An estimation-based approach to multiple-input multiple-output (MIMO) channel equalization

摘要

The purpose of this paper is to propose and investigate a new approach to implementing a spatio-temporal decision feedback equalizer (DFE) for MIMO (multiple-input multiple-output) channels. A system with an array of n transmit and m receiver antennas where (m ≥ n) is assumed. Both finite-length (finite horizon) and infinite-length\ud(infinite horizon) MIMO decision feedback equalizers are considered. We also assume an ISI (inter-symbol-interference) MIMO channel, which means\udthe channel matrix elements are frequency selective. \ud\udFor the infinite-length case the DFE problem leads to solving a matrix spectral factorization. For the finite-length case the DFE problem leads to solving a corresponding Cholesky factorization. \ud\udUsing the estimation-based spectral factorization we have shown that the solution to the infinite-length MIMO DFE is not unique. In the finite-length case the estimation-based approach leads to a recursive algorithm to perform\udthe Cholesky factorization. The proposed recursive algorithm has low complexity and is also simple to implement. Moreover it leads to a\udclosed form solution for the MIMO DFE matrices.