stream through a shift register, and then adds a frame synchronization header, control instructions (such as I2C frequency modulation instructions) and a check code to form a complete data frame structure. 8b / 10b or 64b / 66b encoding is then used to balance the "0 / 1" ratio in the data stream to ensure DC balance and clock recoverability. This converts the digital signal into an interference-resistant high-speed serial differential signal.

[0062] In the embodiment of the present application, the digital audio signal demodulated by the radio chip is packaged and converted into an interference-resistant high-speed serial differential signal by the first SerDes chip 220, which can effectively reduce signal distortion during signal transmission.

[0063] The domain controller 300 is a receiver, and includes a second Serdes chip 310 , a digital signal processing unit 320 , and a sound driving unit 330 , which are connected in sequence. The second Serdes chip 310 is connected to the first Serdes chip 220 .

[0064] Among them, the second SerDes chip 310 is used to receive the serial differential signal and unpack the serial differential signal to restore the digital audio signal and output it to the digital signal processing unit. Specifically, the second SerDes chip 310 extracts the embedded clock information from the high-speed serial differential signal (such as LVDS / CML), reconstructs the synchronous clock reference through the phase-locked loop (PLL), and eliminates the clock jitter of long-distance transmission. Then, the single-channel high-speed bit stream (such as 8 / 10b encoded data) is disassembled into multiple channels of parallel data through the shift register. Then, the control instructions and audio payload in the data frame are stripped, and an adaptive equalizer is used to compensate for the high-frequency attenuation during the transmission process, repairing the signal distortion caused by transmission loss, thereby restoring the digital audio signal.

[0065] The digital signal processing unit 320 is responsible for performing algorithm optimization and multi-channel management on the digital audio signal, outputting the multi-channel digital audio signal to the sound driver unit. Specifically, the digital signal processing unit 320 can suppress interference from ambient noise and reflections within the vehicle, and can also adjust the frequency response curve (such as enhancing low frequencies) to achieve virtual surround sound or independent zone audio output.

[0066] The sound driver unit 330 is used to convert the multi-channel digital audio signal into an analog audio signal and drive the speaker to produce sound. Specifically, the sound driver unit 330 can convert the PCM digital stream into a continuous voltage waveform through a digital-to-analog converter (DAC), thereby converting the multi-channel digital audio signal into an analog audio signal. At the same time, the sound driver unit 330 can also increase the signal strength to a level that can drive the speaker to produce sound.

[0067] In the embodiment of the present application, the digital audio signal demodulated by the radio chip 210 is packaged by the first SerDes chip 220 and transmitted to the domain controller, and then unpacked by the second SerDes chip 310 in the domain controller 300 to restore it into a digital audio signal, and then handed over to the digital signal processing unit 320 and the sound driving unit 330 for processing, which can reduce the attenuation and distortion of the radio signal during transmission and improve the anti-interference ability of the wireless signal.

[0068] In some embodiments, reference Figure 1 The car radio receiving system further includes a coaxial cable 400 , through which the domain controller 300 is connected to the radio receiver 200 . The coaxial cable 400 is used to transmit the serial differential signal processed and output by the first SerDes chip 220 to the second SerDes chip 310 .

[0069] In the embodiment of the present application, the coaxial cable 400 confines the signal between the central conductor and the shielding layer through electric field shielding, which can reduce signal attenuation and radiation interference.

[0070] In some embodiments, the radio receiver 200 is integrated on a first printed circuit board (PCB), and the radio chip 210 and the first SerDes chip 220 are respectively integrated on the first PCB. The first PCB includes an input impedance and an output impedance. The input impedance matches the output impedance of the antenna 100, and the output impedance matches the input impedance of the coaxial cable 400.

[0071] In the embodiment of the present application, the input impedance is matched to the output impedance of the antenna 100, meaning that the input impedance is equal to or highly similar to the output impedance of the antenna 100. The output impedance is matched to the input impedance of the coaxial cable 400, meaning that the output impedance is equal to or highly similar to the input impedance of the coaxial cable 400. Highly similar means that the impedance difference between the two is within a set range. Specifically, the input impedance must achieve conjugate matching (low-frequency circuit) or characteristic impedance matching (high-frequency circuit) with the output impedance of the antenna 100. When the output impedance of the antenna 100 is purely resistive (e.g., 50Ω), the input impedance of the first printed circuit board should also be adjusted to 50Ω to maximize power transmission. When the input impedance is equal to the output impedance of the antenna 100, the transmission efficiency of the electromagnetic wave energy from the antenna 100 to the radio receiver 200 can reach the highest level (theoretically up to 100%), and the signal power loss is minimized. The output impedance must be equal to the characteristic impedance of the coaxial cable 400 (typically 50Ω or 75Ω) to ensure that the signal energy is transmitted to the coaxial cable 400 without reflection.

[0072] In some embodiments, the radio receiver 200 is integrated into a first printed circuit board (PCB), which includes a digital ground and an analog ground, with the digital ground and the analog ground being separated. Specifically, the digital ground can provide a low-impedance return path for digital signals, carrying high-frequency switching noise (such as clock jumps and data flips). The analog ground can provide a "pure" reference level to prevent interference with weak analog signals (such as RF reception and audio amplification). The digital ground and the analog ground can be connected at a single location through a ferrite bead or a 0Ω resistor, that is, a single-point connection, and physically separated. The analog ground plane and the digital ground plane must not overlap in the PCB stack to avoid capacitive coupling noise.

[0073] In the embodiment of the present application, by designing the digital ground and analog ground separation in the first printed circuit board of the radio receiver 200, digital noise can be blocked from interfering with the analog signal, ensuring signal integrity and improving the anti-interference capability of the radio-related circuits.

[0074] In some embodiments, the domain controller 300 is integrated into a second printed circuit board (PCB), which includes an input impedance that matches the output impedance of the coaxial cable 400. Considering that when the characteristic impedance of the coaxial cable 400 does not match the input impedance of the second PCB, the signal may be reflected at the interface, resulting in waveform distortion (e.g., overshoot, undershoot) or energy loss. Therefore, the input impedance of the second PCB must match the characteristic impedance of the coaxial cable 400 (e.g., 50Ω or 75Ω) to ensure that the signal energy is transmitted to the domain controller 300 without reflection.

[0075] In some embodiments, reference Figure 1The domain controller 300 also includes a power supply circuit 340, which is connected to the radio receiver 200 via a coaxial cable 400 to provide power to the radio receiver 200. The coaxial cable 400 performs both power and RF signal transmission, replacing the traditional separate power and signal lines. This significantly reduces the number of cables, the weight of the vehicle wiring harness, and the space occupied by the wiring. Furthermore, the radio receiver 200 is powered via PoC, which simplifies the power supply design of the radio receiver 200.

[0076] In some embodiments, reference Figure 1 The domain controller 300 further includes a microcontroller 350 , which is connected to the second SerDes chip 310 .

[0077] The microcontroller 350 is used to send an initialization instruction to the chip link so that the second Serdes chip 310, the first Serdes chip 220 and the radio chip 210 on the chip link are initialized. The chip link includes the second Serdes chip 310, the first Serdes chip 220 and the radio chip 210 connected in sequence.

[0078] Specifically, the microcontroller 350 can be connected to the SPI / I 2 The C interface connects to the second SerDes chip 220. The second SerDes chip 310 receives parallel instructions (i.e., initialization instructions) sent by the microcontroller 350 and converts them into high-speed serial signals (such as the GMSL protocol). The signals are then transmitted to the first SerDes chip 220 via the coaxial cable 400. The first SerDes chip 220 deserializes and recovers the parallel data, forwarding it to the radio chip 210 to complete the initialization configuration. The microcontroller 350 configures the clock, interrupt vector table, and peripheral registers to generate an initialization instruction stream. The second SerDes chip 310 performs 8b / 10b encoding. The first SerDes chip 220 uses CDR (clock data recovery) to achieve bit / word alignment. The radio chip 210 writes register parameters such as the PLL (Phase Locked Loop) frequency and intermediate frequency bandwidth to complete the RF front-end initialization. This embodiment of the present application uses the microcontroller 350 to coordinate the initialization timing, avoiding conflicts caused by asynchronous operation of multiple devices. Furthermore, the radio receiver 200 does not require a built-in controller.

[0079] In some embodiments, the microcontroller 350 is further configured to send a mode switching instruction to the radio chip 210 via the chip link, so that the radio chip switches between the AM mode and the FM mode based on the mode switching instruction.

[0080] Specifically, the microcontroller 350 can 2The C bus generates 16-bit control parameters, which may include the target frequency band (AM: 520-1710kHz / FM: 87.5-108MHz) and the demodulation algorithm identifier. The switching command is converted into a differential signal (such as the GMSL protocol) by the second SerDes chip 310 and transmitted to the first SerDes chip 220 via the coaxial cable 400. After performing clock and data recovery, the first SerDes chip 220 sends the parallel data to the radio chip 210. After receiving the command, the radio chip 210 switches between AM and FM modes.

[0081] In the embodiment of the present application, the radio receiver 200 does not need a built-in controller and is centrally controlled and managed by the domain controller 300, which can reduce the BOM cost. The full-duplex transmission of the Serdes link can ensure an immediate response to the mode switching command.

[0082] In some embodiments, reference Figure 1 The domain controller 300 also includes a display interface 360, which is connected to the microcontroller 350. Users can switch audio sources, adjust frequencies, and control volume by pressing buttons or touching options on the display interface 360. The display interface 360 ​​also displays the current frequency (e.g., 87.5MHz), signal strength, and station name, and can display playback status indicators (e.g., stereo identification, favorites). The display interface 360 ​​also allows users to adjust audio effects (e.g., bass and treble balance, channel settings), and set regional frequency bands.

[0083] The embodiments described in the embodiments of this application are intended to more clearly illustrate the technical solutions of the embodiments of this application and do not constitute a limitation on the technical solutions provided by the embodiments of this application. Those skilled in the art will appreciate that with the evolution of technology and the emergence of new application scenarios, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

[0084] Those skilled in the art will understand that the technical solutions shown in the figures do not constitute a limitation on the embodiments of the present application, and may include more or fewer steps than shown in the figures, or a combination of certain steps, or different steps.

[0085] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, i.e., they may be located in one place or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of this embodiment.

[0086] Those skilled in the art will appreciate that all or some of the steps in the methods, systems, and functional modules / units in the devices disclosed above may be implemented as software, firmware, hardware, or appropriate combinations thereof.

[0087] The terms "first", "second", "third", "fourth", etc. (if any) in the specification of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0088] It should be understood that in this application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0089] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the above-mentioned units is only a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0090] The units described above as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0091] In addition, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0092] The foregoing is merely an embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of the claims of the present application.

Claims

1. A car radio receiving system, characterized in that: include: Antennas, which are used to capture electromagnetic waves in space and convert them into electrical signals; A radio receiver, comprising a radio chip and a first SerDes chip, wherein the radio chip is connected to the antenna, and the first SerDes chip is connected to the radio chip; the radio chip is configured to filter and then demodulate the electrical signal transmitted from the antenna to output a digital audio signal to the first SerDes chip; The first SerDes chip is used to package the digital audio signal to output a serial differential signal; A domain controller, the domain controller being a receiver, comprising a second SerDes chip, a digital signal processing unit, and a sound driving unit connected in sequence, wherein the second SerDes chip is connected to the first SerDes chip; the second SerDes chip is configured to receive the serial differential signal, unpack the serial differential signal, and restore the digital audio signal to output the digital audio signal to the digital signal processing unit; The digital signal processing unit is used to perform algorithm optimization and multi-channel management on the digital audio signal to output a multi-channel digital audio signal to the sound driving unit; the sound driving unit is used to convert the multi-channel digital audio signal into an analog audio signal and drive the speaker to produce sound.

2. The system according to claim 1, wherein: The system further includes a coaxial cable, through which the domain controller is connected to the radio receiver, and the coaxial cable is used to transmit the serial differential signal output after processing by the first SerDes chip to the second SerDes chip.

3. The system according to claim 2, characterized in that The radio receiver is integrated on a first printed circuit board. The first printed circuit board includes an input impedance and an output impedance. The input impedance matches the output impedance of the antenna; the output impedance matches the input impedance of the coaxial cable.

4. The system according to claim 3, characterized in that The first printed circuit board includes a digital ground and an analog ground, and the digital ground and the analog ground are separated.

5. The system according to claim 2, wherein: The domain controller is integrated on a second printed circuit board, and the second printed circuit board includes an input impedance, and the input impedance matches the output impedance of the coaxial cable.

6. The system according to claim 2, wherein: The domain controller further includes a power supply circuit connected to the radio receiver through the coaxial cable to supply power to the radio receiver.

7. The system according to claim 1, wherein: The domain controller further includes a microcontroller, and the microcontroller is connected to the second SerDes chip; The microcontroller is used to send an initialization instruction to the chip link so that the second Serdes chip, the first Serdes chip and the radio chip on the chip link are initialized. The chip link includes the second Serdes chip, the first Serdes chip and the radio chip connected in sequence.

8. The system according to claim 8, characterized in that The microcontroller is further configured to send a mode switching instruction to the radio chip through the chip link, so that the radio chip switches between the AM mode and the FM mode based on the mode switching instruction.

9. The system according to claim 1, wherein: The radio chip includes: A filtering module, configured to filter the electrical signal transmitted from the antenna to obtain an AM signal or an FM signal of a target frequency band; A demodulation module, configured to demodulate the AM signal or FM signal to obtain an analog audio signal; The signal conversion module is used to perform ADC sampling and interface formatting processing on the analog audio signal to obtain a digital audio signal.

10. The system according to claim 9, characterized in that The filtering module includes: AM mode, for filtering the electrical signal transmitted from the antenna through a medium and low frequency filter to filter out the AM signal of the target frequency band; FM mode, for filtering the electrical signal transmitted from the antenna through a high-frequency filter to filter out FM signals of a target frequency band; The demodulation module includes: an amplitude demodulator, configured to demodulate the AM signal into an analog audio signal based on an envelope detection method; The frequency demodulator is used to demodulate the FM signal into an analog audio signal based on a frequency discriminator.

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