Packet error rate analysis and its reduction by known bits insertion for turbo code in 10OMbps OFCDM system

This paper investigated the PER and throughput performance of known bits insertion scheme for turbo code in 100 Mbps OFCDM(orthogonal frequency and code division multiplexing) in AWGN and multipath Rayleigh fading channels. The method 1 in which the information rate is reduced by replacing information bits by inserted known bits gives 8% throughput increase. The method 2 in which the information rate is fixed irrespectively of the number of inserted known bits by changing the number of punctured bits in order to get the fixed total FEC coding rate also gives PER and BER improvement compared with the conventional turbo code without known bits insertion when the number of inserted known bits are optimized.