KR100493806B1 - System For Rate Adaptor - Google Patents

Abstract

The present invention relates to a transmission rate conversion system. In particular, a transmission rate conversion system for converting a transmission rate suitable for each device between devices having different transmission rates in an IMT-2000 system is equipped with an echo cancellation function and a TFO function simultaneously. The present invention relates to a transmission rate conversion system for removing echoes generated during calls between mobile subscribers and improving voice quality.

The present invention includes: a matching unit for matching a switch module and a vocoder module having different transmission speeds; A transmission rate conversion unit for converting a transmission rate of a voice signal transmitted and received between the switch module and the vocoder module through the matching unit; It includes an echo canceller and a echo canceller for performing the TFO function on the voice signal received from the transmission rate converter, and does not use a CPU and an external memory to control the transmission rate converter. By simplifying the transmission rate conversion process, the time required to convert the transmission rate can be shortened, and the echo canceling unit is equipped with the echo canceling function to remove the echo sound felt by the telephone subscriber and the TFO function. You can improve the connection speed and voice quality when you make a conference call.

Description

Transmission Rate Conversion System {System For Rate Adapter}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission rate conversion system. In particular, a transmission rate conversion system for converting a transmission rate suitable for each device among devices having different transmission rates in an International Mobile Telecommunication-2000 (IMT-2000) system eliminates echoes The present invention relates to a transmission rate conversion system having both a function and a TFO function (Tandem Free Operation) at the same time to remove echoes generated during calls between mobile subscribers and to improve voice quality.

In general, when transmitting and receiving data between devices having different data rates in the IMT-2000 system, a data rate conversion system is required between the devices in order to convert different data rates to each device.

Hereinafter, a conventional rate conversion system will be described with reference to FIG. 1.

1 is a view showing a conventional transmission rate conversion system.

The conventional baud rate conversion system includes an echo cancellation unit 20, a relay line matching unit 10, a baud rate conversion unit 30, a storage unit 40, an address decoder 50, a CPU 60 and It consists of a transmission unit 70.

The echo removing unit 20 removes the echo generated during the voice call of the telephone subscriber, the relay line matching unit 10 matches with the public switched telephone network, and the transmission rate converting unit 30 converts the transmission rate. The data transfer rate is converted between the echo canceling unit 20 and the relay line matching unit 10 based on the code, and the storage unit 40 stores the transmission rate conversion code, and the address decoder 50 ) Decodes an address provided from the transmission rate converter 30, and the CPU 60 transmits from the storage 40 based on a decoding result of the address decoder 50. The rate conversion code is selectively extracted in 8-bit units, and the transmission unit 70 receives the 8-bit transfer rate conversion code extracted from the CPU 60 to transmit the rate conversion unit in 8-bit units. To 30).

Hereinafter, the operation of the conventional transmission rate conversion system configured as described above will be described.

The storage unit 40 is configured as a ROM to store a code for converting a transmission rate, and the address decoder 50 is configured to extract a code for changing a transmission rate stored in the storage unit 40. Decode the address provided from the transmission rate converter 30.

In addition, the CPU 60 selectively extracts a rate conversion code from the storage unit 40 in units of 8 bits based on the decoding result of the address decoder 50, and the transmission unit 40 The 8-bit buffer is used to receive the 8-bit transfer rate conversion code extracted from the CPU 60 and is provided to the transfer rate conversion unit 30 in units of 8 bits.

Accordingly, the transmission rate conversion unit 30 records the 8-bit transmission rate conversion code provided from the transmission unit 70 in a preset memory, and based on the transmission rate conversion code, the echo cancellation unit 20 ) And the data transmission rate between the relay line matching unit 10.

However, in the conventional rate conversion system, the code and data for the rate conversion are extracted under the control of the CPU, and the transfer rate conversion unit is controlled by the CPU by using the 8-bit buffer and transferred to the rate conversion unit. There was a problem that separate logic and memory were required.

In the IMT-2000 system, when a mobile telephone subscriber talks with each other, the voice signal of the mobile telephone subscriber is encoded and transmitted in accordance with the characteristics of the transmission system network by the transmitting mobile terminal. The mobile telephone terminal on the side decodes the encoded voice signal and delivers it to the receiver.

In the delivery process, a voice signal that is already encoded by a transmitting terminal is re-encoded and transmitted by a vocoder belonging to a mobile switching center (MSC) in an IMT-2000 system, and decoded by a vocoder on a receiving side to receive a terminal on a receiving side. As a result, the mobile phone terminal and the MSC are subjected to a process of encoding / decoding a voice signal twice each, which may cause a decrease in connection speed and quality of a voice call during a call between mobile subscribers.

In order to solve this problem, a vocoder in the MSC requires a series of processes that do not go through the process of recoding the voice signal coded in the mobile phone terminal. This process is performed by the TFO (Tandem Free Operation) function, that is, voice signal double coding. In the conventional transmission rate conversion system, the TFO function does not distinguish between the TFO data embedded in the voice signal because the TFO function is not provided in addition to the echo canceling function required by the IMT-2000 system. By processing the vocoder to not perform the TFO function, there was a problem in reducing the call connection speed and voice quality between the telephone subscribers.

In order to solve the problems described above, an object of the present invention is to use the CPU and the external memory for the control of the transmission rate conversion unit to simplify the configuration of the transmission rate conversion unit to simplify the transmission rate conversion process, This is to shorten the time required for the conversion.

In addition, another object of the present invention is to provide a echo canceling function to remove the echoes felt by the telephone subscriber and to provide a TFO function, thereby improving the connection speed and voice quality during the call between the telephone subscribers. .

A feature of the present invention for solving the above object is a transmission rate conversion system, comprising: a matching unit for matching a switch module and a vocoder module having different transmission rates; A transmission rate conversion unit for converting a transmission rate of a voice signal transmitted and received between the switch module and the vocoder module through the matching unit; And an echo canceller for performing echo cancellation and a TFO function on the voice signal received from the transmission rate converter.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

First, a mobile communication system to which the present invention is applied will be described with reference to FIG. 2.

2 is a diagram illustrating an IMT-2000 system to which the present invention is applied.

The IMT-2000 system to which the present invention is applied comprises a transmission system and a reception system. The transmission system includes a mobile switching center (MSC) 100 having a transmission rate conversion system 110 and a vocoder 120, an RNC ( Radio Network Controller (130), Node A (140), and a transmitting terminal (150), and the receiving system has a symmetrical structure with the transmitting system, the transmission rate conversion system 210 and the vocoder 220 The MSC 200, the RNC 230, the Node B 240, and the receiving terminal 250 are provided.

Here, the transmission speed conversion system (110,210) is connected to the sub-highway (SHW: Sub High Way), the transmission system between the transmission rate conversion system 110 and the vocoder 120 (THW: Traffic High Way) In the receiving system, a traffic highway is also connected between the transmission rate conversion system 210 and the vocoder 220.

Hereinafter, a transmission rate conversion system 110 according to an embodiment of the present invention will be described with reference to FIGS. 3, 4, and 5.

3 is a diagram illustrating a transmission rate conversion system according to an exemplary embodiment of the present invention, FIG. 4 is a diagram illustrating in detail a transmission rate converter in FIG. 3, and FIG. 5 is a diagram illustrating in detail an echo canceller in FIG. 3.

Hereinafter, although the transmission rate conversion system 110 belonging to the transmission system shown in FIG. 2 is demonstrated as an example, the following description applies similarly to the transmission rate conversion system 210 which belongs to a reception system.

Transmission rate conversion system 110 according to an embodiment of the present invention is a sub-highway matching unit 111, traffic highway matching unit 112, the rate conversion block (Rate Adaptation Block) 113, echo cancellation unit (Echo Canceller) 114), a central processor unit (CPU) unit 115, and an upper controller matching block (Controller Interface Block) 116.

The sub highway matching unit 111 matches an external receiving side MSC 200 through a sub high way (SHW), and the traffic highway matching unit 112 transmits an internal transmitting side vocoder 120 and a THW (Traffic). High speed), and the transmission rate conversion unit 113 converts a transmission speed between the sub highway matching unit 111 and the traffic highway matching unit 112, and the echo removing unit 114 converts the transmission speed. It removes the echo sound of the voice signal received from the rate converter 113 and supports the TFO function, that is, the voice signal double coding prevention function, and the CPU unit 115 communicates with the upper processor 117 and the echo agent. The reject control 114 is controlled, and the upper control matching unit 116 matches the upper processor 117 to control the upper processor 117.

Here, the transmission rate conversion unit 113 matches the echo cancellation unit 114 to set a voice signal path of a telephone subscriber and is composed of a field-programmable gate array (FPGA), and the sub-highway transmission rate module 113A is used. And a sub-way matching unit 111 having a data transmission rate of 4 Mbps (Mega Bit Per Second) having a traffic highway transmission rate module 113B and an internal memory 113c, and a traffic highway matching unit having a data transmission rate of 16 Mbps The transfer speed is converted between 112.

The sub-highway rate module 113A includes a sub-highway conversion block 113a, a sub-highway data transceiver 113d, a sub-highway data generator 113e, and a sub-highway address generator 113f. THW in which the SHW audio signal received from the sub highway matching unit 111 is stored in the internal memory 113c and then transmitted to the echo canceller 114 and the echo sound received from the echo canceller 114 is removed. After storing the voice signal in the internal memory 113c, the transmission speed is converted into the SHW voice signal and transmitted to the sub highway matching unit 111.

Here, the sub highway data transceiver 113d receives the received SHW voice signal from the sub highway matching unit 111 or transmits the transmitted SHW voice signal to the corresponding sub highway matching unit 111 and generates the sub highway address. The unit 113f generates an address for the transmitted / received SHW voice signal, and the sub highway data generator 113e extracts data for the received SHW voice signal and stores the received SHW voice signal data based on the address. Reads the received THW voice signal data stored in the internal memory 113c or the echo sound removed from the internal memory 113c, converts the transmission speed into the transmitted SHW voice signal, and transmits it to the sub highway data transmission / reception unit 113d. The sub highway conversion block 113a receives received SHW audio signal data stored in the internal memory 113c. Air brought and stored in the echo canceling (114) the transmit or echo canceling to 114 transmit the received reflections removed THW receiving the voice signal data inside a memory (113c) from.

The traffic highway transmission rate module 113B includes a traffic highway conversion block 113b, a traffic highway data transceiver 113g, a traffic highway data generator 113h, and a traffic highway address generator 113i. In this case, the THW voice signal received from the traffic highway matching unit 112 is stored in the internal memory 113c and then transmitted to the echo canceller 114 and the echo sound transmitted from the echo canceller 114 is removed. The stored SHW voice signal is stored in the internal memory 113c, and then the transmission speed is converted into the THW voice signal and transmitted to the corresponding traffic highway matching unit 112.

Here, the traffic highway data transceiver 113g receives the received THW voice signal from the traffic highway matcher 112 or transmits the transmitted THW voice signal to the corresponding traffic highway matcher 112 and generates the traffic highway address. The unit 113i generates an address for the transceived THW voice signal, and the traffic highway data generator 113h extracts data for the received THW voice signal and stores the received THW voice signal data based on the address. Reads the received SHW voice signal data stored in the internal memory 113c or the echo sound removed from the internal memory 113c, converts the transmission speed into the transmitted THW voice signal, and transmits the transmission speed to the traffic highway data transceiver 113g. The traffic highway conversion block 113b receives the received THW voice stored in the internal memory 113c. Call reads data transmitted to the echo canceling 114 or stores the transmitted reflections removed SHW received speech signal data received from the echo canceling (114) in the internal memory (113c).

The echo canceller 114 includes an echo canceller block 114a and a TFO data detection block 114b. The echo canceller 114a removes echoes of the voice signal and detects the TFO data. Block 114b detects TFO data in the voice signal and bypasses the corresponding TFO data.

Hereinafter, the operation of the transmission rate conversion system according to the embodiment of the present invention configured as described above will be described.

First, the operation of the sub-highway matching unit 111 will be described. The sub-highway matching unit 111 is a 4 Mbps (Mega Bit Per Second) that is transmitted from a telephone subscriber block through an external switch block, the MSC 200. Receives a PCM (Pulse Code Modulation) SHW voice signal having a transmission rate and transmits it to the sub-highway data transmission / reception unit 113d of the transmission rate conversion unit 113, and also the corresponding sub-highway data transmission / reception unit 113d. The voice signal is received and transmitted to the subscriber block through the MSC 200.

Hereinafter, the operation of the traffic highway matching unit 112 will be described. The traffic highway matching unit 112 is a decoded or encoded THW voice signal having a transmission rate of 16 Mbps transmitted from another vocoder 120. Receives and transmits to the traffic highway data transceiver 113g of the transmission rate converter 113, and receives the corresponding voice signal transmitted from the traffic highway data transceiver 113g to the vocoder 120. . Here, the sub highway matching unit 111 and the traffic highway matching unit 112 are configured with a driver / receiver suitable for SHW or THW matching.

Hereinafter, the operation of the transmission rate conversion unit 113, the transmission rate conversion unit 113 receives the SHW voice signal transmitted from the sub-highway matching unit 111 having a transmission rate of 4 Mbps of 16Mbps Sub-highway having a transmission rate of 4 Mbps by increasing the transmission speed to the traffic highway matching unit 112 having a transmission rate or receiving a THW voice signal transmitted from the traffic highway matching unit 112 of 16 Mbps The matching speed is reduced to the matching unit 111 and transmitted.

Also, the transmission rate converter 113 matches the echo canceller 114 so that the echo canceller 114 transmits the SHW voice signal data transmitted from the sub highway matcher 111 or the traffic highway. The voice signal data transmission / reception function is performed between the echo canceller 114 and the echo canceller 114 so as to perform the echo sound cancellation function on the THW audio signal data transmitted from the matching unit 112.

In addition, the transmission rate conversion unit 113 stores external transmission data necessary for mutually converting different transmission rates of voice signals transmitted and received by the sub highway matching unit 111 or the traffic highway matching unit 112. It is configured using an FPGA that does not require memory and buffers. Therefore, it is not controlled by a separate CPU for data rate conversion, and the FPGA does not require an external memory and a buffer for storing data by converting and transmitting data to be compatible with each other.

Hereinafter, more specifically, the transmission rate conversion unit 113, the transmission rate conversion unit 113 is a SHW voice signal transmitted from the sub-highway matching unit 111 or the traffic highway matching unit 112 or THW audio signals are transmitted or received based on the respective clock and frame sync signals.

Accordingly, the transmission rate conversion unit 113 counts the SHW or THW clocks for the sub highway matching unit 111 or the traffic highway matching unit 112 based on the respective frame synchronization signals in the FPGA to generate the SHW voice. Signal data or THW audio signal data is extracted, and the extracted SHW or THW audio signal data is stored in the internal memory 113c. Then, the transmission rate conversion unit 113 transmits the corresponding SHW or THW voice signal data to the echo canceller 114 and receives the SHW or THW audio signal data from which the echo is removed and transmits the received SHW or THW audio signal data to the corresponding internal memory 113c. After storing and reading the SHW or THW audio signal data from which the echo is removed, the transmission speed is converted into the SHW or THW audio signal in accordance with the clock and frame synchronization in the direction to be transmitted, and then the sub highway matching unit 111 or the traffic highway. By transmitting to the matching unit 112, the transmission rate is converted.

At this time, referring to the transmission rate conversion process from the sub-highway matching unit 111 with a low transmission rate to the traffic highway matching unit 112 with a high transmission rate, the sub-highway transmission rate module 113A of the transmission rate conversion unit 113 is described. ), The sub highway data transceiver 113d receives a serial SHW voice signal transmitted from the sub highway matching unit 111 in synchronization with the SHW clock and frame synchronization. In this case, the serial SHW voice signal bus repeats frames based on a frame synchronization signal indicating the start of each frame, and each SHW voice signal data is divided into a plurality of time slots within each frame.

Accordingly, the sub highway data generator 113e separately extracts the received SHW voice signal data for each time slot from the received SHW voice signal. Then, the sub highway address generator 113f counts the SHW clock based on the frame synchronization to generate an address corresponding to each time slot. Accordingly, the sub highway data generator 113e stores the extracted received SHW voice signal data in the internal memory 113c based on the address corresponding to each time slot.

The sub-highway conversion block 113a reads the received SHW audio signal data stored in the internal memory 113c and transmits the received SHW audio signal data to the echo canceller 114, and the echo canceller 114 performs the reception of the received SHW audio signal data. The echo is removed and then sent to the traffic highway transform block 113b. Accordingly, the traffic highway conversion block 113b stores the received SHW voice signal data from which the echo is removed in the internal memory 113c.

Accordingly, the traffic highway transmission rate module 113B reads the received SHW voice signal data from which the echo sound is removed from the internal memory 113c and loads the received SHW voice signal data on the THW voice signal bus. The traffic highway data generation unit 113h is performed. Receives the THW clock and frame synchronization required from the THW voice signal bus in order to transmit a transmit THW voice signal to traffic highway matching section 112.

The traffic highway address generator 113i counts a THW clock based on the THW frame synchronization to generate an address for the internal memory 113c in which the received SHW voice signal data is stored. 113h reads the received SHW audio signal data from the internal memory 113c based on the address and converts the transmission speed into a serial transmission THW audio signal.

Accordingly, the traffic highway data transceiver 113g transmits the transmitted THW voice signal to the traffic highway matching unit 112 in synchronization with the THW clock based on frame synchronization for each time slot of the THW voice signal bus. .

On the other hand, the transmission rate conversion process from the traffic highway matching unit 112 with a high transmission rate to the sub highway matching unit 111 with a low transmission rate is also described in the above-described sub-highway matching unit 111. Since it is the same as the transmission rate conversion process to the highway matching unit 112, a description thereof will be omitted.

The upper control matching unit 116 and the CPU unit 115 transmit and receive control signals for controlling the transmission rate conversion system 110 to perform operations corresponding to various controls required by the upper processor 117. In particular, the signal is received from the upper processor 117 to process various signals necessary to control the echo canceller 114 to perform the operation of the corresponding echo canceller 114 to be controlled by the upper processor 117. At this time, the upper control matching unit 116 is composed of a driver / receiver suitable for transmitting and receiving the upper control signal, the CPU 115 is composed of a CPU and a memory for storing the program of the CPU.

Hereinafter, referring to FIG. 5, the echo canceling unit 114 will be described. The echo canceling unit 114 removes the echo sound for the voice signal generated by the telephone subscriber when the telephone subscriber calls. By performing the operation of removing, matching with the transmission rate conversion unit 113 receives the voice signal data from the transmission rate conversion unit 113, removes the echo sound, and reverts the echo to the transmission rate conversion unit 113 again. Transmit voice signal data from which sound is removed.

In particular, the echo canceller 114 has a TFO function, i.e., a voice signal double coding prevention function, with an echo canceling function, and performs a echo canceling function during a call between telephone subscribers and provides a detection function for the TFO data. When the echo canceller 114 detects the TFO data received by the vocoder 120, the echo canceller 114 stops the echo cancellation function for the corresponding TFO data and transmits the TFO data transparently.

Accordingly, the echo canceller 114 detects the TFO data and guarantees the transparency of the TFO data, thereby allowing the vocoder to encode / encode the speech signal in duplicate for the speech signal encoded at the terminal of the subscriber. By not decoding, the vocoder reduces the coding time for the voice signal, thereby reducing the time required for setting the call path between the subscribers and the call quality improvement.

Hereinafter, more specifically, the echo canceller 114 will be described. The traffic highway baud rate module 113B receiving the transmission side voice signal data transmitted through the traffic highway matcher 112 from the vocoder 120 may be described. The transmission side audio signal data is transmitted to the echo cancellation unit 114, and the echo cancellation block 114a of the echo cancellation unit 114 stores the pattern of the transmitted transmission audio signal data.

In addition, the sub-highway rate module 113A, which has received the receiving-side voice signal data transmitted through the sub-highway matching unit 111 from the MSC 200, echoes the transmission rate of the corresponding receiving-side voice signal data 114. If the echo canceling block 114a of the echo canceling unit 114 detects a pattern similar to the transmitting speech signal in the transmitted receiving audio signal data, the echo canceling block 114a determines that the echo sound is to be a echo sound. After removing the component, the TFO data detection block 114b of the echo canceling unit 114 detects TFO data from the transmitted voice signal data and bypasses the echo without canceling the corresponding TFO data. The echo signal removed from the echo signal data and the bypassed TFO data are combined and then the traffic highway transmission rate module 113B and the traffic highway matching unit 11 are combined. 2) to the transmitting side vocoder 120.

In other words, the function that prevents the vocoder from recoding the voice signal coded in the mobile phone terminal is called a TFO function, that is, the voice signal double coding prevention function. TFO data detection function should be provided, and the vocoder in the MSC 200 embeds TFO data in the voice signal and transmits it to the echo cancellation unit 114 through the sub highway matching unit 111 and the sub highway transmission module 113A. In addition, the echo canceller 114 performs an echo canceller function only on the voice signal data except for the TFO data included in the transmitted voice signal, and bypasses the corresponding TFO data to cause the vocoder 120 to bypass. By allowing the TFO data to be received without distortion, the TFO function can be performed.

The echo cancellation block 114a removes the echo of the voice signal generated during the call between the mobile subscribers, and stores the transmission side voice signal pattern passing through the echo cancellation block 114a. When a voice signal pattern similar to the transmitter side included in the voice signal received through the receiver of the receiver is detected, it is determined to be a reverberation sound and the echo component can be removed by removing the echo component.

The echo canceller, which does not have a conventional TFO function, does not distinguish the TFO data inherent in the voice signal and treats the TFO data as a voice signal, thereby preventing the vocoder from performing the TFO function. The TFO data detection block 114b in the reject 114 functions to detect and bypass TFO data contained in the voice signal and transmit the TFO data, thereby enabling the vocoder to perform the TFO function.

In addition, the embodiment according to the present invention is not limited to the above-mentioned, and can be implemented by various alternatives, modifications, and changes within the scope apparent to those skilled in the art.

As described above, the present invention does not use the CPU and the external memory to control the transmission rate conversion unit, thereby simplifying the configuration of the transmission rate conversion unit, thereby simplifying the transmission rate conversion process, thereby reducing the time required for transmission rate conversion. In addition, the echo canceling unit includes a echo canceling function to remove echoes felt by the telephone subscribers and a TFO function, thereby improving connection speed and voice quality when the telephone subscribers call.

1 is a view showing a conventional transmission rate conversion system.

2 is a diagram illustrating an IMT-2000 system to which the present invention is applied.

3 is a view showing a transmission rate conversion system according to an embodiment of the present invention.

4 is a view showing in detail the transmission rate conversion unit in FIG.

FIG. 5 is a detailed view of an echo canceller in FIG. 3; FIG.

Explanation of symbols on main parts of the drawing

110: transmission rate conversion system 111: sub highway matching unit

112: traffic highway matching unit 113: transmission rate conversion unit

114: echo cancellation unit

Claims (6)

In the rate conversion system, A matching unit for matching a switch module and a vocoder module having different transmission rates with each other; A transmission rate conversion unit for converting a transmission rate of a voice signal transmitted and received between the switch module and the vocoder module through the matching unit; And an echo canceling unit performing echo canceling and a tandem free operation (TFO) function on the voice signal received from the transmission rate converting unit. The method of claim 1, The matching part, A sub-highway matching unit matching with the switch module through a sub high way (SHW); And a traffic highway matching unit matching through the vocoder module and a THW (Traffic High Way). The method according to claim 1 or 2, The transmission rate conversion unit, Sub to store the SHW voice signal in the internal memory and transmit it to the echo canceller, and store the THW audio signal from which the echo sound received from the echo canceller is removed in the internal memory and convert the transmission speed into the SHW audio signal. A highway transfer rate module; Storing a THW audio signal in the internal memory and transmitting the THW audio signal to the echo canceller, and storing the SHW audio signal from which the echo sound received from the echo canceller is removed in the internal memory and converting the transmission speed into a THW audio signal. A rate conversion system comprising a traffic highway rate module. The method of claim 3, wherein The sub highway speed module, A sub-highway data transceiver for receiving a received SHW voice signal from the sub-highway matcher or transmitting a transmitted SHW voice signal to a corresponding sub-highway matcher; A sub highway address generation unit generating an address for the transmission / reception SHW voice signal; Extracts data about the received SHW voice signal and stores the received SHW voice signal data in the internal memory based on the address, or reads the received THW voice signal data from which the echo sound is removed from the internal memory as the transmission SHW voice signal. A sub highway data generator for converting a transmission speed and transmitting the converted sub highway data to the sub highway data transceiver; And a sub-highway conversion block configured to read the received SHW audio signal data stored in the internal memory and transmit the received SHW audio signal data to the echo canceller or to store the echo-rejected received THW audio signal data received from the echo canceller in the internal memory. Transmission rate conversion system, characterized in that made. The method of claim 3, wherein The traffic highway transmission rate module, A traffic highway data transceiver for receiving a received THW voice signal from the traffic highway matcher or transmitting a THW voice signal to the traffic highway matcher; A traffic highway address generator for generating an address for the transceived THW voice signal; Extracts data about the received THW voice signal and stores the received THW voice signal data in the internal memory based on the address or reads the received SHW voice signal data from which the echo sound is removed from the internal memory as the transmission THW voice signal. A traffic highway data generator for converting a transmission speed and transmitting the converted traffic speed to the traffic highway data transceiver; And a traffic highway conversion block configured to read the received THW voice signal data stored in the internal memory and transmit the received THW voice signal data to the echo canceller or to store the echo sound-received received SHW audio signal data received from the echo canceller in the internal memory. Transmission rate conversion system, characterized in that made. The method of claim 1, The echo removing unit, An echo cancellation block for storing a voice signal data pattern of a transmitting side, detecting a similar pattern by comparing with the voice signal data pattern of the receiving side, and removing voice signal data of the similar pattern, thereby removing echo sound of the voice signal; And a TFO data detection block that detects TFO data in the voice signal and bypasses the TFO data.