WO2013155777A1

WO2013155777A1 - Wireless conference terminal and voice signal transmission method therefor

Info

Publication number: WO2013155777A1
Application number: PCT/CN2012/076926
Authority: WO
Inventors: 张健; 王钢
Original assignee: 中兴通讯股份有限公司
Priority date: 2012-04-17
Filing date: 2012-06-14
Publication date: 2013-10-24
Also published as: CN103379231A; CN103379231B

Abstract

A wireless conference terminal and a voice signal transmission method therefor. The terminal comprises a wireless module, a DSP voice processing module, a voice receiving module and a voice output module, wherein the wireless module is connected to the DSP voice processing module through an I2S or PCM interface; the wireless module is used for achieving wireless access to the wireless conference terminal, sending a received downlink voice signal to the DSP voice processing module, and sending a received uplink voice signal to a wireless network; the voice receiving module is used for acquiring a sound in an environment, and sending the acquired uplink voice signal to the DSP voice processing module; the DSP voice processing module is used for conducting voice enhancement on the received uplink voice signal, and then sending same to the wireless module, and is also used for conducting noise reduction on the received downlink voice signal, and then sending same to the voice output module; and the voice output module is used for outputting the received downlink voice signal.

Description

Wireless conference terminal and method for transmitting voice signal thereof

Technical field

The present invention relates to a conference telephone system, and in particular to a wireless conference terminal and a method for performing voice signal transmission. Background technique

Conference telephones, as a market segment application of telephones, have existed and are widely used in enterprises and institutions. At present, the conference telephone products of traditional manufacturers are wired in the form of PSTN (Public Switched Telephone Network) and IP. Access is dominant. With the strong momentum of mobile communication, the market for fixed networks has been greatly squeezed, and conference calls with wireless access capabilities are bound to become the future development trend. Currently, wireless conference phones on the market basically use the following two methods:

1) using DECT (Digital Enhanced Cordless Telecommunications) technology, the conference call is made into a DECT slave, and connected to the PSTN network through the DECT module;

2) Connect to the mobile phone through a cable or Bluetooth to connect to the mobile network.

However, neither of these methods uses wireless modules (such as GSM (Global System for Mobile communications), CDMA (Code Division Multiple Access), WCDMA (Wideband Code Division Multiple Access). Multiple access), etc.) Connect directly to the mobile network.

However, if a mobile terminal with a wireless module (such as a mobile phone) is directly used as a conference terminal, the hands-free function of the terminal is inevitably used, but the hands-free function on the existing mobile terminal cannot guarantee the sound quality. In order to meet the demand of the mobile phone for the conference call, the voice cancellation processing can be used for some mobile terminals to meet the demand for the large volume of the conference call. For example, the invention of the application number CN200820126629.0 discloses a conference telephone terminal. However, the invention only involves echo suppression, and it is difficult to meet the high sound quality requirements of the conference call. Summary of the invention

An object of the embodiments of the present invention is to provide a wireless conference terminal and a method for performing voice signal transmission thereof, so as to overcome the defect that the existing mobile terminal cannot meet the high sound quality requirement of the conference call.

To solve the above problem, an embodiment of the present invention provides a wireless conference terminal, including: a wireless module, a digital signal processing (DSP) voice processing module, a voice receiving module, and a voice output module; wherein, the wireless module and the DSP The voice processing module is connected through a stereo frequency serial interface controller (I2S) or a pulse code modulation (PCM) interface;

The wireless module is configured to implement wireless access of the wireless conference terminal, and send the received downlink voice signal to the DSP voice processing module, and send the received uplink voice signal to the wireless network;

The voice receiving module is configured to collect sounds in the environment, and then send the collected voice signals to the DSP voice processing module;

The DSP voice processing module is configured to perform voice enhancement processing on the received uplink voice signal, and send the processed uplink voice signal to the wireless module; and is further configured to perform noise reduction processing on the received downlink voice signal. Sended to the voice output module;

The voice output module is configured to output the received downlink voice signal.

Optional,

The voice receiving module includes a multi-channel microphone;

The DSP voice processing module is configured to perform voice enhancement processing on the received uplink voice signal, and specifically includes:

The DSP processor performs ambient noise suppression on the uplink voice signal collected by the multi-channel microphone as an ambient noise signal other than the strongest signal.

Optional,

The DSP voice processing module is configured to use the received downlink voice signal as an echo suppression The reference signal is then estimated according to the size of the downlink voice signal, and the echo signal included in the uplink voice signal received by the module is estimated, and the estimated echo signal is subtracted from the uplink voice signal to implement echo suppression.

Optional,

The DSP voice processing module is further configured to perform automatic gain adjustment on the received uplink voice signal.

Optional,

The DSP voice processing module includes: a DSP processor and a codec ( CODEC ) connected through an I2S interface or a PCM interface;

The CODEC is configured to perform the coded uplink voice signal sent by the voice receiving module and send the code to the DSP processor;

The DSP processor is configured to perform voice enhancement processing on the received uplink voice signal and then send the signal to the wireless module. The DSP processor is further configured to perform noise reduction processing on the received downlink voice signal and send the signal to the CODEC.

Optional,

The CODEC is further configured to perform automatic gain adjustment on the received uplink voice signal and/or downlink voice signal, and output after the adjustment is completed.

Correspondingly, the embodiment of the present invention further provides a method for transmitting a voice signal by a wireless conference terminal, which is applied to a wireless conference terminal including: a wireless module, a digital signal processing (DSP) voice processing module, a voice receiving module, and a voice output module. The wireless module is connected to the DSP voice processing module through a stereo frequency serial interface controller (I2S) or a pulse code modulation (PCM) interface;

For an uplink voice signal, the method includes:

The voice receiving module collects the sounds in the environment, and then collects the uplink voice signals Sending to the DSP voice processing module;

The DSP voice processing module performs voice enhancement processing on the received uplink voice signal, and sends the processed uplink voice signal to the wireless module;

The wireless module implements wireless access of the wireless conference terminal, and sends the received uplink voice signal to the wireless network;

For a downlink voice signal, the method includes:

The wireless module sends the received downlink voice signal to the DSP voice processing module; the DSP voice processing module performs noise reduction processing on the received downlink voice signal, and then sends the downlink voice signal to the voice output module;

The voice output module outputs the received downlink voice signal.

Optional,

The voice receiving module includes a multi-channel microphone;

The DSP voice processing module performs voice enhancement processing on the received uplink voice signal, which specifically includes:

Optional,

The step of the DSP voice processing module performing voice enhancement processing on the received uplink voice signal includes:

The DSP voice processing module uses the received downlink voice signal as an echo suppression reference signal, and then estimates an echo signal included in an uplink voice signal received by the module according to the size of the downlink voice signal, and uses the uplink. The estimated echo signal is subtracted from the speech signal to achieve echo suppression.

Optional,

The step of the DSP voice processing module performing voice enhancement processing on the received uplink voice signal includes: The DSP voice processing module performs automatic gain adjustment on the received uplink voice signal.

The wireless conference terminal of the embodiment of the present invention has the following advantages compared with the current mobile phone type wireless terminal products:

The multi-channel MIC can sequentially collect the voice into the DSP voice processing module, and the DSP voice processing module selects the main MIC according to the strength of the signal collected by the MIC, and the other is used as the auxiliary MIC, and the voice collected by the auxiliary MIC is used as the background noise reference. Remove background noise;

Multi-channel MIC can collect voices in all directions and achieve 360-degree pickup;

高Using high-sensitivity MIC and AGC function in DSP speech processing module can achieve long-distance pickup, ensuring consistent sound size within a certain range, and sound smooth and natural;

Upward volume input, down volume output. With automatic echo suppression, no echo interference, to meet the needs of conference calls.

Compared with the PSTN fixed network and the IP conference call, the wireless conference terminal of the embodiment of the present invention uses the mobile wireless network for wireless access, and the wireless access mode and the battery power supply form are more suitable for the frequently changing venue.

BRIEF abstract

1 is a structural diagram of a wireless conference terminal according to an embodiment of the present invention;

3 is a schematic diagram of connection between a wireless module and a DSP voice processing module according to an embodiment of the present invention; FIG. 4 is a flow chart showing specific communication control of a wireless module and a DSP voice processing module according to an embodiment of the present invention. Preferred embodiment of the invention

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that, in the case of no conflict, the features in the embodiments and the embodiments in the present application may be arbitrarily combined with each other.

Because the conference terminal has high requirements on sound quality, including down-high volume output, long-distance pickup, Noise suppression, echo suppression, etc. can not be completed using the current mobile terminal hands-free solution.

In this embodiment, the wireless conference terminal uses a DSP (Digital Signal Processing) voice processing module for voice processing, and the DSP voice processing module includes a DSP processor and a CODEC (codec), CODEC. It is used to complete the sampling and encoding and decoding of voice signals. The DSP processor is used for voice noise suppression, echo suppression, AGC (Automatic Gain Control) voice enhancement and other speech processing for the collected voice signals.

As shown in Figure 1, the wireless conference terminal includes the following modules:

Wireless module: The wireless module uses the current baseband processing scheme of the mobile phone to complete the wireless access of the conference terminal and the transmission of the uplink and downlink voice signals. For the received downlink voice signal, the I2S (Inter-Integrated-Circuit Sound Controller) Line interface controller) or PCM (Pulse Code Modulation) interface is sent to the DSP voice processing module; Voice receiving module: used to complete the collection of uplink voice, and send the collected uplink voice signal to DSP voice The processing module performs voice enhancement processing; in a specific implementation, the multi-channel MIC can be used to implement the function of the voice receiving module. Preferably, the multi-channel MIC can be uniformly set in the wireless conference terminal to achieve 360-degree sound collection;

The DSP voice processing module performs voice enhancement processing on the uplink voice signal collected by the voice receiving module, and sends the processed uplink voice signal to the wireless module through the I2S or PCM interface; and can also receive the downlink voice received by the wireless module. The signal is processed and the processed downstream speech signal is sent to the speech output module.

Specifically, the DSP voice processing module performs voice enhancement processing on the uplink voice signal, including:

(1) Environmental noise suppression

The CODEC in the DSP voice processing module is used for separately encoding the voice signals collected by the multi-channel MIC, and transmitting the encoded voice signals to the DSP processor in the DSP voice processing module through the I2S or PCM interface; The DSP processor is configured to judge the intensity of the received multi-channel speech signal, and use the signal with the strongest intensity as the speech signal, and use other road speech signals except the strongest speech signal as the ambient noise, and then The environmental noise is suppressed. For the specific environmental noise suppression method, refer to the prior art, and no further comments are made here;

(2) echo suppression Since the conference terminal needs to use a large volume output, echo suppression is critical. The wireless module sends the received downlink voice signal to the DSP processor through the I2S or PCM interface; the DSP processor uses the received downlink voice signal as an echo suppression reference signal, and then estimates the DSP voice according to the size of the downlink voice signal. The echo signal included in the uplink voice signal collected by the receiving module is used to subtract the estimated echo signal from the uplink voice signal to implement echo suppression. The specific process of the echo suppression may refer to the prior art.

(3) long-distance pickup

The DSP processor can configure the AGC related register in the CODEC, and the CODEC automatically performs gain adjustment on the received uplink voice signal according to the configuration, and automatically reduces the excessive signal (that is, the signal whose intensity exceeds the preset upper limit of the sound intensity). Gain, increase the gain for small signals (that is, signals whose intensity is lower than the preset lower limit of sound intensity), so that the sound size is basically the same within a certain range, which satisfies the requirement of long-distance pickup of the conference terminal. If the CODEC AGC performance cannot meet the requirements, it can be adjusted twice by the DSP processor, and the DSP processor can automatically adjust the gain of the received voice signal again.

Specifically, the DSP voice processing module processes the downlink voice signal, including:

The DSP processor in the DSP voice processing module is configured to perform noise reduction processing on the downlink voice signal, and then send the signal to the CODEC through the I2S or PCM interface; the CODEC can configure a DRC (Dynamic Range Compression) related register to receive the The downlink speech signal is automatically adjusted, that is, the gain is increased for the small signal, and the gain is reduced for the large signal, so that the sound is smooth.

In addition, an audio amplifier can also be set in the wireless conference terminal, and the CODEC sends the processed downlink voice signal to the audio amplifier, and the audio amplifier amplifies the downlink voice signal and outputs the voice signal to the voice output module to meet the large volume of the conference terminal. demand.

As shown in FIG. 2, in this embodiment, a method for performing voice signal transmission by using a wireless conference terminal includes the following steps:

Step A: Multi-channel MIC for voice and environmental noise collection;

Step B: The MIC sends the collected voice and environmental noise signals to the DSP voice processing module. Complete environmental noise suppression and TDD noise suppression;

Step C: The wireless module enters the received downlink voice into the DSP voice processing module for noise reduction processing, and at the same time serves as a reference signal for echo suppression, and adaptively suppresses the echo according to the strength of the downlink voice signal;

Step D: For the up-going voice signal after noise reduction and echo cancellation, the automatic gain adjustment is performed according to the intensity, so that the sound size within a certain distance is consistent, smooth and natural, and meets the long-distance pickup of the conference terminal;

Step E: After performing ambient noise suppression, echo suppression, and AGC processing on the uplink voice signal, the DSP voice processing is sent to the wireless module through the I2S or PCM interface, and the wireless module completes the uplink voice transmission;

Step F: The DSP voice processing module outputs the processed downlink voice signal to the voice output module for output.

Figure 3 is a simplified diagram of the connection between the wireless module and the DSP voice processing module via the I2S or PCM interface:

The wireless module transmits voice signals through the I2S or PCM interface. Usually, the DSP voice processing module and the wireless module are in a sleep state. The wireless module's GPIOA is connected to the interrupt pin of the DSP voice processing module. When the wireless module is woken up, the GPIOA on the wireless module is set to a high level to cause the DSP voice processing module to generate an interrupt to wake up the DSP voice processing module; when the wireless module enters the sleep state, the wireless module sets the GPIOA to a low level. The DSP voice processing module is notified to go to sleep. In addition, the wireless module will notify the current call status through the GPIOB status, and the GPIOB is high when the call is made. When the DSP voice processing module detects that the wireless module's GPIOB is high, the CODEC is started to perform the uplink voice signal. The specific process is shown in Figure 4, including: Step 1: The wireless module is woken up, setting GPIOA to high level;

Step 2: When it is detected that GPIOA is high, the DSP voice processing module generates an interrupt to wake up the DSP voice processing module;

Step 3: The DSP voice processing module detects the GPIOB state. When the GPIOB state is high, indicating that the current state is the call state, step 5 is performed, otherwise step 4 is performed;

Step 4: Stop the CODEC voice sample, and the DSP voice processing module stops the uplink voice signal. Processing, only downlink voice processing, perform step 6;

Step 5: Start the CODEC voice sample, and the DSP voice processing module processes the uplink voice signal, and transmits the processed uplink voice signal to the wireless module through the I2S or PCM interface. Step 6: The wireless module passes the received downlink voice signal. The I2S or PCM interface is sent to the DSP voice processing module for noise reduction and output, and step 7 is performed;

Step 7: After the wireless module enters hibernation, set GPIO A to low level. The DSP voice processing module detects that the wireless module's GPIOA is low and then goes to sleep to stop the transmission of voice signals.

One of ordinary skill in the art will appreciate that all or a portion of the above steps may be accomplished by a program instructing the associated hardware, such as a read-only memory, a magnetic disk, or an optical disk. Alternatively, all or part of the steps of the above embodiments may also be implemented using one or more integrated circuits. Correspondingly, each module/unit in the above embodiment may be implemented in the form of hardware or in the form of a software function module. The invention is not limited to any specific form of combination of hardware and software.

The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. In view of the present invention, various other modifications, equivalents, improvements, etc., should be made without departing from the spirit and scope of the invention. It is included in the scope of protection of the present invention.

Industrial applicability

Compared with the PSTN fixed network and the IP conference call, the wireless conference terminal in the embodiment of the present invention uses the mobile wireless network for wireless access, and the wireless access method and the battery power supply are more suitable for the frequently changing venue.

Claims

Claim

1. A wireless conference terminal, comprising:

a wireless module, a digital signal processing (DSP) voice processing module, a voice receiving module, and a voice output module;

The wireless module is connected to the DSP voice processing module through a stereo frequency serial interface controller (I2S) or a pulse code modulation (PCM) interface;

The wireless module is configured to: connect the wireless conference terminal to a wireless network, and send the received downlink voice signal to the DSP voice processing module, and send the received uplink voice signal to the wireless network;

The voice receiving module is configured to: collect sounds in the environment, and then send the collected uplink voice signals to the DSP voice processing module;

The DSP voice processing module is configured to: perform voice enhancement processing on the received uplink voice signal, and then send the signal to the wireless module; and perform the noise reduction processing on the received downlink voice signal, and send the received voice signal to the voice output module;

The voice output module is configured to: output the received downlink voice signal.

2. The wireless conference terminal of claim 1 wherein:

The voice receiving module includes a multi-channel microphone;

The DSP voice processing module is configured to perform voice enhancement processing on the received uplink voice signal in the following manner:

In the multi-channel uplink speech signal collected by the multi-channel microphone, the uplink speech signal except the highest-intensity uplink speech signal is used as an environmental noise signal to perform environmental noise suppression.

3. The wireless conference terminal of claim 1, wherein:

According to the strength of the received downlink voice signal, the echo signal included in the uplink voice signal received by the module is estimated, and the estimated echo signal is subtracted from the uplink voice signal to implement echo suppression.

4. The wireless conference terminal of claim 1, wherein:

Automatic gain adjustment is performed on the received uplink voice signal.

The wireless conference terminal according to any one of claims 1 to 4, wherein:

The CODEC is configured to perform the coded encoding on the uplink voice signal sent by the voice receiving module, and send the code to the DSP processor;

The DSP processor is configured to: perform voice enhancement processing on the received uplink voice signal, and then send the signal to the wireless module; and perform the noise reduction processing on the received downlink voice signal, and then send the downlink voice signal to the CODEC.

6. The wireless conference terminal of claim 5, wherein:

A method for transmitting a voice signal by a wireless conference terminal, which is applied to a wireless conference terminal including a wireless module, a digital signal processing (DSP) voice processing module, a voice receiving module, and a voice output module, wherein the wireless module and the wireless module The DSP voice processing module is connected by a stereo frequency serial interface controller (I2S) or a pulse code modulation (PCM) interface; the method includes:

For uplink voice signals,

The voice receiving module collects the sounds in the environment, and then sends the collected uplink voice signals to the DSP voice processing module;

The DSP voice processing module performs voice enhancement processing on the received uplink voice signal, and then sends the uplink voice signal to the wireless module;

The wireless module accesses the wireless conference terminal to a wireless network, and transmits the received uplink voice signal to the wireless network;

For the downlink voice signal, the wireless module sends the received downlink voice signal to the DSP voice processing module;

The DSP voice processing module performs noise reduction processing on the received downlink voice signal, and then sends the downlink voice signal to the voice output module.

The voice output module outputs the received downlink voice signal.

8. The method of claim 7 wherein:

The voice receiving module includes a multi-channel microphone;

The DSP processor performs ambient noise suppression on the uplink voice signal other than the strongest uplink voice signal as the ambient noise signal in the multiple uplink voice signals collected by the multiple microphones.

9. The method of claim 7 wherein:

The DSP voice processing module estimates an echo signal included in the uplink voice signal received by the module according to the strength of the received downlink voice signal, and uses the uplink voice signal to subtract the estimated echo signal to implement the echo. inhibition.

10. The method of claim 7 wherein:

The DSP voice processing module performs automatic gain adjustment on the received uplink voice signal.