Blind Reduced-Rank Receiver with Column Adaptation for DS-UWB Systems Based on Joint Iterative Optimization and CCM Criterion

A novel linear blind reduced-rank receiver based on the Joint Iterative Optimization (JIO) and the constrained constant modulus (CCM) design criterion is proposed for interference suppression in direct-sequence ultra-wideband (DS-UWB) systems. The proposed receiver consists of a projection matrix that performs dimensionality reduction and a reduced-rank filter that produces the output. The columns of the projection matrix and the reduced-rank filter are updated jointly at each time instant or iteration to minimize the CM cost function subject to a constraint. Recursive least-squares (RLS) algorithms are developed for the adaptive implementation. Simulation results show that the proposed scheme has excellent performance in suppressing the inter-symbol interference (ISI) and multiple access interference (MAI) with a low complexity.