Application of a Joint Source-Channel Decoding Technique to UMTS Channel Codes and OFDM Modulation

This paper describes the application of a joint source channel decoding technique (JSCD) of variable length codes (VLCs), presented at first by Guivarch et al., in the context of future public land mobile telecommunication systems (FPLMTS) involving UMTS channel codes and OFDM modulation. OFDM parameter sets have been adjusted both to the UMTS chip rate and to the selectivity of the urban multipath propagation channel. The application of JSCD to UMTS codes may lead to signal to noise improvements greater than 3 dB. A methodology is also proposed to get soft error patterns attached to the transmission system, including the OFDM modulation and the multipath channel. Thus, several JSCD schemes can be accurately evaluated thanks to an equivalent simplified model.