KR20030077209A - Bypass packet for vocoder - Google Patents

Abstract

PURPOSE: A bypass packet of a vocoder is provided to be written on the basis of a bypass packet of a vocoder having the highest data rate among currently-used vocoders, thereby being commonly used for various vocoder boards with easy development and maintenance. CONSTITUTION: Information on a system and vocoders is written in a header region. A starting position is fixed, size of a region is set on the basis of a vocoder having the highest data rate among currently-used vocoders, and voice compression data is written in a data region. The starting position is fixed, and a CRC code for correcting detected errors is written in a checksum region. The data region includes indication data for indicating the starting position of the checksum region, and includes information presenting length of the indication data.

Description

Vocoder bypass packet {BYPASS PACKET FOR VOCODER}

The present invention relates to a bypass packet of a vocoder, and more particularly, to a bypass packet of a vocoder which can be commonly used in various types of vocoder.

In general, vocoding consists of a process of decomposing and transmitting a speech signal into several parameters and a process of synthesizing the original speech signal by extracting and analyzing the transmitted parameters.

A representative example of the vocoding scheme is an LPC vocoding scheme using a linear prediction coding scheme. The principle of the LPC vocoding scheme is that a predetermined number of previous speeches are based on a strong correlation between signals. By linearly combining the signal samples to predict other voice signal samples.

Not only the LPC-based vocoder but also the voice signal can be used for all Parametic Coders based on Speech Production Model.

The Parametic Coder does not transmit a voice signal itself but extracts and transmits parameters based on a voice generation model.

Here, the bypass packet used for the vocoder is a technology applied to improve the sound quality in Mobile-To-Mobile calls using the same vocoder, and has been implemented with its own standard for each service company. Packet functions are not compatible with each other because the same standard is not applied than the difficulty of implementation.

The bypass packet function applied to the Mobile-To-Mobile call transmits the vocoded voice packet from the mobile to the other mobile, thereby improving the sound quality by eliminating the degradation of the sound quality due to the double vocoding.

FIG. 1 is a schematic diagram of an 8K GCELP bypass packet, which includes a header region, a data region, and a checksum region, and FIG. 2 is a schematic diagram of a 13K GCELP bypass packet, as shown in FIG. It consists of a checksum area.

At this time, the size of the data area is set to vary according to the data rate of the vocoder.

That is, since the configuration of the bypass packet is different for various types of vocoder depending on the system developer and service company, the bypass packet must be developed for each vocoder separately, and the mobile communication system is used for 2G, CDMA1X, and 3G. As the system evolves, there is a problem in that the bypass packet needs to be redeveloped for each system because it is not compatible with the existing system.

The present invention has been made to solve the above problems, the bypass packet is created based on the bypass packet of the vocoder with the highest data rate among the vocoders currently used, so that it can be used on all vocoder boards. The purpose is to provide a vocoder bypass packet.

1 is a schematic representation of an 8K GCELP Bypass Packet.

2 is a schematic representation of a 13K GCELP Bypass Packet.

3 is a schematic diagram of a bypass packet of the vocoder of the present invention.

According to an aspect of the present invention, there is provided a bypass packet for transmitting a voice packet encoded in a mobile device to an opposite mobile device, comprising: a header area in which information about a system and a vocoder is written; A data area in which the start position is fixed, the size of the area is set based on the vocoder with the highest data rate among the currently used vocoder, and the speech compressed data is written; The start position is fixed, and a checksum area is written in which a CRC code for detecting and correcting an error is written.

Hereinafter, the operation and effects of the vocoder bypass packet according to the present invention will be described in detail with reference to the accompanying drawings.

First, the inventors of the present application will note that the bypass packets shown in FIGS. 1 and 2 are similar in the following points.

First, the start and end of the header area are almost identical, so the size is almost the same.

Second, the size of the checksum area for detecting errors is almost the same, but only the size of the data area varies greatly depending on the type of vocoder.

Therefore, the applicant of the present invention devised a single bypass packet that is used regardless of the type of vocoder.

Only, the data area of the bypass packet that is variable according to the type of vocoder is fixed, that is, the data area is allocated to be suitable for the maximum data rate of the vocoder, and the start position of the header area and the checksum area of the bypass packet is determined. Fix it.

Therefore, if the bypass packet is newly defined, all vocoders currently being developed will perform a function of compressing and restoring voice data.

That is, the following disadvantages described above will be solved by the present invention.

As the mobile communication system evolves to 2G, CDMA1X, and 3G systems, the bypass packet used for the vocoder of the system is not compatible with the existing system, and the bypass packet must be developed for each system. The efficiency is lowered.

Therefore, the proposed bypass packet can be easily applied to various vocoder boards and is easy to develop and maintain.

Here, referring to FIG. 3, the bypass packet includes a header area in which information about the system and vocoder is written, a start location is fixed, a data area in which voice compressed data is written, and a start location is fixed. A checksum area is written in which a CRC code for detecting and correcting a symbol is written.

The header area or data area may include indication data indicating start positions of the data area and the checksum area.

Here, the header area is composed of preamble data indicating a bypass packet and information on a serial number area for a packet counter. The header area includes a maximum of about 10 bytes.

In addition, the checksum area is used for error detection of the bypass packet, and is configured in a maximum of about 10 bytes.

The size of the data area is set based on the vocoder with the highest data rate among the vocoders currently used.

The data area may include keypad data, short message service (SMS) data, status data, and indication data included in the PID data frame. Information indicating the length of these data may be included in the header area or the data area.

The status data is antenna and battery status information, and the indication data is data for indicating a user's name.

From the moment the vocoder is input, the vocoder analyzes the bypass packet to perform error correction and voice data restoration. The bypass packet shown in FIG. 3 is a 13K QCELP having the highest data rate among the vocoder. This is based on WB-ARM. If you consider WB-ARM, you can extend the concept based on WB-ARM.

That is, when transmitting a bypass packet, previously, a bypass packet having a different structure for each vocoder was developed and transmitted, but now it is applicable to all vocoders as one unified bypass packet.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications may be made without departing from the scope of the present invention.

Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the scope of the following claims, but also by the equivalents of the claims.

As described in detail above, the present invention creates a bypass packet based on the bypass packet of the vocoder with the highest data rate among the vocoders currently being used, and can be used on various vocoder boards without any difficulty, and further development. And easy maintenance is effective.

Claims (3)

In the bypass packet for transmitting the voice packet encoded in the mobile to the other mobile, A header area in which information about the system and the vocoder is written; A data area in which the start position is fixed, the size of the area is set based on the vocoder with the highest data rate among the currently used vocoder, and the speech compressed data is written; A bypass packet of a vocoder comprising a checksum area in which a start position is fixed and a CRC code for detecting and correcting an error is written. The method of claim 1, wherein the data area, A bypass packet of a vocoder, comprising: indication data indicating the start position of the data area and the checksum area; and information indicating the length of the indication data. The method of claim 1, wherein the header area, A bypass packet of a vocoder, comprising: indication data indicating the start position of the data area and the checksum area; and information indicating the length of the indication data.