Path diversity performance of DS-CDMA systems in a mobile satellite channel

Abstract

We derive easy to compute semianalytical expressions for the bit error rate performance of coherent and differentially coherent binary phase-shift keying direct-sequence code-division multiple-access systems operating in a mobile satellite channel. The channel is modeled as frequency nonselective with diversity gain obtained through path diversity. This is the scenario when a signal is transmitted to all satellites in view, and the received replicas are independently demodulated and combined at the receiving side. Our analysis extends previous results to the case of unequal mean powers and Rice factors in the combined signals: a valid assumption if we consider that the satellites are in view with different elevation angles. Furthermore, the effect of independent shadowing on each diversity branch is also considered.