On the performance of chip-interleaved turbo coded DS-CDMA system under impulse noise

In this paper, the performance of turbo coded asynchronous direct-sequence code division multiple access (DSCDMA) system is evaluated under impulsive noise environment. Two different system models are considered. The first system is one in which message bits are encoded and then spread using a pseudo noise (PN) sequence. The second system is one where the message bits are first spread by a PN sequence and the resultant chip sequence is then chip-by-chip encoded. The output sequences in both cases are chip interleaved to combat the detrimental effects of impulse noise. The results show that the second system model, which is chip-by-chip encoded, gives better error performance for all number of users. This improved performance, however, comes with higher decoding complexity.