Puncturing of Turbo Codes According to Importance of Packet Data of Source Coder(CS-ACELP)
Man Jong Jang, In Seong Lee · 1999
In this paper, we propose the turbo codes combined with the CS-ACELP speech coder. The CS-ACELP and turbo codes are being considered as speech coder and channel coder of IMT-2000 system. The CS-ACELP is 8 kbps transmission rate. The code rate of channel coder is given by 1/2. Usually, 1/2 rate turbo codes is obtained by uniformly puncturing 1/3 rate turbo codes. however, In this paper, the puncturing methods according to importance of the output packet data of the source coder is proposed for the turbo codes. The importance of the output packet data is analyzed by checking the sensitibity of speech parameters to channel errors. The sensitivity of source coder output packet data is measured in noisy channel. the simulation is executed over Rayleigh fading channel. The performance improvement of proposed puncturing method was verified in the informal subjective listening test and MOS test.