Abstract

We propose a decentralized space-time multiuser detection scheme based on a fixed canonical space-time coordinate (CSTC) system that captures the essential degrees of freedom in the received signal. The CSTC system is defined by a fixed set of basis signals and eliminates the need for estimating direction of arrivals (DOAs) and delays encountered during propagation, thereby significantly reducing receiver complexity. The CSTC system provides a natural framework for decentralized multi-access interference (MAI) suppression and diversity processing in a lower dimensional subspace. The signal of the desired user is concentrated in a small subset of coordinates, termed active coordinates, while MAI generally occupies a larger set of coordinates. This fact is exploited to develop a framework for designing decentralized coherent detectors based on the linearly-constrained minimum variance (LCMV) criterion. While active coordinates of the desired user are sufficient for maximal diversity exp...