Design and analysis of concatenated coded DS/CDMA systems in asynchronous channels

We propose and analyze concatenated coding schemes for direct-sequence code-division multiple-access (DS/CDMA) systems in asynchronous channels. In the concatenated coding, bandwidth-efficient 2/sup 2L-2/-state L/(L+1)-rate 2-MTCM with biorthogonal signal constellation is used for the inner code, and (2/sup L/-1,[(2/sup L/-1)/L/2]) RS code is used for the outer code. It is shown that we can get considerable performance gain over the uncoded system without sacrificing the data transmission rate. The proposed system can be used as a coding scheme for reliable and high-speed integrated information services of mobile communication systems.