DISTANCE-LEVEL COMBINING FOR MIMO SYSTEMS WITH HARQ AND/OR REPETITION CODING

摘要

Systems and methods are provided for decoding signal vectors in multiple-input multiple-output (MIMO) systems, where the receiver has received one or more signal vectors from the same transmitted vector. For each received signal vector, the receiver evaluates a decoding metric using each possible value of the transmitted signal vector to produce a set of distances. The receiver then combines distances from across the received signal vectors to produce a combined distance associated with each possible value of the transmitted signal vector. Using the combined distances, the receiver may choose among the possible values of the transmit signal vector to determine the actual transmit signal vector. Maximum Likelihood (ML) metrics are proposed for Hybrid ARQ type 1. QR decomposition and ZF equalization are envisaged to simplify the computation of the metrics.