5.8G wireless multi-channel audio transmission system

Abstract

The application discloses a 5.8G wireless multi-channel audio transmission system, and belongs to the technical field of wireless audio transmission, which comprises a transmitting end module and a receiving end module. The transmitting end module is provided with: an IIS input module for acquiring multi-channel original PCM data; a lossless compression and encoding module for performing parallel lossless compression; an interference detection and frequency hopping module for detecting the packet loss rate of environmental interference, selecting the optimal channel based on an interference scoring formula and adaptively hopping frequency; and a radio frequency transmitting module for packaging and transmitting data packets. The receiving end module is provided with: a radio frequency receiving module for receiving data packets; a bidirectional data exchange module for reporting link status; a lossless decoding module for restoring PCM data; and an IIS output module for outputting audio. The application further comprises an ASRC module for eliminating clock deviation and a sound mixing processing module for preventing overflow. The system supports 10-channel 48kHz / 24bit high-definition transmission at most, is strong in anti-interference, low in time delay and suitable for wireless television sound, a soundbar and a multimedia sound system.

Description

Technical Field

[0001] This invention relates to the field of wireless audio transmission technology, and in particular to a 5.8G wireless multi-channel audio transmission system. Background Technology

[0002] Wireless audio transmission technology is widely used in consumer electronics, such as wireless headphones and wireless speakers. Existing wireless audio transmission solutions are mostly based on Bluetooth or proprietary protocols in the 2.4GHz band. However, these existing technologies generally suffer from the following problems:

[0003] Traditional technologies typically only support 2-channel (stereo) transmission, which cannot meet the needs of 5.1, 7.1 or even more channels in home theaters or soundbar systems, resulting in a poor surround sound experience.

[0004] The 2.4GHz band is congested with devices (Wi-Fi, Bluetooth, microwave ovens, etc.), which can easily lead to channel conflicts and cause problems such as stuttering, dropouts, and noise in audio transmission. In particular, in complex environments with multiple devices, it is difficult to guarantee playback continuity.

[0005] To achieve multi-channel transmission, existing technologies often require sacrificing audio quality (such as reducing sampling rate / bit depth) or increasing compression latency, making it difficult to simultaneously meet the requirements of 48kHz / 24bit high-definition audio and ultra-low latency.

[0006] In a multi-channel environment, maintaining the synchronization accuracy between channels and the dynamic range during audio mixing are technical challenges. Existing solutions are prone to overflow distortion or harsh sound.

[0007] Therefore, there is an urgent need for a wireless audio transmission system that can support multi-channel audio, strong anti-interference capabilities, high-definition audio quality, and ultra-low latency.

[0008] The information disclosed in this background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0009] The purpose of this invention is to provide a wireless audio transmission system that supports multi-channel audio, strong anti-interference, high-definition audio quality, and ultra-low latency.

[0010] To achieve the above objectives, the present invention provides the following solution: A 5.8V wireless multi-channel audio transmission system, comprising: The transmitter module further includes: The IIS input module is used to obtain multi-channel raw PCM audio data from the IIS bus. The lossless compression encoding module is used to perform lossless compression encoding on the multi-channel raw PCM audio data to generate compressed audio frames; The interference detection and frequency hopping module is used to perform wireless environment interference detection, obtain the interference intensity of each channel in the current working frequency band and the packet loss rate data fed back by the receiver, and determine the optimal transmission channel based on the interference intensity and packet loss rate data and a preset frequency modulation algorithm. The radio frequency transmission module is used to encapsulate the compressed audio frame into radio frequency data packets and transmit them through the optimal transmission channel using a proprietary protocol in the 5.8 GHz band. The receiver module further includes: An RF receiving module is used to receive the RF data packets via a 5.8GHz RF circuit; The bidirectional data exchange module is used to exchange data bidirectionally with the transmitter module and report local packet loss and wireless interference detection results in the environment. The lossless decoding module is used to perform lossless decoding on the received radio frequency data packets and restore them to the original multi-channel PCM audio data; The IIS output module is used to output decoded multi-channel raw PCM audio data via the IIS bus.

[0011] Optionally, the detection and frequency hopping module performs wireless environmental interference detection, specifically including: Scan the M available channels within the 5.8 GHz band and measure the Received Signal Strength Indication (RSSI) for each channel i. i and background noise i The interference score is calculated according to the following formula. i :

[0012] Among them, RSSI max To maximize the received signal strength, Noise max To represent the maximum background noise, w1 and w2 are preset weighting coefficients, and w1+w2=1. Selecting Interference i The smallest channel is used as the initial working channel.

[0013] Optionally, the preset frequency modulation algorithm includes: Set the packet loss rate threshold P loss-thresh With interference intensity threshold I thresh ; When the real-time packet loss rate P reported by the receiving end loss-real >P loss-thresh Or the real-time interference strength I of the current channel real>I thresh When this occurs, frequency hopping is triggered; Interference score value is selected from the candidate channel set. i The lowest-ranking channel that is not recorded in the blacklist will be used as the new working channel; After frequency hopping, record the original channel to the blacklist and set a cooldown time T. cool .

[0014] Optionally, the lossless compression encoding employs adaptive differential pulse code modulation or subband coding algorithms to perform parallel compression on multiple channels, wherein the compression ratio R... comp satisfy:

[0015] B original B represents the number of bits in the original PCM data. compressed R is the number of bits in the compressed data. comp ≤0.5.

[0016] Optionally, the transmitter module further includes an adaptive software ASRC module, configured as follows: Detect the frequency deviation Δf between the transmitter's master clock and the receiver's slave clock; Based on the frequency deviation Δf, the sampling rate conversion ratio ASRC is calculated. ratio :

[0017] in f stx The sampling clock frequency of the transmitter. f srx The clock frequency recovered by the receiving end; When ASRC ratio When the value is ≠ 1, perform linear interpolation or Lagrange interpolation resampling on the audio data to eliminate clock asynchronous overflow or underload.

[0018] Optionally, the receiving module further includes a mixing processing module for preventing overflow and maintaining dynamic range during multi-channel combined output, wherein its mixed output sample y[n] is calculated by the following formula:

[0019] Where K is the total number of audio channels, x k[n] is the value of the nth sample point in the kth channel, and D is the preset dynamic adjustment coefficient.

[0020] Optionally, the lossless decoding module adopts the LC3plus audio decoding standard to achieve high-definition audio encoding and decoding with a sampling rate of 48kHz and a bit depth of 24bit, and the encoding and decoding algorithm delay does not exceed 5ms.

[0021] Optionally, the multi-channel raw PCM audio data supports up to 10 independent channels, each channel having a data format of 48kHz / 24bit, and the channels are synchronized through a timestamp mechanism with a synchronization error of less than one PCM sampling period.

[0022] Optionally, the radio frequency data packet includes a synchronization word, a packet header, a channel identifier, a timestamp, a compressed audio payload, and a cyclic redundancy check field; wherein, the channel identifier field is used to distinguish data from different channels, and the timestamp field is used by the receiving end to perform multi-channel realignment.

[0023] Optionally, the bidirectional data exchange between the transmitting module and the receiving module is achieved through a low-rate feedback channel in the 5.8GHz band. This feedback channel is independent of the audio data channel and is used to transmit ACK / NACK confirmations, packet loss rate statistics, receiving interference detection reports, and transmit power control commands.

[0024] Compared with the prior art, the present invention has the following beneficial effects: This invention provides a 5.8G wireless multi-channel audio transmission system, achieving significant technological advancements through the collaborative operation of the transmitter and receiver modules. The system employs a modular architecture including IIS input, lossless compression encoding, interference detection and frequency hopping, RF transceiver, bidirectional data exchange, lossless decoding, and IIS output. It supports high-definition wireless audio transmission of up to 10 independent channels, each in 48kHz / 24bit format, overcoming the technical bottleneck of traditional wireless audio systems that only support two channels and have limited sound quality. Through an interference scoring mechanism that comprehensively evaluates the signal strength and noise floor of each channel, and an adaptive frequency hopping algorithm based on packet loss rate and interference threshold, the system can dynamically select the optimal working channel and quickly avoid interference, effectively preventing audio interruptions and ensuring playback continuity and stability. Utilizing efficient lossless compression and LC3plus encoding / decoding technology, it achieves ultra-low latency transmission while ensuring complete restoration of the original audio information. Furthermore, the adaptive ASRC module in the system can eliminate clock frequency deviations between the transmitter and receiver, preventing data overflow or underload during long-term playback; the mixing module prevents signal clipping during multi-channel merging through dynamic normalization, while maintaining the dynamic range of the audio for a more natural and full listening experience. Overall, this invention has outstanding advantages such as multi-channel support, strong anti-interference, high-definition sound quality, ultra-low latency, clock robustness, and natural mixing, making it particularly suitable for wireless TV speakers, wireless soundbars, and home multimedia audio systems. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 A schematic diagram of the module structure of a 5.8G wireless multi-channel audio transmission system provided in an embodiment of the present invention.

[0027] Figure 2 This is a flowchart illustrating the steps of the 5.8 wireless multi-channel audio transmission method provided in an embodiment of the present invention. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] The purpose of this invention is to provide a wireless audio transmission system that supports multi-channel audio, strong anti-interference, high-definition audio quality, and ultra-low latency.

[0030] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] Example 1: This embodiment uses an 8-channel, 48kHz / 24bit wireless soundbar as an example for illustration.

[0032] like Figure 1 As shown, this embodiment provides a 5.8G wireless multi-channel audio transmission system, which includes a transmitter module and a receiver module.

[0033] The transmitter module specifically includes the following modules: IIS Input Module: Connects to an audio source (such as an optical or HDMI audio output from a TV) and receives 8 channels of raw PCM audio data via the IIS bus. Each channel is formatted with a 48kHz sampling rate and a 24-bit bit depth, and the data stream is time-division multiplexed.

[0034] Lossless compression encoding module: Connected to the IIS input module, it uses a parallel sub-band encoding algorithm to simultaneously perform lossless compression on PCM data from all 8 channels. In this embodiment, the compression ratio is...R comp = B compressed / B original By keeping the value around 0.45, the compressed data size is less than half that of the original data, effectively reducing the wireless transmission bandwidth requirements.

[0035] Interference detection and frequency hopping module: This module periodically (e.g., every 100ms) scans the five available channels within the 5.8GHz band. For each channel i, it measures the Received Signal Strength Indicator (RSSI). i and background noise i (Unit: dBm). Calculate the interference score using the following formula:

[0036] Among them, RSSI max Take -20dBm, Noise max Using -80dBm, weighting coefficients w1=0.6 and w2=0.4. Interference is then selected after calculation. i The channel with the lowest loss is used as the initial operating channel. Simultaneously, this module obtains the packet loss rate reported by the receiver in real time through a bidirectional data exchange module. A packet loss rate threshold P is set. loss-thresh =5%, Interference strength threshold I thresh =0.7. When the real-time packet loss rate exceeds 5% or the interference score of the current channel exceeds 0.7, frequency hopping is triggered: the channel with the lowest interference score and not in the blacklist is selected from the candidate channels as the new working channel, and the original channel is added to the blacklist. A cooldown time T is set. cool =30 seconds.

[0037] Adaptive ASRC module: Detects the frequency deviation Δf between the transmitter's master clock (e.g., 48.000kHz generated by a crystal oscillator) and the receiver's slave clock (recovered via a feedback channel, e.g., 47.985kHz). Calculates the sampling rate conversion ratio.

[0038] Due to ASRC ratio ≠1. This module performs cubic spline interpolation resampling on the audio data, converting the data stream at the transmitting end into a data stream that matches the clock at the receiving end, preventing the receiving end buffer from overflowing or underflowing after long-term playback.

[0039] The radio frequency (RF) transmission module encapsulates the compressed audio frames into RF data packets. The data packet structure is as follows: synchronization word (4 bytes, 0x5A5A5A5A), packet header (1 byte, indicating the packet type is audio data), channel identifier (1 byte, 0x01~0x08 corresponding to 8 channels), timestamp (4 bytes, increasing in units of sampling periods), compressed audio payload (maximum 256 bytes), and CRC32 checksum (4 bytes). Finally, this module transmits the data packets into the air via a 5.8GHz antenna using a proprietary protocol.

[0040] The receiver module specifically includes the following modules: RF receiver module: Receives radio frequency data packets from the air via a 5.8GHz antenna, performs demodulation, descrambling, synchronization word detection, and CRC check. If the check fails, the packet is discarded and the packet loss event is recorded.

[0041] The bidirectional data receiving module communicates with the interference detection and frequency hopping module at the transmitting end via a dedicated low-rate feedback channel within the 5.8 GHz band (e.g., sending a control frame every 10 ms). This module reports the following: ACK / NACK confirmations for each received data packet, packet loss rate based on sequence number gap statistics (e.g., the percentage of packets lost in the past second), interference intensity reports for each channel obtained from the receiver's own scan, and suggested transmit power adjustment values.

[0042] The lossless decoding module uses the LC3 plus decoder to decode the verified compressed audio payload, restoring it to 48kHz / 24bit PCM audio data. In this embodiment, the total latency of the encoding / decoding algorithm is controlled within 4.5ms, meeting ultra-low latency requirements. During decoding, the data for each channel is distributed to the corresponding output channel based on the channel identifier field in the data packet.

[0043] Mixing module: When it is necessary to downmix 8-channel raw data into 2-channel stereo output (e.g., to drive the left and right speakers of a soundbar), this module performs mixing calculations for each sample point n. The mixed output sample point y[n] is given by the following formula:

[0044] Where K=8, x k [ n ] represents the nth sample value of the kth channel (normalized range [-1, 1]), and D is a preset dynamic adjustment coefficient, which is set to D=32 in this embodiment. This formula can automatically attenuate the gain to prevent overflow clipping when the signal is large; and maintain the original amplitude approximately when the signal is small, thereby maintaining the dynamic range and making the sound of the mixed audio natural.

[0045] IIS Output Module: Outputs the mixed PCM audio data to the subsequent digital power amplifier or DAC chip via the IIS bus to drive the speakers to produce sound.

[0046] like Figure 2 As shown, this embodiment also provides a 5.8G wireless multi-channel audio transmission method based on the above system, including a transmitter process (steps S101~S105) and a receiver process (S201~S205): Transmitter process: S101: Obtains multi-channel raw PCM audio data from the IIS bus via the IIS input module.

[0047] S102: The lossless compression encoding module performs lossless compression encoding on multiple channels in parallel to generate compressed audio frames.

[0048] S103: The interference detection and frequency hopping module detects environmental wireless interference and packet loss reported by the receiver. Combining the interference scoring formula and frequency hopping algorithm (threshold comparison, blacklist mechanism), it determines whether to hop the frequency and selects the optimal channel.

[0049] 104: The compressed audio frame is encapsulated into an RF data packet containing channel identifiers and timestamps via the RF transmission module.

[0050] S105: Transmits radio frequency data packets into the air via a selected 5.8 GHz channel.

[0051] Receiver process: S201: Receive radio frequency data packets in the air through the radio frequency receiving module.

[0052] S202: Exchanges data with the transmitter through the bidirectional data exchange module, and reports local packet loss and environmental wireless interference test results.

[0053] S203: The lossless decoding module performs lossless decoding of radio frequency data packets and uses the ASRC module to adaptively compensate for clock deviations, restoring them to PCM audio data.

[0054] S204: The mixing processing module performs mixing calculations on the decoded multi-channel PCM data to prevent overflow and maintain dynamic range.

[0055] S205: Outputs processed multi-channel raw PCM audio data to the playback device via the IIS output module.

[0056] Through the above specific implementation methods, the present invention has indeed achieved wireless transmission with support for up to 10 channels, 48kHz / 24bit high-definition audio, strong anti-interference, and ultra-low latency in the 5.8GHz frequency band, and can be reliably applied to wireless TV speakers, wireless soundbars, and home multimedia audio systems.

[0057] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the systems disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple; relevant parts can be referred to the method section.

[0058] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A 5.8V wireless multi-channel audio transmission system, characterized in that, include: The transmitter module further includes: The IIS input module is used to obtain multi-channel raw PCM audio data from the IIS bus. The lossless compression encoding module is used to perform lossless compression encoding on the multi-channel raw PCM audio data to generate compressed audio frames; The interference detection and frequency hopping module is used to perform wireless environment interference detection, obtain the interference intensity of each channel in the current working frequency band and the packet loss rate data fed back by the receiver, and determine the optimal transmission channel based on the interference intensity and packet loss rate data and a preset frequency modulation algorithm. The radio frequency transmission module is used to encapsulate the compressed audio frame into radio frequency data packets and transmit them through the optimal transmission channel using a proprietary protocol in the 5.8 GHz band. The receiver module further includes: An RF receiving module is used to receive the RF data packets via a 5.8GHz RF circuit; The bidirectional data exchange module is used to exchange data bidirectionally with the transmitter module and report local packet loss and wireless interference detection results in the environment. The lossless decoding module is used to perform lossless decoding on the received radio frequency data packets and restore them to the original multi-channel PCM audio data; The IIS output module is used to output decoded multi-channel raw PCM audio data via the IIS bus.

2. The 5.8V wireless multi-channel audio transmission system according to claim 1, characterized in that, The detection and frequency hopping module performs wireless environment interference detection, specifically including: Scan the M available channels within the 5.8 GHz band and measure the Received Signal Strength Indication (RSSI) for each channel i. i and background noise i The interference score is calculated according to the following formula. i : Among them, RSSI max To maximize the received signal strength, Noise max To represent the maximum background noise, w1 and w2 are preset weighting coefficients, and w1+w2=1. Selecting Interference i The smallest channel is used as the initial working channel.

3. The 5.8V wireless multi-channel audio transmission system according to claim 1, characterized in that, The preset frequency modulation algorithm includes: Set the packet loss rate threshold P loss-thresh With interference intensity threshold I thresh ; When the real-time packet loss rate P reported by the receiving end loss-real >P loss-thresh Or the real-time interference strength I of the current channel real >I thresh When this occurs, frequency hopping is triggered; Interference score value is selected from the candidate channel set. i The lowest-ranking channel that is not recorded in the blacklist will be used as the new working channel; After frequency hopping, record the original channel to the blacklist and set a cooldown time T. cool .

4. The 5.8V wireless multi-channel audio transmission system according to claim 1, characterized in that, The lossless compression encoding employs adaptive differential pulse code modulation or sub-band encoding algorithms to perform parallel compression of multiple audio channels, where the compression ratio R... comp satisfy: B original B represents the number of bits in the original PCM data. compressed R is the number of bits in the compressed data. comp ≤0.

5.

5. The 5.8 wireless multi-channel audio transmission system according to claim 1, characterized in that, The transmitter module also includes an adaptive software ASRC module, configured as follows: Detect the frequency deviation Δf between the transmitter's master clock and the receiver's slave clock; Based on the frequency deviation Δf, the sampling rate conversion ratio ASRC is calculated. ratio : in f stx The sampling clock frequency of the transmitter. f srx The clock frequency recovered by the receiving end; When ASRC ratio When the value is ≠ 1, perform linear interpolation or Lagrange interpolation resampling on the audio data to eliminate clock asynchronous overflow or underload.

6. The 5.8V wireless multi-channel audio transmission system according to claim 1, characterized in that, The receiving module also includes a mixing module to prevent overflow and maintain dynamic range during multi-channel combined output. Its mixing output sample y[n] is calculated by the following formula: Where K is the total number of audio channels, x k[n] is the value of the nth sample point in the kth channel, and D is the preset dynamic adjustment coefficient.

7. The 5.8V wireless multi-channel audio transmission system according to claim 1, characterized in that, The lossless decoding module adopts the LC3plus audio decoding standard to achieve high-definition audio encoding and decoding with a sampling rate of 48kHz and a bit depth of 24bit, and the encoding and decoding algorithm latency does not exceed 5ms.

8. The 5.8V wireless multi-channel audio transmission system according to claim 1, characterized in that, The multi-channel raw PCM audio data supports up to 10 independent channels, each channel is in 48kHz / 24bit format, and the channels are synchronized through a timestamp mechanism with a synchronization error of less than one PCM sampling period.

9. The 5.8V wireless multi-channel audio transmission system according to claim 1, characterized in that, The radio frequency data packet includes a synchronization word, packet header, channel identifier, timestamp, compressed audio payload, and cyclic redundancy check field; wherein, the channel identifier field is used to distinguish data from different channels, and the timestamp field is used by the receiver to perform multi-channel realignment.

10. The 5.8V wireless multi-channel audio transmission system according to claim 1, characterized in that, The bidirectional data exchange between the transmitter module and the receiver module is achieved through a low-rate feedback channel in the 5.8GHz band. This feedback channel is independent of the audio data channel and is used to transmit ACK / NACK confirmations, packet loss rate statistics, receiver interference detection reports, and transmit power control commands.

Images