WO2007118392A1

WO2007118392A1 - A method and device for transmitting voice data

Info

Publication number: WO2007118392A1
Application number: PCT/CN2007/000283
Authority: WO
Inventors: Shoubo Xie; Jie Yao; Tao Yu; Dong Zhang
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2006-04-17
Filing date: 2007-01-25
Publication date: 2007-10-25
Also published as: CN101317480A; CN100461906C; CN1984398A

Abstract

A method for transmitting voice data includes the steps of: identifying the inactivated voice data frame in voice data stream; according to the preset deletion strategy, deleting some or all of the identified inactivated voice data frames; after the deleting process, transmitting the voice data stream through the voice interface. In addition, a device for transmitting voice data is also disclosed. By means of the method of the invention, the amount of the inactivated voice data frame transmitted via voice interface could be reduced, and the capability of voice interface for bearing voice data could be improved, with almost no effect on the voice quality of the communication.

Description

Method and device for transmitting voice data

Technical field

The present invention relates to the field of mobile communication technologies, and in particular, to a method and apparatus for transmitting voice data. Background of the invention

A call is made between user terminals in a code division multiple access (CDMA) mobile communication system, and the voice of the call is encoded by a certain speech coding algorithm to obtain a voice data frame, and the obtained voice data frame passes the voice between the network devices. The interface is transmitted. A voice data frame includes a frame header and a voice payload. The frame header is frame format information defined for realizing transmission of a voice data frame in a physical layer. The voice payload is voice data formed by encoding a voice.

Different CDMA systems may use different speech coding algorithms. For example, the following three variable rate speech codec algorithms are mainly used in CDMA2000:

Enhanced Variable Rate Codec (EVRC), Qualcomm Code Excited Linear Prediction 13K (QCELP13K) and High-Through Code Excited Linear Predictive 8K Speech Angle Code coder ( Qualcomm Code Excited Linear Prediction 8K , QCELP8K ). The speech data frame length and air interface rate of different codecs at various rates are shown in Table 1: Algorithm 4^ rate Half rate 1/4 rate 1/8 rate

EVRC air interface rate ( bps ) 9600 4800 none 1200

20ms packet length (bit) 171 80 no 16 QCELP 8K air interface rate (bps) 9600 4800 2400 1600

20ms packet length ( bit ) 171 80 40 16

QCELP air interface rate (bps) 14400 7200 3600 1800 13K 20ms packet length (bit) 266 124 54 20 Table 1 Since the party is always talking, the other party is listening, and there is a gap in the voice, so the call can be made. The sound transmitted in is divided into two parts: effective speech and background noise. In the above encoding algorithm, the full rate speech payload is the encoding of the effective speech, and the half rate and 1/4 rate speech payload are the encoding of the effective speech and background noise transition bands, and the speech data frames of the above rates are It is called an active speech data frame; 1/8 frame is the encoding of background noise, also known as inactive speech data frame.

In the prior art, when a voice data frame is transmitted in a voice interface, the inactive voice data frame is transmitted along with the activated voice data frame. Since the inactive voice data frame does not actually transmit valid voice, the portion of the transmission bandwidth occupied by the inactive voice data frame is actually a waste of valuable bandwidth resources of the voice interface. Summary of the invention

The embodiment of the invention provides a method for transmitting voice data, which can improve the transmission efficiency of voice data.

The method comprises the following steps:

Identifying inactive voice data frames in the voice data stream;

Deleting some or all of the identified inactive voice data frames according to a preset deletion policy;

The deleted voice data stream is transmitted through the voice interface. The embodiment of the invention further provides an apparatus for transmitting voice data, which can improve the transmission efficiency of voice data.

The device includes the following modules:

a rate identifying unit, configured to receive a voice data frame and send the received voice data frame to a deletion processing unit; determine whether the received voice data frame is an inactive voice data frame, generate a deletion indication signal according to the result of the determination, and The generated deletion indication signal is sent to the deletion processing unit;

And a deletion processing unit, configured to save a preset deletion processing policy; perform a deletion operation on the currently received voice data frame according to the received deletion indication signal and the deletion processing policy, or output the received voice data frame.

The present invention also discloses a base station or a base station controller for transmitting voice data. The base station or the base station controller includes, in addition to the channel processing module and the interface processing module, a compression processing module for identifying the voice from the channel processing module. The inactive voice data frame in the data frame is deleted according to a preset policy, and some or all of the inactive voice data frames are deleted, and the deleted voice data frame is sent to the interface processing module.

It can be seen from the above technical solution that, at the transmitting end of the voice data frame, the inactive voice data frame is identified and deleted according to a certain policy, and the voice interface can transmit the inactive voice data under the condition that the voice quality of the call is hardly affected. The number of frames is reduced, improving the ability of the voice interface to carry voice data. BRIEF DESCRIPTION OF THE DRAWINGS

1 is a schematic structural view of a prior art CDMA system;

2 is a schematic diagram showing a frame structure of a voice data frame of an Abis interface;

3 is a schematic diagram of a system according to an embodiment of the present invention;

4 is a schematic diagram of an apparatus according to an embodiment of the present invention; FIG. 5 is a flowchart of processing according to an embodiment of the present invention. Mode for carrying out the invention

The embodiment of the invention includes the following basic contents:

At the transmitting end of the voice data frame, the transmitted voice data frame is identified, the inactive voice data frame is identified, some or all of the inactive voice data frames are deleted according to a certain policy, and the voice data frame is sent to The transmission channel of the voice interface. In order to ensure that the voice data stream composed of the voice data frames is continuous, the solution of the invention further comprises: detecting the silence in the received voice data stream at the receiving end of the voice data frame, and compensating the inactive voice data frame at the muted position.

In order to make the objects, technical solutions and advantages of the present invention more clear, the content of the present invention will be further described in detail below by taking a CDMA system as an example.

The structure of the CDMA system is shown in Figure 1. In the uplink direction, the signal sent by the terminal (MS) passes through the base transceiver station (BTS) and the base station controller (BSC)/packet control function node.

(PCF), connected to a Packet Data Serving Node (PDSN) or Packet Switching Center (MSC), which is then forwarded by the PDSN or MSC to the Internet (Internet), public land mobile network

(PLMN), Public Switched Telephone Network (PSTN) or Integrated Services Digital Network (ISDN); signals in the downstream direction are transmitted in the opposite direction to the above. For the entire CDMA system, it is desirable to increase the transmission bandwidth of the voice interface as much as possible, that is, the capacity of the interface to carry voice data. The voice interface includes an Abis interface between the BTS and the BSC and an A interface (including an A1 interface, an A2 interface, and an A5 interface) between the BTS and the MSC. Therefore, it is necessary to improve the transmission efficiency of the above interface as much as possible under the condition that the transmission equipment hardware of the Abis interface and the A interface are fixed.

The voice interface in this embodiment is an Abis interface between the BTS and the BSC. The protocol stack transmitted by the Abis interface is shown in Figure 2. The voice payload part of the voice data frame is encoded by some kind. The method for processing voice data, the encoding method may be one of the foregoing EVRC, QCELP13K or QCELP8K; the frame header portion includes an Abis frame header and a transmission bearer frame header, wherein the Abis frame header is used to ensure voice data in the BTS and the BSC The Abis interface is reliably transmitted, and the transmission bearer header is used to ensure reliable transmission of voice data in the physical channel.

Since the Abis interface of the CDMA system is not standardized, the content of the Abis frame header defined by each manufacturer is very different. Generally, the length of the Abis frame header is 4 to 8 bits; the transmission bearer header is also different according to the physical channel of the bearer, and there is an asynchronous transmission mode. (ATM), IP, Advanced Data Link Control (HDLC) or custom format, etc., typically 4 to 10 bits in length.

In order to improve the transmission efficiency of the interface, on the transmitting device of the voice data frame, the transmitted voice data frame is identified, the inactive voice data frame is identified, and some or all of the inactive voice data is deleted according to a certain policy. The frame is then sent to the transmission channel of the voice interface, so that the bandwidth of the voice interface can be saved.

The rate of each voice data frame can be determined by the physical layer rate determination, so as to determine whether the rate frame is an activated voice data frame or an inactive voice data frame; and the Abis frame header includes a frame number of the voice data frame, according to the frame number. Develop different inactive voice data frame processing strategies, such as deleting all inactive voice data frames, or deleting only inactive voice data frames with even frame numbers.

As shown in FIG. 3, the BTS and the BSC respectively access the Abis interface through the respective interface processing modules, and respectively add a compression processing module between the original channel processing module and the interface processing module of the BTS and the BSC, where

The compression processing module of the BTS device is configured to identify the inactive voice data frame in the service voice data frame, and delete some or all of the inactive voice data frames according to a preset policy; and also to identify the silence in the downlink voice data frame. A non-activated speech data frame is generated and filled in the identified mute position.

The compression processing module of the BSC device is used to analyze the Abis frame header in the downlink voice data frame. Feature information, identifying inactive voice data frames, and deleting some or all of the inactive voice data frames according to a pre-specified policy; also for identifying silence in the uplink voice data frame, generating inactive voice data frames and filling in the identified The mute position.

As can be seen from the above description, the functions of the compression processing module added in the BTS and the compression processing module added in the BSC are the same. Taking the BTS device as an example, the composition, connection relationship, and other modules of the internal unit of the compression processing module are the same. The connection relationship is as shown in FIG. 4: a rate identifying unit 401, configured to receive a voice data frame from a channel processing module of the BTS device, and perform physical layer rate determination on the voice data frame, if the rate of the voice data frame meets a non- Activating the determination condition of the speech data frame rate, generating an allow deletion indication signal, and transmitting the generated permission deletion indication signal and the speech data frame to the deletion processing unit 402, otherwise transmitting the speech data frame separately to the deletion processing unit 402. In this example, it is assumed that the encoding algorithm used is QCELP13K. The determination condition is that the rate of the voice data frame is 1/8 of the full rate, that is, the air interface rate is 1800 bps or the 20 ms packet length is 20 bits.

The deletion processing unit 402 is configured to save a preset deletion processing policy. When receiving the voice data frame from the rate identification unit 401, it is determined whether the permission deletion indication signal is received, and if received, determining whether to delete according to the deletion processing policy. If the voice data frame is deleted, the voice data frame is deleted, and a silence is formed in the time period occupied by the voice data frame; if the permission deletion instruction signal is not received or the voice data frame is not deleted according to the deletion processing policy, The received voice data frame is sent to the interface processing module.

The deletion processing policy may be: deleting all the identified inactive voice data frames; or determining whether the frame number of the identified inactive voice data frame satisfies certain conditions, such as whether it is an even number, and deleting the inactive condition that meets the condition. Voice data frame. The deletion processing policy is not limited to the above example, and may be set according to actual needs.

Through the above two units, it is possible to delete the inactive voice data frame when the voice interface sends a voice data frame. Before the process of deleting the inactive voice data frame, the voice data stream composed of the voice data frame is continuous without muting; after the deletion process, the silence is formed where the inactive voice data frame is deleted. In order to ensure that the voice data stream is continuous, the solution of the invention further comprises: at the receiving end of the voice data frame, detecting silence in the data stream composed of the received voice data frame, and compensating the inactive voice data frame in the muted position. The compression processing module also includes:

a silence time determining unit 403, configured to receive a voice data frame from the interface processing module and send the received voice data frame to the recovery unit 404; determine whether silence is present in the voice data frame, and if yes, to the recovery unit 404 sends a resume indication signal; the method of determining the silence is: setting a timer for performing silence time determination, the duration of the timer is the same as the voice data frame transmission interval of the Abis interface, for example, 20 milliseconds; When a voice data frame is reached, a reset operation is performed on the timer and the timing is restarted. If the timer expires, it indicates that no voice data frame is received between the current start timing of the timer and the timeout period, that is, a clock appears. The silence interval caused by the 1/8 frame being deleted.

The recovery unit 404 is configured to send the received voice data frame to the channel processing module. When the resume indication signal is received, a 1/8 frame is generated and sent to the channel processing module. The generating 1/8 frame is: generating 1/8 frame of the voice payload coded as FF, and the frame number is obtained by the mute position of the previous voice data frame number modulo 16 plus 1. Since the frame number is 0 to 15 cycles, if the frame number of the previous frame is 15, the frame number of the filled 1/8 frame is 0. The generated 1/8 frame voice payload code can also be a code for other comfort noise.

Referring to the description of the compression processing module of the BTS device, the composition and connection relationship of the compression processing module of the BSC device can be obtained, and therefore will not be described again.

The above compression processing device may be an independent device or integrated as a functional module in a base station or a base station controller in a base station or a base station controller. The processing flow of the uplink voice data frame by using the foregoing apparatus is as shown in FIG. 5, and includes the following steps:

Step 501: Determine a physical layer rate of the uplink voice data frame output by the BTS channel processing module, and identify an inactive voice data frame. In this embodiment, the inactive voice data frame is a 1/8 rate voice data frame.

Step 502: Delete some or all of the inactive voice data frames according to the pre-defined policy, and send the deleted uplink voice data stream to the transport channel of the Abis interface through the interface processing module of the BTS.

Step 503: The interface processing module of the BSC receives the uplink voice data stream of the Abis interface, and identifies the silence in the received data stream;

Step 504: Generate 1/8 frames and fill in the identified mute position, and then send the uplink voice data frame to the subsequent processing module of the BSC.

The processing flow of the downlink voice data frame can be obtained by referring to the above process, and therefore will not be described again. The speech effect processed by the embodiment of the present invention is evaluated by using the P.862 method, and the encoding algorithm of the speech data is EVRC. After processing in the embodiment of the present invention, the average opinion score (MOS) of the voice data is 3.739 points, and the score of the voice data after the prior art processing is 3.798 points. The processing of the present invention causes the MOS to drop by only 0.059 points, and it can be considered that the voice quality has not decreased. Therefore, the embodiment of the present invention reduces the waste of bandwidth resources of the Abis interface and greatly improves the voice bearer efficiency of the Abis interface under the premise that the call quality is not substantially affected. If the E1 interface is used in the Abis interface, the number of voice channels carried by each E1 interface can be increased from the normal 180 to 190 voice channels to more than 240 voice channels.

The solution of the present invention can also be applied to other voice interfaces in a CDMA system, for example, to an A interface between a BSC and an MSC, including interfaces such as Al, A2, and A5. The inventive solution can also be widely applied to other wireless communication systems, such as CDMA2000 systems. Those skilled in the art should recognize that as long as the variable rate speech data frame is continuously transmitted, The beneficial effects of improving the transmission efficiency are achieved by applying the solution of the present invention.

The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. Within the scope.

Claims

Claim

A method for transmitting voice data, the method comprising the steps of: identifying an inactive voice data frame in a voice data stream;

The deleted voice data stream is transmitted through the voice interface.

The method according to claim 1, wherein the identifying the inactive voice data frame in the voice data stream comprises: performing physical layer rate determination on the currently transmitted voice data frame, if the voice data The rate of the frame conforms to the decision condition of the inactive voice data frame, and the voice rate frame is the inactive voice data frame.

The method according to claim 2, wherein the rate of the voice data frame conforming to the inactive voice data frame is: the rate of the voice data frame is 1/8 rate.

The method according to claim 1, wherein the deleted part of the inactivated voice data frame is: determining whether the frame number of the inactive voice data frame satisfies a preset deletion condition, if Then delete the inactive voice data frame.

The method according to claim 1, wherein after the deleting the processed voice data stream by using the voice interface, the method further includes:

Receiving the deleted voice data stream, and identifying the silence in the received voice data stream;

A non-activated speech data frame is generated and populated at the identified muted position.

The method according to claim 5, wherein the setting of the duration of the voice data frame transmission interval, the identifying the silence in the voice data stream comprises:

When a voice data frame is received, the timer starts timing, if it is timed out If the next voice data frame is received before, the timer is reset and the step is continued; if the timer expires, the time between the timer starts to timeout and the timeout is muted.

The method according to claim 5, wherein the generating the inactive voice data frame is:

The generated voice payload code is FF, and the voice data frame number is the 1/8 rate frame of the previous voice data frame number modulo 16 plus 1.

The method according to any one of claims 1 to 6, wherein the voice interface is a voice interface between a base station and a base station controller, or a voice interface between the base station controller and the mobile switching center.

A device for transmitting voice data, the device comprising: a rate identifying unit, configured to receive a voice data frame and send the received voice data frame to a deletion processing unit; and determine whether the received voice data frame is Is a non-activated voice data frame, generating a deletion indication signal according to the result of the determination, and transmitting the generated deletion indication signal to the deletion processing unit;

The deletion processing unit is configured to save the preset deletion processing policy; the deletion indication signal and the deletion processing policy received by the residence delete the currently received voice data frame, or output the received voice data frame.

10. The apparatus according to claim 9, wherein the apparatus further comprises: a silence time determining unit, configured to receive a voice data frame and transmit the received voice data frame to a recovery unit; and determine the received voice Whether silence is present in the data frame, and if so, sending a recovery indication signal to the recovery unit;

And a recovery unit, configured to output the received voice data frame; when receiving the resume indication signal, generate an inactive voice data frame and output the inactive voice data frame.

11. A base station for transmitting voice data, comprising a channel processing module and an interface processing module, The base station further includes a compression processing module, configured to identify a non-activated voice data frame in a voice data frame from the channel processing module, and delete some or all of the inactive voice data frames according to a preset policy, and The deleted voice data frame is sent to the interface processing module.

The base station according to claim 11, wherein the compression processing module comprises:

a rate identifying unit, configured to receive a voice data frame from the channel processing module and send the received voice data frame to the deletion processing unit; determine whether the received voice data frame is an inactive voice data frame, and generate a deletion indication according to the determined result Signaling, and transmitting the generated deletion indication signal to the deletion processing unit;

a deletion processing unit, configured to save a preset deletion processing policy; perform a deletion operation on the currently received voice data frame according to the received deletion indication signal and the deletion processing policy; or send the received voice data frame to the interface processing module.

The base station according to claim 12, wherein the compression processing module further comprises:

a silence time determining unit, configured to receive a voice data frame from the interface processing module and send the received voice data frame to the recovery unit; and determine whether silence is present in the received voice data frame, and if yes, send and recover to the recovery unit Indication signal

And a recovery unit, configured to send the received voice data frame to the channel processing module; when the recovery indication signal is received, generate an inactive voice data frame and send the inactive voice data frame to the channel processing module.

A base station controller for transmitting voice data, comprising a channel processing module and an interface processing module, wherein the base station further comprises a compression processing module, configured to identify inactive voice in a voice data frame from the channel processing module Data frame, and delete some or all of the inactive voice data frames according to a preset policy, and delete the processed voice data frames Send to the interface processing module.

The base station controller according to claim 14, wherein the compression processing module comprises:

a rate identifying unit, configured to receive a voice data frame from the channel processing module and send the received voice data frame to a deletion processing unit; determine whether the received voice data frame is an inactive voice data frame, and generate a result according to the judgment result Deleting the indication signal, and transmitting the generated deletion indication signal to the deletion processing unit;

The base station controller according to claim 15, wherein the compression processing module further comprises: