Application Of G.723.1 Speech Codec Technology For Power Line Carrier Communication

Power line carrier communication is a specific technology, and it has extensive application in power system. In our country the carrier frequency is from 40 to 500kHz and divided into 115 channels of 4kHz. With the increasing demanding, we need to use DPLC to transmit multiple speech and data signals in every channel. And the rapidly developing DSP technology provides a powerful solution to speech signal processing and digital modulation/demodulation, which makes it possible to implement all kinds of complex algorithms in real time.The paper introduces briefly the principles and digital technology of power line carrier (PLC) communications. According to OFDM technology adopted by our DPLC multiplexer, we choose the lower bit rate scheme of G.723.1 to compress speech signals in order to transmit two path speech signals and 2~4 path data signals in one channel. This paper introduces the principle and realization of G.723.1 speech codec. We choose TMS320C5409 DSP chip to implement speech compression scheme, and optimize the code of G.723.1 in order to realize real time codec of two path speech signal on one DSP chip. In the end the paper introduces the simulated implementation of speech compression in the multiplexer we designed.