Implementation Of The Low Rate Voice Encoding And Decoding Method For Frame Synchronization In Wireless Fading Channel

In modern wireless communication systems, an increasing volume of business with less frequency resources between the apparent contradiction, and the video data. content-based data service almost allocation of channel resources,and the resources for voice communication are very limited.so the speech signal to be transmitted must be compression-coded in order to achieve the purpose of saving the band. While in order to enable the user to get a good reception side decoded speech, the compression coding algorithm should have the characteristics of a good voice quality and shorter delay.Among the many voice compression standard, the ITU-T (International Telecommunication Union) enacted in1996G.729voice codec standards have been very eye-catching. G.729is the United States, France, Japan and Canada several well-known international telecommunications entities jointly developed by the International Telecommunication Union (ITU-T) in November1995formally adopted the G.729.1996years of ITU-T has developed a simplified G.729’s program G.729A, mainly to reduce the computational complexity for real-time implementation. It uses the CS-ACELP coding scheme can be sampled through the64kb/s rate voice signal is compressed to almost undistorted quality8kb/s rate, while the algorithm are only10ms delay, good speech quality, moderate complexity, low latency, etc.. Digital trunking communication system is the ideal voice codec algorithms. In recent years, along with digital signal processing algorithms and devices (DSP chip) for rapid development, implementation and application of speech coder has laid a solid foundation.This paper systematic research on G.729A speech codec protocol, propose a special speech compression codec chip AC48624as the core processor for speech codec system, and its application to the design of wireless communication system.Paper first introduces the more popular voice codec technology, especially for parametric coding technologies were highlighted; then for parametric coding performance of the more prominent G.729voice codec standards analyzed in detail; then analyzes each frame synchronization method class technology, comprehensive comparison of the advantages and disadvantages of various types of frame synchronization technology, a combination of the two proposed by modifying the G.729A frame structure, to achieve frame synchronization method voice system. Further information on the G.729A voice codec chip AC48624works, performance, interface, and then introduces the FPGA IP core microprocessor embedded MicroBlaze features and use, and finally put forward the realization G.729A voice with MicroBlaze and AC48624compression/decompression software and hardware implementation details. In terms of hardware, the hardware circuit design principles are given, and the specific implementation methods and schematics of each part. On the software side, given the overall software flow chart and the main code. System intelligibility of voice quality and clarity are satisfied, fully meet the ordinary telephone call results can be applied to TDMA wireless communication systems.