Multipath Bluetooth conference system

Abstract

The invention provides a multipath Bluetooth conference system, and belongs to the technical field of audio systems. The system comprises a plurality of receiving ends and a receiving end, the receiving end is in Bluetooth communication connection with a plurality of receiving ends; the receiving end is used for acquiring an audio signal, performing noise reduction processing on the audio signal by using a noise reduction algorithm according to a preset noise reduction parameter, and then sending the audio signal to the receiving end; the receiving end is used for acquiring an audio signal through the receiving end; the processor is also used for adjusting a noise reduction parameter of the receiving end according to the quality and / or noise condition of the Bluetooth transmission audio data so as to reduce the audio loss of the audio signal in the Bluetooth transmission process and / or acquisition process; and the receiver is also used for receiving the noise-reduced audio signal from the receiver and outputting the noise-reduced audio signal. According to the invention, the flexibility of a noise reduction strategy can be improved, data transmission and noise reduction processing parameters are intelligently coordinated, and high quality and intelligence of conference audio processing are guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of audio systems, and in particular relates to a multi-channel Bluetooth conference system. Background Art

[0002] In today's digital communication era, conference systems have become a key tool for remote collaboration and information exchange for enterprises, educational institutions and various organizations. As a mature and widely used short-range wireless communication standard, Bluetooth technology occupies an important position in the field of audio device interconnection. It can realize convenient pairing and data transmission between devices, providing an ideal infrastructure for building wireless conference systems. At the same time, audio noise reduction technology is also constantly developing, from the early simple filtering noise reduction to today's various advanced noise reduction algorithms, such as active noise reduction (ANC) using anti-phase sound waves to offset environmental noise, and call voice noise reduction (CVC) specifically for the echo and environmental noise during the call process to optimize the processing, aiming to provide users with a clear and pure audio experience.

[0003] However, there are still some urgent problems to be solved in the existing conference systems. On the one hand, traditional conference systems often use fixed noise reduction parameter settings, and cannot dynamically adjust the noise reduction strategy according to the actual acoustic environment of different receiving ends. On the other hand, when processing multi-channel Bluetooth audio data, the existing system lacks a deep integration analysis between Bluetooth transmission characteristics and audio noise reduction requirements. When the Bluetooth signal is interfered with, such as when there is an electromagnetic interference source or the signal strength is weakened due to a long distance, audio transmission may have problems such as bit errors and delays. At this time, the existing system cannot intelligently coordinate the priority and parameter settings of Bluetooth data transmission and noise reduction processing. It may aggravate the instability of audio transmission due to excessive pursuit of noise reduction effects, or seriously reduce the audio quality due to ignoring the impact of noise, which greatly affects the fluency and accuracy of conference communication and cannot meet the stringent requirements of modern conferences for high-quality and intelligent audio processing. Summary of the invention

[0004] In view of this, an object of the present invention is to provide a multi-channel Bluetooth conference system to overcome the many deficiencies of the existing conference system in audio processing.

[0005] In order to achieve the above object, the technical solution provided by the present invention is as follows: A multi-channel Bluetooth conference system, comprising: Multiple receivers and receiving ends; the receiving end is connected to the multiple receivers via Bluetooth communication respectively; The receiving end is used to obtain the audio signal, and according to the preset noise reduction parameters, use the noise reduction algorithm to perform noise reduction processing on the audio signal, and then send it to the receiving end; The receiving end is used to obtain an audio signal through a receiving end; it is also used to adjust the noise reduction parameters of the receiving end according to the quality and / or noise conditions of the Bluetooth transmitted audio data to reduce the audio loss of the audio signal during the Bluetooth transmission process and / or collection process; it is also used to receive and output the audio signal after noise reduction processing from the receiving end; the quality of the Bluetooth transmitted audio data is determined according to the Bluetooth connection between the receiving end and the receiving end, and the noise condition of the Bluetooth transmitted audio data is determined according to the audio signal collected by the receiving end.

[0006] Preferably, the receiver is connected to the first audio device via Bluetooth communication; The first audio device is used to collect audio signals and send them to the receiving end or play the audio signals from the receiving end.

[0007] Preferably, the first audio device adopts a QCC3034 chip.

[0008] Preferably, the receiving end adopts CSR8670 chip.

[0009] Preferably, the receiving end is provided with a clear voice capture CVC noise reduction module, which is used to process the echo components in the audio signal and eliminate echo interference through an adaptive filtering algorithm to assist the receiving end in performing audio signal noise reduction processing and transmitting it to the receiving end.

[0010] Preferably, the receiving end is also provided with an active noise reduction (ANC) module, which is used to generate a cancellation signal based on the collected ambient noise signal to reduce the impact of ambient noise on the voice signal, further improving the noise reduction function of the receiving end to ensure the audio quality transmitted to the receiving end.

[0011] Preferably, the receiving end is provided with a selection control module, which is used to switch the audio signal channel according to external instructions or preset rules to control a specific receiving end to obtain the audio signal; the audio signal channel includes a communication channel for the receiving end to realize Bluetooth connection with multiple receiving ends respectively.

[0012] Preferably, the audio signal channel is provided with a default port and a low-level port, and the selection control module selects the audio signal channel through the default port and the low-level port.

[0013] Preferably, the receiving end is connected to the second audio device by wire; The second audio device is used to collect audio signals and send them to the receiving end or play the audio signals from the receiving end.

[0014] Preferably, the second audio device is provided with a USB sound card chip and a USB interface.

[0015] In summary, the present invention provides a multi-channel Bluetooth conference system, including multiple receivers and receiving ends; the receiving end is respectively connected to the multiple receivers by Bluetooth communication; the receiver is used to obtain an audio signal, and according to the preset noise reduction parameters, the audio signal is subjected to noise reduction processing by a noise reduction algorithm, and then sent to the receiving end; the receiving end is used to obtain an audio signal through the receiver; it is also used to adjust the noise reduction parameters of the receiver according to the quality and / or noise conditions of the Bluetooth transmitted audio data, so as to reduce the audio loss of the audio signal during the Bluetooth transmission process and / or the collection process; it is also used to receive and output the audio signal after noise reduction processing from the receiver; the quality of the Bluetooth transmitted audio data is determined according to the Bluetooth connection between the receiving end and the receiver, and the noise conditions of the Bluetooth transmitted audio data are determined according to the audio signal collected by the receiver. The present invention dynamically adjusts the noise reduction parameters according to the Bluetooth connection status and the acoustic environment of the receiver, solves the problem that the fixed parameters of the traditional conference system cannot adapt to different environments, and improves the flexibility of the noise reduction strategy. At the same time, the data transmission and noise reduction processing parameters are intelligently coordinated to avoid audio transmission and quality problems caused by signal interference, and ensure the high quality and intelligence of conference audio processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 It is a structural schematic diagram of a multi-channel Bluetooth conference system; Figure 2 It is a structural diagram of the receiving end; Figure 3 Schematic diagram for selecting an audio signal channel for a control module. DETAILED DESCRIPTION

[0018] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] See also Figure 1 , an embodiment of the present invention provides a multi-channel Bluetooth conference system, including: Multiple receivers and receiving ends; the receiving end is connected to the multiple receivers via Bluetooth communication; The receiving end is used to obtain the audio signal, and according to the preset noise reduction parameters, use the noise reduction algorithm to perform noise reduction processing on the audio signal, and then send it to the receiving end.

[0020] It should be noted that noise reduction parameters refer to some variable values ​​that are pre-set or dynamically adjusted in the noise reduction algorithm. These parameters will affect the degree of suppression and processing of noise components in the audio signal by the noise reduction algorithm. For example, it may include the cutoff frequency of the filter, the value of the gain adjustment, the weight coefficient of the noise reduction algorithm, etc. Different noise reduction parameter settings will make the audio signal present different effects after noise reduction processing. The noise reduction algorithm is an algorithm that identifies, separates and removes the noise contained in the audio signal as much as possible through a specific mathematical model and calculation method. Common noise reduction algorithms include filtering-based, adaptive filtering, spectral subtraction and other types. Its purpose is to improve the clarity of effective components such as speech in the audio signal and reduce the impact of background noise on audio quality.

[0021] The receiving end is used to obtain an audio signal through a receiving end; it is also used to adjust the noise reduction parameters of the receiving end according to the quality and / or noise conditions of the Bluetooth transmitted audio data to reduce the audio loss of the audio signal during the Bluetooth transmission process and / or collection process; it is also used to receive and output the audio signal after noise reduction processing from the receiving end; the quality of the Bluetooth transmitted audio data is determined according to the Bluetooth connection between the receiving end and the receiving end, and the noise condition of the Bluetooth transmitted audio data is determined according to the audio signal collected by the receiving end.

[0022] It should be noted that the quality of audio data transmitted via Bluetooth refers to the quality of audio data transmitted via a Bluetooth wireless communication link, which is affected by multiple factors, such as the strength and stability of the Bluetooth signal, the presence of interference, and the bit error rate of the transmitted data. This quality is determined by a comprehensive analysis of the Bluetooth connection between the receiving end and the receiving end. For example, the quality is better when the signal is strong, the bit error rate is low, and the connection is stable, and vice versa. More specifically, the quality of audio data transmitted via Bluetooth can be evaluated using an audio transmission quality model, the mathematical expression of which is: QAT = w 1× RSSI + w 2× TR + w 3×(1- BER ),in RSSI is the signal strength of the Bluetooth connection, TR is the transmission rate, BER is the bit error rate, w 1. w 2 and w3 are weight parameters. When the quality of Bluetooth audio data transmission QAT When changes occur, such as signal strength weakening or bit error rate increasing, the audio transmission quality model can timely and accurately evaluate the impact of such changes on the overall audio transmission quality. The receiver can adjust relevant strategies based on the calculation results of this model, such as reducing the audio bit rate to adapt to the lower transmission rate, or enhancing error correction coding to reduce the impact of bit error rate on audio quality, thereby optimizing the quality of Bluetooth audio data transmission.

[0023] The noise situation of Bluetooth audio data transmission mainly reflects the additional noise components mixed into the audio data during Bluetooth transmission. This part of the noise may come from electromagnetic interference in the surrounding environment, interference from other signals in the Bluetooth frequency band, etc. Its degree can be determined by analyzing the audio signal collected by the receiving end. For example, abnormal fluctuations in the audio signal and additional noise can reflect the noise situation of Bluetooth audio data transmission. More specifically, the noise situation of Bluetooth audio data transmission can be evaluated using the noise reduction demand model, the mathematical expression of which is: DNR = ɑ × NI + β ×(1- SC ),in NI is the noise level in the Bluetooth audio data transmission. SC For speech clarity, ɑ and β is a weight parameter. When the noise situation of Bluetooth audio data transmission changes, such as the noise intensity increases or new noise frequency components appear, the noise reduction demand model can be used to evaluate the impact of this change on the audio quality and the required noise reduction level. DNR The receiving end can adjust the noise reduction parameters of the receiving end according to the calculation results of this model, such as enhancing the filter's suppression effect on specific noise frequencies, or increasing the overall noise reduction gain to cope with increased noise intensity, thereby reducing audio loss during Bluetooth transmission and ensuring audio quality.

[0024] The receiving end can realize the function of an operational amplifier, that is, multiple input signals are added according to a certain weight or ratio, thereby realizing the synthesis or mixing of audio signals.

[0025] The multi-channel Bluetooth conference system of this embodiment has multiple receivers distributed at different locations on the conference site, and uses the equipped audio acquisition components to collect audio signals in the surrounding environment. These audio signals include the voices of the participants and various background noises. Then, according to the preset noise reduction parameters, the corresponding noise reduction algorithm is used to process the collected audio signals. For example, the filter in the noise reduction algorithm will screen the spectrum of the audio signal according to the set parameters such as the cutoff frequency, suppress the signal components in the noise frequency band, enhance the signal in the frequency band where the voice is located, and preliminarily reduce the noise in the audio signal. Then, the audio signal after noise reduction processing is sent to the receiving end via Bluetooth communication.

[0026] The receiving end dynamically adjusts the noise reduction parameters of the receiving end according to the quality of the collected Bluetooth transmission audio data (such as weak signal and high bit error rate indicating poor quality) and the noise conditions (such as more noise components and high noise intensity) based on the built-in control strategy and algorithm. For example, if the Bluetooth transmission quality is poor, the suppression of high-frequency noise in the noise reduction algorithm of the receiving end may be appropriately increased to reduce the high-frequency noise caused by transmission interference; if the noise conditions show that the ambient noise is large, the noise reduction parameters will be adjusted accordingly to enhance the overall noise reduction effect. Then, the receiving end receives the audio signals from each receiving end after noise reduction processing, and performs further integration, mixing and other processing (if necessary), and finally outputs the audio signal to an external playback device or related applications such as conference recording.

[0027] Different from the traditional conference system that usually adopts fixed noise reduction parameters, this system can dynamically adjust the noise reduction parameters of the receiving end according to the actual quality and noise conditions of Bluetooth audio data transmission. At the same time, it closely combines the Bluetooth transmission characteristics (reflected by quality and noise conditions) with audio noise reduction processing, fully considering the problems of audio signals being easily interfered and generating noise in wireless Bluetooth transmission scenarios. Through intelligent coordination and control at the receiving end, it can achieve the goal of minimizing audio loss and optimizing audio quality while ensuring smooth audio transmission.

[0028] In one embodiment, the receiver is connected to the first audio device via Bluetooth communication; the first audio device is used to collect audio signals and send them to the receiver or play audio signals from the receiver.

[0029] Based on the architecture of the multi-channel Bluetooth conference system, the receiving end extends a Bluetooth connection link with the first audio device. As an external audio source or audio playback terminal, the first audio device interacts with the receiving end through the Bluetooth communication protocol. When audio needs to be collected, the first audio device uses its own audio collection components (such as microphones, etc.) to obtain sound signals, converts them into digital audio data, and sends them to the receiving end in accordance with the Bluetooth transmission specification; conversely, when an audio signal needs to be played, the audio data received by the receiving end is processed and transmitted to the first audio device via Bluetooth, which then plays the audio, thereby realizing the two-way flow of audio signals between the system and external devices.

[0030] In one embodiment, the first audio device uses the QCC3034 chip. The QCC3034 chip is integrated in the first audio device, and realizes the audio function by virtue of its own low-power architecture, powerful processing capability, and support for multiple audio technologies (such as support for high-definition audio coding protocols such as aptX and aptX-HD). In terms of audio acquisition, the high-performance analog and digital audio codecs in the chip perform analog-to-digital conversion on the collected analog audio signals, and then use the processing power of the chip to encode them according to the selected coding protocol and transmit them to the receiver via Bluetooth. When the audio is played, the encoded audio data from the receiver is received, and the audio playback unit is driven to sound after chip decoding and digital-to-analog conversion. At the same time, its integrated CVC headphone noise reduction and echo cancellation technology also helps to improve the audio quality during audio acquisition and playback.

[0031] In one embodiment, the receiving end adopts the CSR8670 chip. The CSR8670 chip plays a core role in the receiving end, relying on its integrated 80MHz programmable Qualcomm Kalimba digital signal processor to process various audio signals. It supports multiple audio codecs such as aptX, aptX low latency, MP3, AAC and SBC, and can perform corresponding encoding conversion on the audio signal collected by the receiving end for subsequent transmission to the receiving end via Bluetooth. At the same time, when receiving audio data from the receiving end or other devices, decoding operations are performed to restore the audio signal. The chip is equipped with multiple interfaces (such as UART, USB2.0, SPI, PCM / I2S, SPDIF, etc.) to facilitate connection and communication with other external devices, and its integrated CVC noise cancellation technology can reduce the interference of environmental noise on voice calls during audio processing. Figure 2 As shown, the receiver can be paired with several Bluetooth headsets, and can be configured with functions such as single-clicking the button to mute the headset MIC and long-pressing the button for 3s to enter the headset connection mode. At the same time, the receiver can display the battery level and connection status of the Bluetooth headset.

[0032] In one embodiment, the receiving end is provided with a clear voice capture CVC noise reduction module, which is used to process the echo components in the audio signal and eliminate echo interference through an adaptive filtering algorithm to assist the receiving end in performing audio signal noise reduction processing and transmitting it to the receiving end.

[0033] After the audio signal enters, the CVC noise reduction module at the receiving end uses an adaptive filtering algorithm to analyze and process the audio signal. It analyzes the frequency spectrum, time domain and other characteristics of the audio signal to distinguish the echo component from the voice and other effective audio components. According to the delay characteristics, correlation and other factors of the echo, the parameters of the echo signal are estimated, and then a cancellation signal with the same size and opposite phase as the echo signal is generated. The cancellation signal is added to the original audio signal to eliminate the echo component, reduce echo interference, assist the noise reduction processing process of the entire receiving end, and finally send the processed audio signal to the receiving end.

[0034] In one embodiment, the receiving end is also provided with an active noise reduction (ANC) module, which is used to generate a cancellation signal based on the collected ambient noise signal to reduce the impact of ambient noise on the voice signal, further improving the noise reduction function of the receiving end to ensure the audio quality transmitted to the receiving end.

[0035] The ANC noise reduction module relies on the built-in reference microphone to collect the ambient noise signals around the receiver in real time, and conducts detailed analysis of these collected noise signals, including obtaining key parameters such as frequency, amplitude and phase. Then, based on these parameters, a cancellation signal with the same frequency and amplitude as the ambient noise signal but opposite phase is generated. During the audio signal transmission process, this cancellation signal is superimposed on the audio signal so that the ambient noise signal is actively cancelled, thereby reducing the impact of ambient noise on the voice signal, improving the noise reduction function of the receiver, and ensuring that the audio quality transmitted to the receiving end is improved.

[0036] In one embodiment, the receiving end is provided with a selection control module, which is used to switch the audio signal channel according to external instructions or preset rules to control a specific receiving end to obtain the audio signal; the audio signal channel includes a communication channel for the receiving end to realize Bluetooth connection with multiple receiving ends respectively.

[0037] The selection control module of the receiving end monitors external instructions (such as selection instructions issued by the user through the operation interface) or controls the Bluetooth connection communication channels (i.e., audio signal channels) established between the receiving end and multiple receiving ends according to preset rules (such as the fixed audio input order set according to the meeting arrangement, etc.). When it is necessary to select the audio signal of a specific receiving end, the module switches to the corresponding audio signal channel through the corresponding control logic operation, so that the audio signal of the target receiving end can be smoothly transmitted to the receiving end, while blocking the audio signal transmission of other non-selected receiving ends, so as to achieve accurate selection of the audio signal source. The Bluetooth version of the receiving end can be set to V5.0; the transmission frequency is 2.4G~2.48G; the Bluetooth protocols include HSP, HFP, A2DP and AVRCP; the audio decoding includes APTX and SBC; the transmission power is CLASS 1; the working current of Bluetooth calls is 80mA.

[0038] In one embodiment, the audio signal channel is provided with a default port and a low-level port, and the selection control module selects the audio signal channel through the default port and the low-level port.

[0039] A default port and a low-level port are configured on each audio signal channel (i.e., the Bluetooth connection communication channel between the receiving end and each receiving end), and the select control module realizes the channel selection function by operating the level status of these ports. For example, under normal conditions, the default port maintains a certain default level to ensure that the corresponding audio signal channel is in a default working or non-working state; when the select control module receives a selection instruction and needs to switch the audio signal channel, the level status of the low-level port of the corresponding channel is changed (such as from a high level to a low level or vice versa), thereby changing the conduction status of the channel, thereby realizing the selection of a specific audio signal channel and controlling the transmission path of the audio signal.

[0040] like Figure 3 As shown, taking the 4-channel audio transmission channels BT1-4 as an example, each channel sets the default PIO1 and the low-level PIO2 respectively. The receiving end controls whether the sound of the corresponding receiving end is transmitted to the non-selected receiving end through the different designs of the two ports, thereby achieving stable sound transmission.

[0041] In one embodiment, the receiving end is connected to the second audio device via a wire; the second audio device is used to collect audio signals and send them to the receiving end or play audio signals from the receiving end.

[0042] The receiving end establishes a connection link with the second audio device through a suitable wired connection method (such as a USB cable, audio cable, etc.). When audio needs to be collected, the second audio device uses its own audio collection component to obtain the sound signal, converts it into a corresponding electrical signal (analog or digital form, depending on the device and connection method), and transmits it to the receiving end along the wired line; when audio needs to be played, the receiving end sends the processed audio signal to the second audio device through a wired connection, and the second audio device plays the audio, thus realizing stable and reliable audio data interaction between the receiving end and the external second audio device.

[0043] In one embodiment, the second audio device is provided with a USB sound card chip and a USB interface.

[0044] The USB sound card chip integrated inside the second audio device is responsible for processing the core audio processing functions such as analog-to-digital conversion, digital-to-analog conversion, and audio encoding and decoding of audio signals. During audio acquisition, the USB interface receives analog audio signals from external audio acquisition devices (such as microphones), and the USB sound card chip converts them into digital audio data and performs necessary encoding processing; during audio playback, the encoded audio data from the receiving end and other devices is received, decoded by the chip, and converted into analog audio signals, which are then output to the audio playback unit (such as speakers) through the USB interface for sound. At the same time, the USB interface, as a universal data transmission interface, facilitates the connection and communication between the device and other external devices (such as computers, mobile phones, etc.), and realizes the sharing and interaction of audio data. The USB sound card chip can use the CM6533X1 chip, which has high compatibility and can be adapted to different speaker products.

[0045] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multi-channel Bluetooth conference system, characterized in that: include: A plurality of receivers and receiving ends; the receiving end is respectively connected to the plurality of receivers via Bluetooth communication; The receiving end is used to obtain an audio signal, and according to a preset noise reduction parameter, use a noise reduction algorithm to perform noise reduction processing on the audio signal, and then send it to the receiving end; The receiving end is used to obtain the audio signal through the receiving end; It is also used to adjust the noise reduction parameters of the receiving end according to the quality and / or noise conditions of the Bluetooth transmitted audio data, so as to reduce the audio loss of the audio signal during the Bluetooth transmission process and / or collection process; it is also used to receive the audio signal after noise reduction processing from the receiving end and output it; the quality of the Bluetooth transmitted audio data is determined according to the Bluetooth connection between the receiving end and the receiving end, and the noise condition of the Bluetooth transmitted audio data is determined according to the audio signal collected by the receiving end.

2. A multi-channel Bluetooth conference system according to claim 1, characterized in that: The receiving end is connected to the first audio device via Bluetooth communication; The first audio device is used to collect the audio signal and send it to the receiving end or play the audio signal from the receiving end.

3. A multi-channel Bluetooth conference system according to claim 2, characterized in that: The first audio device adopts the QCC3034 chip.

4. A multi-channel Bluetooth conference system according to claim 3, characterized in that: The receiving end adopts CSR8670 chip.

5. A multi-channel Bluetooth conference system according to claim 1, characterized in that: The receiving end is provided with a clear voice capture CVC noise reduction module, which is used to process the echo components in the audio signal and eliminate echo interference through an adaptive filtering algorithm to assist the receiving end in performing audio signal noise reduction processing and transmitting it to the receiving end.

6. A multi-channel Bluetooth conference system according to claim 5, characterized in that: The receiving end is also provided with an active noise reduction (ANC) noise reduction module, which is used to generate a cancellation signal according to the collected ambient noise signal to reduce the impact of ambient noise on the voice signal, further improving the noise reduction function of the receiving end to ensure the audio quality transmitted to the receiving end.

7. A multi-channel Bluetooth conference system according to claim 1, characterized in that: The receiving end is provided with a selection control module, which is used to switch the audio signal channel according to external instructions or preset rules to control the specific receiving end to obtain the audio signal; the audio signal channel includes the communication channel for the receiving end to realize Bluetooth connection with multiple receiving ends respectively.

8. A multi-channel Bluetooth conference system according to claim 7, characterized in that: The audio signal channel is provided with a default port and a low-level port, and the selection control module selects the audio signal channel through the default port and the low-level port.

9. A multi-channel Bluetooth conference system according to claim 1, characterized in that: The receiving end is connected to the second audio device by wire; The second audio device is used to collect the audio signal and send it to the receiving end or play the audio signal from the receiving end.

10. A multi-channel Bluetooth conference system according to claim 9, characterized in that: The second audio device is provided with a USB sound card chip and a USB interface.

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