KR100407938B1 - Apparatus for processing voice of mobile telecommunication system - Google Patents

Abstract

The present invention relates to a voice processing apparatus of a mobile telephone system capable of resolving delays of a predetermined level or more, comprising: a first voice processing unit for removing echoes caused by delays below a predetermined level, and an echo generated by delays of a predetermined level or more. A second voice processing unit and a switching unit for selecting the first voice processing unit or the second voice processing unit according to a user's request, and a delay at which a conventional DSP vocoder can remove echoes is a predetermined level (24 ms). It is possible to remove echoes caused by more delays according to the user's request, so that the sound quality can be improved while improving the reliability of the product.

Description

Apparatus for processing voice of mobile telecommunication system

The present invention relates to a mobile telephone system, and more particularly, to a voice processing apparatus of a mobile telephone system.

In general, the voice signal processing in the mobile phone system is very different from the voice signal processing method in the digital wired telephone system. PCM 64Kbps or ADPCM 32Kbps data, which is a well-known digital voice coding method, can be transmitted in a wireless section. Only a voice signal digitized with a coding method of 9.6 Kbps or less can be transmitted in real time in a wireless section.

Such low-speed voice signal coding is impossible to implement with a wave-type coding method for sampling and decoding voice waveforms, and is a voice coding method for modeling a voice signal and extracting parameters of a signal model. Use

Since the vocoding method of the audio signal is a concept of collecting a voice signal per unit frame and extracting and transmitting the voice characteristic and the residual signal information of the frame, the signal processing time is always between the time of the input signal and the information time of the output signal. Because delay occurs, echo signals are not felt in analog systems, so echo cancellers are essential.

The echo generated by the mobile telephone system can be classified into acoustic echo generated between the speaker and the microphone of the mobile terminal and line echo generated from the hybrid circuit of the wired subscriber line connection. It is determined by the time delay and time delay, and the time delay acts more than the size of the echo.

Hereinafter, a voice processing apparatus of a mobile telephone system according to the related art will be described in more detail with reference to the accompanying drawings.

1 is a view showing a voice processing apparatus of a mobile telephone system according to the prior art.

As shown in FIG. 1, the voice processing apparatus of the mobile telephone system according to the prior art includes a CPU 1 which outputs a control signal and a first buffer 2 to which an address bus line output from the CPU 1 is input. ), A second buffer 3 to which the data busline output from the CPU 1 is input, and a third output through the PIO port so that voice data packets output from the CPU 1 are made in units of bytes. A buffer 4, a DSP vocoder 5 for restoring the original speech data from the speech data output from the third buffer 4, and outputs of the first buffer 2 and the second buffer 3 A memory 7 for sharing and storing, and a switch 6 operative to transmit PCM data to the DSP vocoder 5 in synchronization.

In addition, a reset signal applied to the DSP vocoder 5 is controlled by the CPU 1, and a 50 Hz clock applied to the DSP vocoder 5 provides an interrupt in units of CDMA frames so that the DSP vocoder synchronizes with it. To match. At this time, the command and voice data packet between the CPU 1 and the DSP vocoder 5 are made in units of bytes through the parallel port, and the PCM voice signal with the wired network is made through the serial port.

Therefore, the PCM highway can be connected without external logic, and the echo canceller existing in the DSP vocoder 5 modifies the coefficients of the internal filter with the information of the data output from the DSP vocoder 5 and then inputs the data. Compare and remove the same signal or echo as the output data component.

As described above, the voice processing apparatus of the conventional mobile phone system has the following problems.

First, because the filter coefficients are fixed in the process of removing echoes, the echoes are not eliminated when an acoustic echo and a delay are generated.

Second, echoes are not eliminated because the environment of export is different.

Disclosure of Invention The present invention has been made to solve such a problem, and an object thereof is to provide a speech processing apparatus of a mobile telephone system capable of solving an acoustic echo and a delay of a predetermined level (24 ms) or more.

1 is a view showing a voice processing apparatus of a mobile communication system according to the prior art;

2 is a diagram illustrating an audio processing apparatus of a mobile communication system according to the present invention.

Explanation of symbols for main parts of the drawings

10: first speech processing unit (DSP vocoder)

20: switching unit (shunt)

30: second voice processing unit 31: CPU

32a, 32b: main echo canceller

33a, 33b: sub echo cancellation unit

34: decoder

In order to achieve the above object, a voice processing apparatus of a mobile telephone system according to the present invention includes a first voice processing unit for removing echoes caused by delays of a predetermined level or less in a voice processing apparatus of a mobile telephone system, and a predetermined level or more. And a switching unit for selecting the first audio processing unit or the second audio processing unit according to a user's request.

Hereinafter, a voice processing apparatus of a mobile telephone system according to the present invention will be described in more detail with reference to the accompanying drawings.

2 is a view showing a voice processing apparatus of the mobile telephone system according to the present invention.

As shown in FIG. 2, the voice processing apparatus of the mobile telephone system according to the present invention includes a first voice processing unit 10 for removing echoes caused by delays below a predetermined level and a delay caused by delays above a predetermined level. A second voice processor 30 for canceling echo and a switching unit 20 for selecting the first voice processor or the second voice processor according to a user's request.

The first voice processing unit 10 is composed of a DSP vocoder that maintains the existing method.

The second sound processor 30 controls the echo cancellation operation of the sub echo cancellers 33a and 33b for canceling the echo from the audio signal and the sub echo cancellers 33a and 33b, and the operation is related to the operation. The main echo canceller 32a and 32b for outputting a signal and the main echo canceller 32a and 32b to download the echo canceller program and control the main echo canceller 32a and 32b. CPU 31 and decoder 34 which designate and decode the addresses of the main echo canceling units 32a and 32b of the CPU 31 and output a signal to the corresponding addresses.

Here, the main echo cancellers 32a and 32b are configured with CEC-128 chips, and the sub echo cancellers 33a and 33b are configured with ECP.

The main echo cancellers 32a and 32b are driven by downloading a driving program from the CPU 31, and remove echoes generated by the hybrid between the wireline telephone and the switch in the PCM data.

The sub echo cancellers 33a and 33b are connected to the main echo cancellers 32a and 32b to remove echoes from the voice signal.

The decoder 34 selects the main echo cancellers 32a and 32b and performs decoding using the lower 16 bits of the 32 bits output from the CPU 31 as logic for outputting a necessary signal. .

The main echo cancellers 32a and 32b download necessary programs from the CPU 31, that is, the main echo cancellers 32a and 32b, to the internal memory through an interface with the CPU 31. The main echo cancellers 32a and 32b perform an echo canceller operation according to a program stored in an internal memory.

In addition, the main echo cancellers 32a and 32b receive clock signals such as a 16 MHz clock, a PCM clock, and a frame synchronization signal.

In the voice processing apparatus of the mobile telephone system according to the present invention configured as described above, when the product manufacturer connects the first voice processing unit 10 and the second voice processing unit 30 through the switching unit 20, the CPU 31 is initialized. After outputting the signal, the drive program is downloaded to the internal memory of the main echo canceller 32a and 32b. At this time, the decoder 34 outputs the necessary signal to the address according to the address output from the CPU 31. Accordingly, the main echo cancellers 32a and 32b control the sub echo cancellers 33a and 33b through a drive program stored in an internal memory and start to perform echo cancellation. For example, in areas where many base stations are installed (domestic or urban areas), voice processing or echo is eliminated using only the DSP vocoder 10, which maintains the existing method, but many foreign base stations are not installed. In rural areas, a problem may occur in removing echoes of 24 ms or more, so that the user USER connects the first voice processing unit 10 and the second voice processing unit 30 through the switching unit 20. Then, the second voice processing unit is performed. The CPU 31 of 30 initializes the second voice processing unit 30 itself as it recognizes the connection with the first voice processing unit 10, and stores the second in the internal memory of the main echo canceling units 32a and 32b. The driving program of the voice processor 30 is downloaded. At this time, the DSP vocoder 10 performs a normal vocoding operation, and the voice signal SI [ 3: 0]) are input to the main echo cancellers 32a and 32b. The main echo cancellers 32a and 32b remove the same signal as the output data component, i. Outputs the signal SO [3: 0] at this time switching 20 in so much when the voice signal is input, a part of the audio signal of which (SI [4: 7]) are sent to the reject sub echo (33a, 33b). The sub echo canceling units 33a and 33b also output the audio signal SO [4: 7] after removing the same signal as that of the output data component, i.e., the echo, compared to the input data SI [4: 7]. In other words, the first voice processing unit 10 of the present invention performs the vocoding operation, and the actual echo canceling operation is performed by the second voice processing unit 30. For example, the echo in which a delay of 24 ms or less occurs is generated in the first voice processing unit. In the speech processing unit 10, echoes having a delay of 24 ms or more are processed by the second speech processing unit 30.

As described above, the voice processing apparatus of the mobile telephone system according to the present invention eliminates echoes caused by delays due to more delays as necessary, in which a delay at which a conventional DSP vocoder can remove echoes is fixed to 24 ms. This can improve the reliability of the product while providing cleaner sound quality.

Claims (4)

In the voice processing device of the mobile telephone system, A first audio processor for removing echoes caused by delays below a predetermined level; A second voice processor for removing echoes caused by delays of a predetermined level or more; And, And a switching unit for selecting the first voice processing unit or the second voice processing unit according to a user's request. The method of claim 1, wherein the second voice processing unit A sub echo cancellation unit for removing echo from the audio signal; A main echo canceller which controls an echo cancel operation of the sub echo canceller and outputs an operation related signal; A CPU for downloading the echo cancellation program to the main echo canceller and controlling the main echo canceller; And, And a decoder configured to designate and decode an address of the main echo canceling unit of the CPU, and output a signal to a corresponding address. The method of claim 2, The main echo canceller is a voice processing device of a mobile telephone system, characterized in that consisting of CEC-128. The method of claim 1, And said predetermined level is 24 ms.