Precoding for improved performance of Welch-bound signature sets

Abstract

Welch-bound signature sets are optimal for oversaturated synchronous CDMA in terms of minimizing the multiple access interference. In this paper, precoding of the sum signal of Welch-bound signatures, in order to maximize the mean signal-to-interference ratio for conventional receivers, is analysed. The gain compared to normal sum signal is calculated, and also the effect on the energy of the sum signal is derived.