Analysis of decoding order and rate allocation with successive interference cancellation in DS-CDMA systems

This paper analyzes the problem of decoding order and rate allocation in DS-CDMA cellular systems using successive interference cancellation (SIC) technology. Two different constraints, i.e. the maximum transmission power of users and the system throughput, are considered respectively. When the maximum transmission power of users is limited, this paper first proposes a theorem to assert whether or not the system is feasible, and then the optimal decoding order algorithm based on the feasible solution is given for some special cases. When the system throughput is an issue, the rate allocation should also be considered besides the decoding order. In this case, an algorithm to find the optimal solution is given first, and then a suboptimal solution is given to reduce the computation complexity. Different user cost factors are considered in both cases, and the methodologies and corresponding results of the analyses can be used as a reference to real system operating, access control and scheduling, etc