High capacity high performance DS-CDMA via advances in chip shaping

This paper introduces a novel chip shaping scheme increasing the network capacity in DS-CDMA systems without any increase in. bandwidth or chip rate, and without performance degradation. The chip shape corresponds to an interferometry pattern created by the superposition of N carriers. Two sets of orthogonal chip shapes with minimum inter-chip interference are positioned pseudo-orthogonally (in time) within a single symbol duration, allowing the novel system to support many more chips in the same symbol duration and bandwidth. Simulations performed over Rayleigh fading channels indicate the new chip shaping (and corresponding detection strategy) enables 100% gains in DS-CDMA network capacity without any loss in performance. With the exception of chip shape and receiver design, this new system retains all the features of a conventional DS-CDMA system.