Burst-Error Correction Strategies in a Slotted DS-CDMAMobile Satellite Channel

Abstract

Various burst-error handling strategies exist to reduce the effects of bursts of errors such as those that characterise a heavily shadowed, slowly fading land mobile satellite channel using low earth orbit satellites (LEOS). It is proposed that a combination of the techniques with code rate adjustment and channel-state sensing leads to high performance gains for the direct sequence CDMA channel. This paper presents studies of the performance of code interleaving in co-ordination with code rate reduction in a channel with known burst statistics where provision is made for channel-state sensing. The results are compared with those from concatenated coding and hybrid automatic repeat request (hybrid ARQ) with selective repeat (SR). Results are presented for throughput and delay. The combination of the various techniques for specific channel conditions results in significant performance improvements in terms of throughput and average time delay. The proposed error-control technique offers significant performance gains over the use of hybrid ARQ, concatenated coding or interleaving in isolation.