The capacity improvement of an integrated successive decoding and power control scheme

The application of multiuser detection and interference cancellation techniques can greatly increase the capacity of wireless networks. In the present paper we focus on successive decoding DS-CDMA systems. By successively decoding the strongest user and canceling it from the received signal in decreasing received power order, the in-cell interference is minimized. In a multicellular environment, the other-cell interference can be greatly reduced by employing the proposed power control scheme. The simplified analytical model has shown a reverse-link capacity gain of 2.26 over the conventional DS-CDMA system, under the assumptions of no lognormal shadowing, uniform user density, and taking a deterministic number of active users based on the mean voice activity level. With added complexity of lognormal shadowing, binomially distributed active users, the detailed simulation model has shown a capacity gain of 2 over the conventional system. Both models are under the assumption of perfect interference cancellation and negligible decoding errors.