Mobile phone auxiliary type intelligent interphone and implementation method thereof
By adopting CNN noise reduction model and wireless communication module in mobile phone assisted intelligent intercom, the obstacles between intercom and mobile phones in audio processing and adaptation are solved, and high-quality voice communication and data transmission are achieved.
Patent Information
- Application Number
- CN202510021585.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-07
- Publication Date
- 2025-03-14
AI Technical Summary
There are obstacles such as audio processing and adaptation when used with mobile phones, making it difficult for the two to achieve seamless docking and coordinated work.
A mobile phone assisted intelligent walkie-talkie is designed, using a combination of mobile phone components and walkie-talkie end components to process digital audio signals through the CNN noise reduction model in the audio processing chip, and uses wireless communication modules and connection modules for data transmission and adaptation.
The CNN noise reduction model removes background noise, improves speech clarity and intelligibility, and ensures communication quality in noisy environments. At the same time, the audio processing chip performs gain adjustment and data compression, optimizing audio effects and transmission efficiency.
Smart Images
Figure CN119628674A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the field of intercoms, in particular to a mobile phone-assisted intelligent intercom and a realization method thereof. Background Art
[0002] In many industries, such as logistics, security, and construction, walkie-talkies are essential communication tools. These industries usually require a large number of walkie-talkie devices, so cost is an important consideration. At the same time, consumers are increasingly paying attention to cost-effectiveness when purchasing walkie-talkies for personal use; reducing the cost of walkie-talkies while maintaining or improving their functions can meet the market's price-sensitive needs; with the diversification of people's work and life scenes, the portability and versatility of communication equipment are increasingly required. For example, outdoor enthusiasts want to carry lighter communication equipment when exploring the wild; event organizers need a communication tool that can not only meet on-site communication needs, but also can be easily integrated with other devices (such as mobile phones) to achieve more functions (such as data sharing, remote command, etc.).
[0003] Existing walkie-talkies have obstacles such as audio processing and adaptation when used with mobile phones, making it difficult for the two to achieve seamless docking and collaborative work.
[0004] Therefore, those skilled in the art have proposed a mobile phone-assisted intelligent intercom and an implementation method thereof to solve the problems raised by the background technology. Summary of the invention
[0005] In order to solve the above technical problems, the present invention provides a mobile phone-assisted intelligent intercom and an implementation method thereof, so as to solve the problems such as audio processing and adaptation obstacles existing in the prior art when the intercom is used in conjunction with a mobile phone.
[0006] A mobile phone-assisted intelligent intercom and implementation method thereof, comprising: a mobile phone end component, which includes a central processing unit, an audio processing chip, a first connection module, a speaker and a microphone;
[0007] The walkie-talkie end component includes a main control chip, a wireless communication module, a second connection module and a power management module; the wireless communication module has a built-in radio frequency transceiver chip, data is transmitted between the second connection module and the first connection module, and the audio processing chip uses a CNN noise reduction model to process digital audio signals.
[0008] Preferably, the CNN denoising model is as follows:
[0009] The input noisy speech signal is x(n), and after short-time Fourier transform, the frequency domain representation X(k,f) is obtained, where k represents the time frame index and f represents the frequency index;
[0010] The CNN denoising model is represented by the function F CNN , the frequency domain signal after noise reduction is Y(k,f)=F CNN (X(k,f)); obtain the de-noised speech signal y(n) through inverse short-time Fourier transform;
[0011] For the first layer of the convolutional layer, the input feature map is A l-1 (k,f), the convolution kernel is W l , with a bias of b l , then the output feature map A l The calculation formula for (k,f) is:
[0012] A l (k,f)=σ(Σ i,j W l (i,j)A l-1 (ki,fj)+b l );
[0013] Where σ is the activation function, which uses the ReLU function.
[0014] The specific steps of applying the CNN noise reduction model to the audio processing chip for noise reduction are as follows:
[0015] Digital audio signals are framed and windowed;
[0016] Hamming window Where N is the window length, n = 0, 1, ..., N-1);
[0017] Then a short-time Fourier transform is performed to convert the audio signal into the frequency domain to obtain a time-frequency representation;
[0018] The time-frequency representation is used as the input of the CNN denoising model, and the denoised frequency domain signal is obtained after being processed by the model; the denoised frequency domain signal is then converted back to the time domain through the inverse short-time Fourier transform to obtain the denoised digital audio signal, and then subsequent compression encoding and transmission operations are performed.
[0019] Preferably, the microphone converts the input sound into an analog audio signal and transmits it to the audio processing chip; the audio processing chip converts the analog audio signal into digital audio data, and performs noise reduction and gain adjustment; the main control chip receives the digital audio data, unpacks and verifies it, and transmits it to the wireless communication module, and the wireless communication module modulates the unpacked audio data into a radio frequency signal and transmits it through an antenna to communicate with other walkie-talkies.
[0020] Preferably, after receiving the audio data from other walkie-talkies, the wireless communication module demodulates it into digital audio data and transmits it to the main control chip, which adds verification and then transmits the data to the second connection module; the second connection module sends the audio data to the first connection module; the audio data is then transmitted to the audio processing chip via the first connection module and restored to an analog audio signal, which is played through a speaker.
[0021] Preferably, the audio processing chip uses Opus algorithm to perform data compression; when the digital audio data received by the main control chip is compressed data, it is restored to the original audio format through decoding and then transmitted to the wireless communication module.
[0022] Preferably, the main control chip sets the frequency and power of the radio frequency signal during the communication process to ensure the communication quality and distance.
[0023] Preferably, the first connection module and the second connection module are both USB connection modules.
[0024] Preferably, the mobile phone end component charges the intercom end component via a USB connection; the power management module has a built-in step-down circuit and a filter circuit, and the power management module monitors the charging status in real time.
[0025] Preferably, the first connection module and the second connection module further include a WIFI module and a Bluetooth module.
[0026] A method for implementing a mobile phone-assisted intelligent intercom, comprising:
[0027] S1. Preparation for audio processing and transmission on mobile phone:
[0028] The microphone captures external sounds and converts them into analog audio signals and transmits them to the audio processing chip; after the audio processing chip converts them into digital audio, it uses the CNN noise reduction model to remove noise and perform gain adjustment, uses the Opus algorithm to compress the audio data, and finally sends the processed data to the first connection module;
[0029] S2. Data transmission from mobile phone to intercom:
[0030] The first connection module sends the data to the second connection module according to the selected connection mode, and the second connection module sends the data to the main control chip. After receiving the data, the main control chip unpacks and verifies, decodes and restores the compressed data, and then transmits it to the wireless communication module;
[0031] S3. Intercom communication and data return:
[0032] The RF transceiver chip modulates the audio data into a RF signal and transmits it through the antenna to achieve communication with other walkie-talkies. During this period, the main control chip will adjust the frequency and power of the RF signal to ensure communication; when receiving audio data from other walkie-talkies, the wireless communication module demodulates and transmits it to the main control chip, which adds verification and sends it back to the first connection module on the mobile phone through the second connection module;
[0033] S4, mobile audio playback:
[0034] The first connection module receives the data and sends it to the audio processing chip. The audio processing chip restores the digital audio data to an analog audio signal and plays it through the speaker.
[0035] Compared with the prior art, the present invention has the following beneficial effects:
[0036] The present invention processes digital audio signals through the CNN noise reduction model, which can accurately identify and remove various complex background noises, restore clear voice signals, greatly improve the clarity and intelligibility of voice, ensure that both parties in communication can accurately convey information in a noisy environment, and effectively solve the problem of poor voice quality caused by noise interference in traditional cooperation methods; the audio processing chip can also adjust the gain of the audio signal, so that the voice can maintain a suitable volume and sound quality in different environments and communication distances, further optimize the audio effect, enhance the user's auditory experience, and avoid the situation where the communication effect is affected by uneven volume or too small or too large volume. BRIEF DESCRIPTION OF THE DRAWINGS
[0037] Figure 1 It is a schematic diagram of the overall structure of the present invention;
[0038] In the figure:
[0039] 1. Mobile phone component; 101. Central processing unit; 102. Audio processing chip; 103. First connection module; 104. Speaker; 105. Microphone; 2. Intercom component; 201. Main control chip; 202. Wireless communication module; 203. Second connection module; 204. Power management module. DETAILED DESCRIPTION
[0040] The following embodiments of the present invention are described in further detail in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.
[0041] Embodiment 1: As shown in the attached Figure 1 As shown: The present invention provides a mobile phone-assisted intelligent intercom and an implementation method thereof, including a mobile phone end component 1 and an intercom end component 2;
[0042] The mobile phone component 1 includes a central processing unit 101, an audio processing chip 102, a first connection module 103, a speaker 104 and a microphone 105;
[0043] The intercom component 2 includes a main control chip 201, a wireless communication module 202, a second connection module 203 and a power management module 204; the wireless communication module 202 has a built-in radio frequency transceiver chip, and data is transmitted between the second connection module 203 and the first connection module 203, and the audio processing chip 102 uses a CNN noise reduction model to process digital audio signals.
[0044] The CNN denoising model is as follows:
[0045] The input noisy speech signal is x(n), and after short-time Fourier transform (STFT), the frequency domain representation X(k,f) is obtained, where k represents the time frame index and f represents the frequency index;
[0046] The CNN denoising model is represented by the function F CNN , the frequency domain signal after noise reduction is Y(k,f)=F CNN (X(k,f)); obtain the de-noised speech signal y(n) through inverse short-time Fourier transform (ISTFT);
[0047] For the first layer of the convolutional layer, the input feature map is A l-1 (k,f), the convolution kernel is W l , with a bias of b l , then the output feature map A l The calculation formula for (k,f) is:
[0048]
[0049] Where σ is the activation function, using the ReLU function; ReLU(x) = max(0,x); used to introduce nonlinear characteristics;
[0050] In the entire CNN model, through the combination of multiple such convolutional layers, pooling layers (used for downsampling to reduce the amount of data) and fully connected layers (used for classification or regression tasks), the mapping relationship from noisy speech features to denoised speech features is learned.
[0051] The specific steps of applying the CNN noise reduction model to perform noise reduction in the audio processing chip 102 are as follows:
[0052] Digital audio signals are framed and windowed;
[0053] Hamming window Where N is the window length, n = 0, 1, ..., N-1);
[0054] Then, a short-time Fourier transform (STFT) is performed to convert the audio signal into the frequency domain to obtain a time-frequency representation;
[0055] The time-frequency representation is used as the input of the CNN denoising model, and the denoised frequency domain signal is obtained after being processed by the model; the denoised frequency domain signal is then converted back to the time domain through the inverse short-time Fourier transform (ISTFT) to obtain the denoised digital audio signal, and then subsequent compression encoding and transmission operations are performed if necessary; this can effectively remove noise before the voice signal is transmitted, improve voice quality, reduce the amount of subsequent transmitted data because the noise component is reduced, and provide a clearer voice signal to the receiving end, thereby improving the performance of the entire intercom system.
[0056] The microphone 105 converts the input sound into an analog audio signal and transmits it to the audio processing chip 102; the audio processing chip 102 converts the analog audio signal into digital audio data, and performs noise reduction and gain adjustment; the main control chip 201 receives the digital audio data, unpacks and verifies it, and transmits it to the wireless communication module 202. The wireless communication module 202 has a built-in RF transceiver chip. The wireless communication module modulates the unpacked audio data into a RF signal and transmits it through the antenna to communicate with other walkie-talkies.
[0057] After receiving the audio data from other intercoms, the wireless communication module 202 demodulates the audio data into digital audio data and transmits it to the main control chip 201. The main control chip 201 adds verification and transmits the data to the second connection module 203; the second connection module 203 sends the audio data to the first connection module 103; the audio data is then transmitted to the audio processing chip 102 via the first connection module 103 and restored to an analog audio signal, which is played through the speaker 104.
[0058] The audio processing chip 102 uses the Opus algorithm to perform data compression; when the digital audio data received by the main control chip 201 is compressed data, it is restored to the original audio format through decoding and then transmitted to the wireless communication module 202.
[0059] The main control chip 201 sets the frequency and power of the radio frequency signal during the communication process to ensure the communication quality and distance.
[0060] The first connection module 103 and the second connection module 203 both use USB connection modules and also include a WI FI module and a Bluetooth module.
[0061] The mobile phone component 1 charges the walkie-talkie component 2 via a USB connection; the power management module 204 has a built-in step-down circuit and a filter circuit, and the power management module 204 monitors the charging status in real time; the step-down circuit uses a linear step-down regulator or a switching step-down converter to reduce the voltage to the appropriate voltage required by the walkie-talkie components, and uses a low-pass filter to filter out clutter and interference signals to make the power pure and stable; the power management module 204 monitors the charging status in real time, and detects the voltage, current size and battery charging level.
[0062] A method for implementing a mobile phone-assisted intelligent intercom, comprising:
[0063] S1. Preparation for audio processing and transmission on mobile phone:
[0064] The microphone 105 captures external sounds and converts them into analog audio signals and transmits them to the audio processing chip 102; after the audio processing chip 102 converts them into digital audio, it uses the CNN noise reduction model to remove noise and adjust the gain, and uses the Opus algorithm to compress the audio data, and finally sends the processed data to the first connection module 103;
[0065] S2. Data transmission from mobile phone to intercom:
[0066] The first connection module 103 sends the audio data to the second connection module 203 according to the selected connection mode WIFI, Bluetooth or USB according to the corresponding protocol. The second connection module 203 sends the data to the main control chip 201. The main control chip 201 unpacks and verifies the data after receiving it, decodes and restores the compressed data, and then transmits it to the wireless communication module 202.
[0067] S3. Intercom communication and data return:
[0068] The RF transceiver chip modulates the audio data into a RF signal and transmits it through the antenna to achieve communication with other walkie-talkies. The main control chip 201 will adjust the frequency and power of the RF signal to ensure communication. When receiving audio data from other walkie-talkies, the wireless communication module 202 demodulates and transmits it to the main control chip 201. The main control chip 201 adds verification and sends it back to the first connection module 103 on the mobile phone through the second connection module 203.
[0069] S4, mobile audio playback:
[0070] The first connection module 103 receives the data and sends it to the audio processing chip 102 . The audio processing chip 102 restores the digital audio data into an analog audio signal and plays it through the speaker 104 .
[0071] Example 2: At a large construction site, construction team members are distributed in different floors and areas. The project manager is equipped with the mobile phone-assisted intelligent intercom system of the present invention, where the mobile phone end is a common smart phone and the intercom end is a small and lightweight device.
[0072] Construction worker A uses an ordinary mobile phone to connect to the first connection module of the system on the noisy first floor through Bluetooth. When he speaks to the microphone 105 of the mobile phone, the sound is converted into an analog audio signal and transmitted to the audio processing chip 102. The audio processing chip 102 first converts it into digital audio data, and then uses the CNN noise reduction model to effectively remove various machine noises, human voices and other background noises at the construction site, and performs appropriate gain adjustment to make the voice clearer and more recognizable. Then the Opus algorithm is used to compress the audio data, and then the processed data is sent to the second connection module 203 at the intercom end near the construction site office through Bluetooth. The second connection module 203 transmits the data to the main control chip 201. After receiving, the main control chip 201 unpacks and verifies. Since the data is compressed, it is decoded and restored to the original audio format, and then transmitted to the wireless communication module 202. The RF transceiver chip of the wireless communication module 202 modulates the audio data into a RF signal and transmits it through the antenna.
[0073] At this time, the walkie-talkie held by construction worker B at the other end of the construction site receives the signal, and the wireless communication module 202 demodulates it into digital audio data and transmits it to the main control chip 201. The main control chip 201 adds verification and transmits the data to the second connection module 203. The second connection module 203 sends the audio data back to the first connection module 103 on the project manager's mobile phone through WI FI (because the office area has stable wireless network coverage). The first connection module 103 transmits the data to the audio processing chip 102. The audio processing chip 102 restores the digital audio data to an analog audio signal and plays it through the speaker 104 of the mobile phone, so that the project manager can clearly hear the report of construction worker A. Although the on-site environment is noisy, the CNN noise reduction model and stable communication process ensure smooth communication between the two parties.
[0074] The mobile audio processing chip 102 uses an advanced CNN noise reduction model to process digital audio signals, which can accurately identify and remove various complex background noises, such as the roar of machines at construction sites, the noise of crowds, and the wind and traffic noise in outdoor environments. After the noisy speech signal is represented in the frequency domain by short-time Fourier transform (STFT), it is input into the CNN model. After deep processing of multiple layers of convolution, pooling and fully connected layers, the precise mapping relationship from noisy speech features to noise-reduced speech features is learned, and then a clear speech signal is restored through inverse short-time Fourier transform (ISTFT). This process greatly improves the clarity and intelligibility of speech, ensuring that both parties can accurately convey information in a noisy environment, and effectively solves the problem of poor speech quality caused by noise interference in traditional cooperation methods.
[0075] In addition to removing noise, the audio processing chip 102 can also perform gain adjustment on the audio signal, so that the voice can maintain appropriate volume and sound quality in different environments and communication distances, further optimizing the audio effect, improving the user's auditory experience, and avoiding the situation where the communication effect is affected by uneven volume or too small or too large volume.
[0076] The audio processing chip 102 uses the Opus algorithm to compress the audio data, which can significantly reduce the amount of audio data while ensuring the audio quality. This is crucial for data transmission between the intercom and the mobile phone, especially when the bandwidth of wireless connections such as Bluetooth and WIFI is limited, effectively avoiding problems such as transmission delays, freezes, and even interruptions caused by excessive data volume. Through reasonable compression coding, audio data can be transmitted more quickly and stably between the mobile phone and the intercom, ensuring the real-time and smooth communication, and overcoming the problem of low audio data transmission efficiency in traditional cooperation.
[0077] When the main control chip 201 on the intercom side receives compressed digital audio data, it can accurately decode and restore it to the original audio format, and then transmit it to the wireless communication module 202 for transmission, thereby ensuring the integrity and accuracy of the audio data throughout the entire communication process, avoiding audio distortion or inability to play due to errors in the compression and decoding process, and realizing efficient adaptation and transmission of audio data between different devices and modules.
[0078] On the mobile phone side, the audio processing chip 102 can accurately convert the analog audio signal collected by the microphone 105 into digital audio data, and perform a series of processing and optimization to make it meet the requirements of intercom communication. At the same time, after the intercom receives the audio data of other intercoms, it can also be accurately converted into an audio format suitable for mobile phone playback through the main control chip 201 and related modules, and stably transmitted back to the mobile phone side, and transmitted to the audio processing chip 102 for playback through the first connection module 103, ensuring that the audio signal is not distorted or lost during the two-way conversion and matching process between the mobile phone and the intercom, solving the problem of audio signal conversion mismatch in the traditional matching method, resulting in reduced sound quality or failure to communicate normally.
[0079] The audio processing chip 102 on the mobile phone, the main control chip 201 on the intercom, and the CNN noise reduction work together to form a complete, efficient, and accurate audio communication chain from audio collection, processing, transmission to playback, which greatly improves the audio processing capability and adaptability of the intercom when used with a mobile phone, providing users with a clear, stable, and high-quality voice communication experience.
[0080] The embodiments of the present invention are provided for the purpose of illustration and description. Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations of the present invention. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present invention.
Claims
1. A mobile phone-assisted intelligent intercom, characterized in that: include: A mobile phone component (1), comprising a central processing unit (101), an audio processing chip (102), a first connection module (103), a speaker (104) and a microphone (105); A walkie-talkie end component (2) comprises a main control chip (201), a wireless communication module (202), a second connection module (203) and a power management module (204); the wireless communication module (202) has a built-in radio frequency transceiver chip, the second connection module (203) and the first connection module (203) perform data transmission, and the audio processing chip (102) uses a CNN noise reduction model to process digital audio signals.
2. A mobile phone-assisted intelligent intercom as claimed in claim 1, characterized in that: The CNN denoising model is as follows: The input noisy speech signal is x(n), and after short-time Fourier transform, the frequency domain representation X(k,f) is obtained, where k represents the time frame index and f represents the frequency index; The CNN denoising model is represented by the function F CNN , the frequency domain signal after noise reduction is Y(k,f)=F CNN (X(k,f)); obtain the de-noised speech signal y(n) through inverse short-time Fourier transform; For the first layer of the convolutional layer, the input feature map is A l-1 (k,f), the convolution kernel is W l , with a bias of b l , then the output feature map A l The calculation formula for (k,f) is: A l (k,f)=σ(∑ i,j W l (i,j)A l-1 (k-i,f-j)+b l ); Where σ is the activation function, using the ReLU function; The specific steps of applying the CNN noise reduction model to perform noise reduction in the audio processing chip (102) are as follows: Digital audio signals are framed and windowed; Using a Hamming window ( Where N is the window length, n = 0, 1, ..., N-1); Then a short-time Fourier transform is performed to convert the audio signal into the frequency domain to obtain a time-frequency representation; The time-frequency representation is used as the input of the CNN denoising model, and the denoised frequency domain signal is obtained after being processed by the model; the denoised frequency domain signal is then converted back to the time domain through the inverse short-time Fourier transform (ISTFT) to obtain the denoised digital audio signal, and then subsequent transmission operations are performed.
3. A mobile phone-assisted intelligent intercom as claimed in claim 1, characterized in that: The microphone (105) converts input sound into an analog audio signal and transmits it to the audio processing chip (102); the audio processing chip (102) converts the analog audio signal into digital audio data, and performs noise reduction and gain adjustment; the main control chip (201) receives the digital audio data, unpacks and verifies it, and transmits it to the wireless communication module (202); the wireless communication module (202) modulates the unpacked audio data into a radio frequency signal, and transmits it through an antenna to communicate with other intercoms.
4. A mobile phone-assisted intelligent intercom as claimed in claim 3, characterized in that: After receiving audio data from other intercoms, the wireless communication module (202) demodulates the audio data into digital audio data and transmits the data to the main control chip (201); the main control chip (201) adds verification and transmits the data to the second connection module (203); the second connection module (203) sends the audio data to the first connection module (103); the audio data is then transmitted to the audio processing chip (102) via the first connection module (103) and restored into an analog audio signal; the analog audio signal is played through the speaker (104).
5. A mobile phone-assisted intelligent intercom as claimed in claim 4, characterized in that: The audio processing chip (102) uses the Opus algorithm to perform data compression; when the digital audio data received by the main control chip (201) is compressed data, it is restored to the original audio format through decoding and then transmitted to the wireless communication module (202).
6. A mobile phone-assisted intelligent intercom as claimed in claim 5, characterized in that: The main control chip (201) sets the frequency and power of the radio frequency signal during the communication process to ensure the communication quality and distance.
7. A mobile phone-assisted intelligent intercom as claimed in claim 1, characterized in that: The first connection module (103) and the second connection module (203) are both USB connection modules.
8. A mobile phone-assisted intelligent intercom as claimed in claim 7, characterized in that: The mobile phone end component (1) charges the intercom end component (2) via a USB connection; the power management module (204) has a built-in step-down circuit and a filter circuit, and the power management module (204) monitors the charging status in real time.
9. A mobile phone-assisted intelligent intercom as claimed in claim 8, characterized in that: The first connection module (103) and the second connection module (203) further include a WIFI module and a Bluetooth module.
10. A method for implementing a mobile phone-assisted intelligent intercom, used in conjunction with any one of the mobile phone-assisted intelligent intercoms described in claims 1-9, characterized in that: include: S1. Preparation for mobile audio processing and transmission: The microphone (105) captures external sound and converts it into an analog audio signal and transmits it to the audio processing chip (102); after the audio processing chip (102) converts it into digital audio, it uses a CNN noise reduction model to remove noise and perform gain adjustment, uses the Opus algorithm to compress the audio data, and finally sends the processed data to the first connection module (103); S2. Data transmission from mobile phone to intercom: The first connection module (103) sends the data to the second connection module (203) according to the selected connection mode, and the second connection module (203) sends the data to the main control chip (201). After receiving the data, the main control chip (201) unpacks and verifies, decodes and restores the compressed data, and then transmits it to the wireless communication module (202); S3. Intercom communication and data return: The radio frequency transceiver chip modulates the audio data into a radio frequency signal and transmits it via an antenna to communicate with other intercoms, and the main control chip (201) regulates the frequency and power of the radio frequency signal to ensure communication; when receiving audio data from other intercoms, the wireless communication module (202) demodulates and transmits it to the main control chip (201), and the main control chip (201) adds verification and sends it back to the first connection module (103) on the mobile phone side via the second connection module (203); S4, mobile audio playback: The first connection module (103) receives the data and sends it to the audio processing chip (102). The audio processing chip (102) restores the digital audio data into an analog audio signal and plays it through the speaker (104).