Audio signal transmission system, audio signal transmission method and automobile
By using a differential signal transmission system, the sound quality problem of audio equipment under electromagnetic interference is solved, and stable transmission and high-quality output of audio signals are achieved, meeting the needs of modern audio systems.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-31
- Publication Date
- 2026-04-07
AI Technical Summary
In existing technologies, audio devices are affected by electromagnetic interference during transmission, resulting in a decline in audio quality. Audio systems that are difficult to solve with existing technologies cannot meet modern needs.
A differential signal transmission system is adopted, which converts the audio signal generated by the host into a differential signal, and uses a central computing unit and multiple zone controllers; the zone controllers; the zone controllers; the zone controllers; the zone transmission system, and transmit the audio signal through an audio bus.
It achieves efficient and stable audio transmission quality, distinguishes the integrity of signals during transmission, provides a stable and high-quality signal source for automotive audio systems, ensures the normal transmission and use of various types of signals, and further guarantees sound quality.
Smart Images
Figure CN121815162A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of signal transmission, in particular to an audio signal transmission system, an audio signal transmission method and a car. BACKGROUND
[0002] In traditional audio signal transmission, due to the complex electromagnetic environment, the audio equipment is easily affected by the surrounding electromagnetic interference, resulting in the decline of sound quality, the occurrence of noise, distortion and other problems. For example, DC-DC switching power supply and the like can produce high-frequency noise interference, which affects the quality of the host signal source, and the traditional audio transmission mode is difficult to ensure the purity of the sound quality.
[0003] In addition, the audio system usually needs to transmit various types of audio signals, and has certain requirements on the transmission distance and signal quality. The traditional transmission mode may need multiple cables to transmit different types of signals, which not only increases the cost and wiring difficulty, but also easily causes signal attenuation, loss and other problems in long-distance transmission, directly affecting the final sound quality presentation, and cannot meet the demand of modern car audio system for efficient and stable transmission. SUMMARY
[0004] The present application provides an audio signal transmission system, an audio signal transmission method and a car to solve the above technical problems.
[0005] Specifically, the present application provides an audio signal transmission system, comprising a central computing unit and a plurality of zone controllers; the central computing unit at least comprises a host and a bus master node; the zone controller at least comprises a bus slave node, and each bus slave node is connected in series to the bus master node through an audio bus; the bus master node is used to convert the audio signal generated by the host into a differential signal, and transmit the differential signal to each bus slave node in turn through the audio bus; and the bus slave node is used to receive the differential signal and drive a local audio device.
[0006] In the above technical solution, the audio signal generated by the host is converted into a differential signal for transmission, and the characteristics of the differential signal can well suppress electromagnetic interference, making the audio signal more pure, thereby significantly improving the sound quality and bringing better auditory experience to the user; and using one audio bus for signal transmission can ensure the integrity of the signal in the transmission process, providing a stable and high-quality signal source for the car audio system, ensuring the normal transmission and use of various types of signals, and further ensuring the sound quality.
[0007] Further, the central computing unit further comprises a digital signal processor connected with the bus master node, used for preprocessing the audio signal generated by the host.
[0008] In the technical solution, the digital signal processor (DSP) pre-processes the audio signal generated by the host computer, which can optimize the quality of the audio signal; for example, it can perform audio filtering to remove unnecessary noise and interference signals, adjust the frequency response, dynamic range and other parameters of the audio, so that the subsequent audio signal converted into a differential signal for transmission is of high quality, laying a foundation for the final good sound quality effect.
[0009] Further, the zone controller further comprises an audio processing circuit, which is connected with the bus slave node, and is used for performing digital-to-analog conversion and / or power amplification on the received differential signal and outputting the differential signal to a loudspeaker.
[0010] In the technical solution, the audio processing circuit performs digital-to-analog conversion on the received differential signal, converts the digital audio signal into an analog signal, because the loudspeaker and other audio devices usually need an analog signal to drive the sound; power amplification can enhance the power of the audio signal, so that the loudspeaker can output loud enough sound to meet the volume requirements in different scenarios and ensure that the audio can be played clearly and loudly.
[0011] Further, the audio processing circuit is further used for performing analog-to-digital conversion on the analog signal collected by the microphone and uploading the analog signal to the host computer through the bus slave node.
[0012] In the technical solution, in some scenarios requiring audio input, such as vehicle call, voice control, etc., the microphone collects an analog signal; the audio processing circuit performs analog-to-digital conversion on the analog signal to convert the analog signal into a digital signal, which is convenient for uploading to the host computer for processing through the bus slave node; the digital signal is more stable during transmission and has stronger anti-interference ability, which can accurately transmit the sound information collected by the microphone to the host computer to realize the function of bidirectional transmission of audio.
[0013] Further, the host computer is further used for dynamically identifying the newly connected bus slave node when a new zone controller is hot-plugged on the audio bus, and updating the audio channel mapping relationship.
[0014] In the technical solution, the user can add or replace audio devices at any time as needed without complex manual configuration; the system can automatically adapt to the access of new devices to ensure that the audio signal can be correctly distributed to each audio channel and ensure the normal operation of the entire audio system.
[0015] Further, the audio bus provides phantom power for the bus slave node.
[0016] The above technical solution further simplifies the system's wiring structure, reduces costs and wiring difficulty; at the same time, unified power supply through the audio bus ensures power stability and consistency, reduces audio equipment failures caused by power supply problems, and improves system reliability.
[0017] Based on the same concept, this application also provides an audio signal transmission method, comprising the following steps: generating an audio signal through the host of a central computing unit, and converting the audio signal into a differential signal through a bus master node; transmitting the differential signal to a bus slave node of a zone controller through an audio bus; and restoring audio data based on the differential signal through the bus slave node and outputting it to a local audio device.
[0018] In the above technical solutions, differential signals have strong anti-interference capabilities. In complex electromagnetic environments, such as inside a car, differential signals can effectively suppress common-mode interference, ensuring the integrity and accuracy of audio signals during transmission. Compared to single-ended signals, differential signals can better maintain signal quality and reduce signal distortion and attenuation during long-distance transmission, thereby improving the final sound quality. The audio bus enables efficient transmission of audio signals. It can simultaneously transmit multiple types of signals such as audio, video, and control data, and can ensure low signal loss during long-distance transmission. This allows the system to meet the needs of modern audio systems for multi-signal, long-distance transmission, providing support for the intelligence and integration of audio systems.
[0019] Furthermore, before converting the audio signal into a differential signal, the method further includes preprocessing the audio signal.
[0020] In the above technical solution, preprocessing is performed before converting the audio signal into a differential signal. As mentioned above, this can optimize the quality of the audio signal. Preprocessing can adjust the audio signal according to different application scenarios and needs, improve the clarity, sound quality and other indicators of the audio, and make the final output audio effect better.
[0021] Furthermore, when a new audio device node is connected to the audio bus, the process includes: registering the new audio device node in the host, and assigning a logical address to the new audio device node and updating the audio channel mapping relationship.
[0022] In the above technical solution, when a new audio device node is connected to the audio bus, the audio channel mapping relationship is registered and updated in the host, ensuring the system's compatibility and scalability. The new device can be quickly and accurately integrated into the existing audio system, and the system can automatically adjust the distribution and processing of audio signals to ensure that all audio devices can work normally, providing users with a seamless user experience.
[0023] Based on the same concept, this application also provides an automobile including the aforementioned audio signal transmission system.
[0024] Compared with the prior art, the beneficial effects of this application are as follows: This application utilizes the characteristics of differential signals to suppress electromagnetic interference, thereby significantly improving sound quality and providing users with a better listening experience; furthermore, using a single audio bus for signal transmission ensures the integrity of the signal during transmission, providing a stable and high-quality signal source for the automotive audio system, guaranteeing the normal transmission and use of various types of signals, and further ensuring sound quality. Attached Figure Description
[0025] Figure 1 This is a framework diagram of the audio signal transmission system described in this application.
[0026] Figure 2 This is a schematic diagram showing the connection between the central computing unit and the area controller according to an embodiment of this application.
[0027] Figure 3 This is a schematic diagram showing the connection between the central computing unit and the area controller according to another embodiment of this application.
[0028] Figure 4 This is a schematic diagram showing the connection between the central computing unit and the zone controllers according to an embodiment of this application.
[0029] Figure 5 This is a flowchart of the audio signal transmission method described in this application. Detailed Implementation
[0030] The following detailed description of an audio signal transmission system, audio signal transmission method, and automobile of this application, with reference to specific embodiments and accompanying drawings, provides further insight.
[0031] Please see Figure 1 This application provides an audio signal transmission system, including a central computing unit and multiple zone controllers; the central computing unit includes at least a host and a bus master node; the zone controllers include at least bus slave nodes, each bus slave node being connected in series to the bus master node via an audio bus; the bus master node is used to convert the audio signal generated by the host into a differential signal, so as to transmit it sequentially to each bus slave node via the audio bus; the bus slave nodes are used to receive the differential signal and drive local audio devices.
[0032] In some embodiments, the audio bus is preferably an A2B (Automotive Audio Bus) cable, which is a cable used in automotive audio systems. The audio bus connects the various zone controllers and the central computing unit, enabling fast and stable transmission of audio data, control signals, etc., reducing traditional complex wiring, and lowering the electromagnetic interference and weight of the system.
[0033] Specifically, in one feasible implementation, the audio signal generated by the host is encoded and modulated by the bus master node, converting it into a differential signal suitable for transmission over A2B cables. The differential signal is transmitted over A2B cables, utilizing their anti-interference characteristics to effectively resist high-frequency noise interference from DC-DC switching power supplies and other sources in the vehicle environment. Simultaneously, audio, video, control data, and power signals are transmitted in an orderly manner in a single cable. After reaching each bus slave node, the bus slave node demodulates and decodes the received signals, restoring them into usable audio signals for speaker playback. This achieves high-quality audio signal transmission and playback throughout the automotive audio system, optimizing sound quality performance.
[0034] Furthermore, the central computing unit also includes a digital signal processor, which is connected to the bus master node and is used to preprocess the audio signals generated by the host.
[0035] In some embodiments, the central computing unit is located in the center of the vehicle and is the core control unit of the entire transmission system. It communicates with each zone controller through the A2B cable to achieve centralized processing and control of audio signals, ensuring efficient transmission of audio signals between modules.
[0036] Specifically, the audio signal generated by the host is first transmitted to a digital signal processor (DSP). The DSP preprocesses the audio signal, for example, by using a low-pass filter to remove high-frequency noise and using a compressor to adjust the dynamic range of the audio, making the audio signal smoother and more stable.
[0037] The audio signal processed by the DSP will be transmitted to the TDM interface (e.g., Figure 2 (as shown) or I2S interface (such as) Figure 3(As shown in the diagram). The TDM interface coordinates audio data transmission through TDM_CN (TDM control signal) and TDM_SPNC (TDM synchronization signal). Audio signals enter the TDM interface via TDM_IN, undergo time-division multiplexing within the TDM interface, and are then output as integrated audio data via TDM_OUT. The TDM synchronization signal TDM_SPNC ensures that data from each audio channel is transmitted within the correct time slice, guaranteeing data synchronization and accuracy. It should be noted that TDM technology multiplexes signals from multiple audio channels within different time slices, enabling simultaneous transmission of multiple audio signals. The I2S interface, on the other hand, separates audio and clock signals for transmission. Dedicated clock lines synchronize data transmission, including a bit clock (BCLK) to synchronize the transmission of each bit and left / right channel clocks (LRCK) to distinguish between left and right channel data. This separation makes data transmission more stable and accurate, effectively avoiding timing issues during data transmission. Furthermore, the audio signal output from the TDM interface or I2S interface is transmitted to the bus master node. The bus master node first encodes the audio signal, for example, using Manchester encoding, converting each bit into two level changes. This encoding method has self-synchronization capability, which can accurately recover the original data at the receiving end, and also enhances the anti-interference capability of data transmission. The encoded audio signal is modulated onto the carrier signal of the audio bus. The audio bus uses differential signal transmission. By modulating the encoded data into a differential signal, electromagnetic interference can be effectively suppressed.
[0038] In addition, it should be noted that the bus master node, as the master controller of the audio bus, is responsible for scheduling the transmission of audio data. It allocates transmission time slices to each zone controller (slave node) according to the system configuration and requirements, ensuring that each slave node can receive and send audio signals in an orderly manner.
[0039] In the above technical solution, the digital signal processor (DSP) preprocesses the audio signal generated by the host, which can optimize the quality of the audio signal. For example, it can perform audio filtering to remove unnecessary noise and interference signals, and adjust parameters such as the frequency response and dynamic range of the audio, so that the audio signal that is subsequently converted into a differential signal for transmission is of higher quality, laying the foundation for a good final sound quality effect.
[0040] Furthermore, the area controller also includes an audio processing circuit connected to the bus slave node, which is used to perform digital-to-analog conversion and / or power amplification on the received differential signal before outputting it to the speaker.
[0041] In some embodiments, the speaker is used to play audio and provide sound output for the occupants of the vehicle. For example, when there is an incoming call, the host receives the voice digital signal transmitted over the network, processes it, and sends it to the bus slave node of the area controller in the form of a differential signal. The audio processing circuit performs digital-to-analog conversion and power amplification. If the other party speaks a sentence, the digital signal is converted and amplified, and then played clearly through the vehicle speaker so that the occupants of the vehicle can hear the other party's voice clearly.
[0042] The transmission of differential signals is coordinated through TDM_CN (TDM control signal) and TDM_SPNC (TDM synchronization signal); and the bus slave node outputs the integrated differential signal to the audio processing circuit through TDM_OUT.
[0043] In the above technical solution, the audio processing circuit performs digital-to-analog conversion on the received differential signal, converting the digital audio signal into an analog signal, because audio devices such as speakers usually require analog signals to drive sound production; the power amplifier can enhance the power of the audio signal, enabling the speaker to output a sufficiently loud sound to meet the volume requirements in different scenarios and ensure that the audio can be played clearly and loudly.
[0044] Furthermore, the audio processing circuit is also used to perform analog-to-digital conversion on the analog signals collected by the microphone and then upload them from the node to the host via the bus.
[0045] In some embodiments, the microphone collects in-vehicle sound signals and connects to the bus slave node of the zone controller via, for example, a PDM interface. For example, when a passenger in the vehicle issues a voice command to "turn on the air conditioning," the microphone collects this analog voice signal, the audio processing circuit performs analog-to-digital conversion on it, and the converted digital signal is uploaded to the host via the bus slave node. The host identifies and analyzes the digital signal and converts it into a corresponding control command to control the vehicle's air conditioning system to turn on.
[0046] The digital signal obtained after conversion by the audio processing circuit enters the bus slave node through, for example, TDM_IN.
[0047] In the above technical solution, in some scenarios that require audio input, such as in-vehicle calls and voice control, the microphone collects analog signals; the audio processing circuit performs analog-to-digital conversion on these signals, converting them into digital signals, which are then uploaded from the node to the host for processing via the bus; digital signals are more stable during transmission and have stronger anti-interference capabilities, enabling the accurate transmission of sound information collected by the microphone to the host, thus realizing bidirectional audio transmission.
[0048] In some embodiments, for example, four zone controllers are provided, such as Figure 4As shown, it includes a left front zone module, a right front zone module, a left rear zone module, and a right rear zone module. The left front zone module is responsible for managing the audio devices in the left front zone, receiving audio signals from the central computing unit and forwarding them to the speakers in the left front zone module. At the same time, it uploads the signals collected by the microphone and other devices to the central computing unit. The functions of the other modules are similar to those of the left front zone module, and they are responsible for the audio acquisition and playback of their respective zones.
[0049] Furthermore, the host is also used to dynamically identify newly connected bus slave nodes and update the audio channel mapping relationship when a new zone controller is hot-plugged onto the audio bus.
[0050] In some embodiments, the configuration of the transmission system is updated in the host, adding new audio device information, including its address on the bus, audio channel mapping and other parameters, so that the central computing unit can identify and control the newly added audio device. Then, based on the location of the newly added audio output channel and the connected speaker, the audio signal distribution logic is readjusted to ensure that the audio signal can be correctly transmitted to the newly added device, so as to achieve uniform audio distribution and optimized sound field effect.
[0051] In other embodiments, those skilled in the art can also optimize the audio processing algorithm according to actual application needs to adapt to the expansion of the system, such as adjusting parameters such as audio equalization and sound field adjustment, so that the entire audio system can still provide a high-quality audio experience after adding new audio devices.
[0052] In the above technical solution, users can add or replace audio devices at any time as needed without complicated manual configuration; the system can automatically adapt to the access of new devices, ensuring that audio signals can be correctly distributed to each audio channel, and ensuring the normal operation of the entire audio system.
[0053] Furthermore, the audio bus provides phantom power to the bus slave nodes.
[0054] The above technical solution further simplifies the system's wiring structure, reduces costs and wiring difficulty; at the same time, unified power supply through the audio bus ensures power stability and consistency, reduces audio equipment failures caused by power supply problems, and improves system reliability.
[0055] Furthermore, such as Figure 2As shown in Figure 3, the area controller is usually also equipped with a control unit with functions similar to the host in the central computing unit. The host configures the attributes of the bus master node through I2C, controls and resets the bus master node through GPIO, and a software upgrade interface SPI is reserved between the host and the bus master node. The control unit configures the bus slave node and audio processing circuit through I2C. Those skilled in the art can determine whether to configure the GPIO interface according to the actual application requirements. A software upgrade interface SPI is also reserved between the control unit and the bus slave node.
[0056] In summary, the audio signal transmission method described in this application converts the audio signal generated by the host into a differential signal for transmission. Utilizing the characteristics of differential signals, electromagnetic interference can be effectively suppressed, resulting in a purer audio signal and significantly improved sound quality, providing users with a better listening experience. Furthermore, using a single audio bus for signal transmission ensures signal integrity during transmission, providing a stable and high-quality signal source for the automotive audio system, guaranteeing the normal transmission and use of various signal types, and further ensuring sound quality. Simultaneously, using a single cable to transmit multiple signals facilitates internal wiring and system integration within the vehicle, reducing system costs and maintenance difficulty, and improving system reliability and maintainability.
[0057] Based on the same concept, please refer to Figure 5 This application also provides an audio signal transmission method, comprising the following steps: generating an audio signal through the host of a central computing unit, and converting the audio signal into a differential signal through a bus master node; transmitting the differential signal to a bus slave node of a zone controller through an audio bus; and restoring audio data based on the differential signal through the bus slave node and outputting it to a local audio device.
[0058] Furthermore, before converting the audio signal into a differential signal, the method further includes preprocessing the audio signal.
[0059] In the above technical solution, preprocessing is performed before converting the audio signal into a differential signal. As mentioned above, this can optimize the quality of the audio signal. Preprocessing can adjust the audio signal according to different application scenarios and needs, improve the clarity, sound quality and other indicators of the audio, and make the final output audio effect better.
[0060] In some embodiments, for example, a user clicks to play a popular song on the in-vehicle multimedia screen, the host reads the music file from the storage device and generates an audio signal; then, the bus master node converts the audio signal into a differential signal; before the conversion, the digital signal processor preprocesses the audio signal, such as using a low-pass filter to remove high-frequency noise, adjusting the frequency response and dynamic range of the audio, making the audio signal purer and smoother.
[0061] Furthermore, the converted differential signal is transmitted to the bus slave node of each zone controller via an audio bus (such as an A2B cable). For example, in a car equipped with four zone controllers (left front zone module, right front zone module, left rear zone module, and right rear zone module), the differential signal is transmitted sequentially to the bus slave node of each module. After receiving the differential signal, the bus slave node restores it to usable audio data. The audio processing circuit performs digital-to-analog conversion and power amplification on the restored audio data, and then outputs it to the local speaker so that the occupants can hear clear and loud music.
[0062] In other embodiments, for example, when a passenger in the vehicle issues a voice command to "turn on the air conditioning," the microphone picks up this analog voice signal, the audio processing circuit performs analog-to-digital conversion, converting the analog voice signal into a digital signal, and the bus uploads the digital signal from the node to the host. The host identifies and analyzes the uploaded digital signal, converts it into a corresponding control command, and controls the vehicle's air conditioning system to turn on. At the same time, if the host needs to provide feedback on the operation result to the passenger in the vehicle (such as a voice prompt "the air conditioning is on"), the host generates a corresponding audio signal, which is preprocessed, converted into a differential signal, and then transmitted to the zone controller through the audio bus, and finally played to the passenger through the speaker.
[0063] Furthermore, when a new audio device node is connected to the audio bus, the process includes: registering the new audio device node in the host, and assigning a logical address to the new audio device node and updating the audio channel mapping relationship.
[0064] In some embodiments, suppose a user adds a rear surround sound speaker to the audio bus to improve the in-vehicle audio effect; after the host detects the new device connection, it dynamically identifies the newly connected bus slave node, registers the newly added audio device node in the host, and assigns it a logical address; for example, the host assigns a unique address to the new speaker so that it can accurately identify and control the device.
[0065] The host system updates the audio channel mapping, adds new audio device information, including its address on the bus, audio channel mapping, and other parameters. Based on the location of the newly added audio output channels and connected speakers, it readjusts the audio signal distribution logic. For example, the host adjusts the audio signal distribution so that some audio signals can be correctly transmitted to the newly added rear surround sound speakers, achieving uniform audio distribution and optimized sound field effects. Simultaneously, it may optimize the audio processing algorithms, such as adjusting audio equalization and sound field adjustment parameters, so that the entire audio system can still provide a high-quality audio experience after adding new devices.
[0066] In the above technical solution, when a new audio device node is connected to the audio bus, the audio channel mapping relationship is registered and updated in the host, ensuring the system's compatibility and scalability. The new device can be quickly and accurately integrated into the existing audio system, and the system can automatically adjust the distribution and processing of audio signals to ensure that all audio devices can work normally, providing users with a seamless user experience.
[0067] In summary, differential signals possess strong anti-interference capabilities. In complex electromagnetic environments, such as inside a car, differential signals can effectively suppress common-mode interference, ensuring the integrity and accuracy of audio signals during transmission. Compared to single-ended signals, differential signals can better maintain signal quality and reduce signal distortion and attenuation during long-distance transmission, thereby improving the final sound quality. The audio bus enables efficient transmission of audio signals, simultaneously transmitting multiple types of signals such as audio, video, and control data, while ensuring low signal loss during long-distance transmission. This allows the system to meet the needs of modern audio systems for multi-signal, long-distance transmission, providing support for the intelligence and integration of audio systems.
[0068] Based on the same concept, this application also provides an automobile including the aforementioned audio signal transmission system.
[0069] In some embodiments, for example, the host of the audio signal transmission system is installed at the front of the car, connected to the bus master node, and an audio bus (such as an A2B cable) is laid from the seat to connect the bus slave nodes of audio devices such as the cabin and the zone controller, forming a complete audio signal transmission network.
[0070] Although exemplary embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above exemplary embodiments are merely illustrative and are not intended to limit the scope of this application. Various changes and modifications can be made therein by those skilled in the art without departing from the scope and spirit of this application. All such changes and modifications are intended to be included within the scope of this application as claimed in the appended claims.
[0071] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.
[0072] 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 illustrative. For instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another device, or some features may be ignored or not executed.
[0073] The various component embodiments of this application can be implemented in hardware, or as software modules running on one or more processors, or a combination thereof. Those skilled in the art will understand that microprocessors or digital signal processors (DSPs) can be used in practice to implement some or all of the functions of some modules according to the embodiments of this application. This application can also be implemented as an apparatus program (e.g., a computer program and computer program product) for performing part or all of the methods described herein. Such an implementation of this application can be stored on a computer-readable medium, or can be in the form of one or more signals. Such signals can be downloaded from an Internet website, provided on a carrier signal, or provided in any other form.
[0074] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
[0075] Although the description of this application has been made in conjunction with the specific embodiments described above, it will be apparent to those skilled in the art that many substitutions, modifications, and variations can be made based on the foregoing. Therefore, all such substitutions, modifications, and variations are included within the spirit and scope of the appended claims.
Claims
1. An audio signal transmission system, characterized in that, Includes a central computing unit and multiple zone controllers; The central computing unit includes at least a host and a bus master node; The zone controller includes at least bus slave nodes, and each bus slave node is connected in series to the bus master node via an audio bus; The bus master node is used to convert the audio signal generated by the host into a differential signal, which is then transmitted sequentially to each bus slave node through the audio bus; the bus slave node is used to receive the differential signal and drive the local audio device.
2. The audio signal transmission system according to claim 1, characterized in that, The central computing unit also includes a digital signal processor; The digital signal processor is connected to the bus master node and is used to preprocess the audio signal generated by the host.
3. The audio signal transmission system according to claim 1, characterized in that, The zone controller also includes an audio processing circuit; The audio processing circuit is connected to the bus slave node and is used to perform digital-to-analog conversion and / or power amplification on the received differential signal before outputting it to the speaker.
4. The audio signal transmission system according to claim 3, characterized in that, The audio processing circuit is also used to perform analog-to-digital conversion on the analog signals collected by the microphone and then upload them from the node to the host via the bus.
5. The audio signal transmission system according to claim 1, characterized in that, The host is also used to dynamically identify newly connected bus slave nodes and update audio channel mapping relationships when a new zone controller is hot-plugged on the audio bus.
6. The audio signal transmission system according to claim 1, characterized in that, The audio bus provides phantom power to the bus slave nodes.
7. An audio signal transmission method based on the audio signal transmission system as described in any one of claims 1-6, characterized in that, Includes the following steps: The audio signal is generated by the host of the central computing unit and converted into a differential signal through the bus master node; The differential signal is transmitted to the bus slave node of the area controller via the audio bus; Additionally, the audio data is reconstructed from the differential signal by the node via the bus and output to the local audio device.
8. The audio signal transmission method according to claim 7, characterized in that, Before converting the audio signal into a differential signal, the method further includes: The audio signal is preprocessed.
9. The audio signal transmission method according to claim 7, characterized in that, When a new audio device node is connected to the audio bus, the following is included: Register the newly added audio device node in the host, and assign a logical address and update the audio channel mapping relationship for the newly added audio device node.
10. A car, characterized in that, Includes the audio signal transmission system as described in any one of claims 1-6.