Low complexity optimal soft MIMO receiver

摘要

A low-complexity optimal soft MIMO detector is provided for a general spatial multiplexing (SM) systems with two transmit and NR receive antennas. The computational complexity of the proposed scheme is independent from the operating signal-to-noise ratio (SNR) and grows linearly with the constellation order. It provides the optimal maximum likelihood (ML) solution through the introduction of an efficient Log-likelihood ratio (LLR) calculation method, avoiding the exhaustive search over all possible nodes. The intrinsic parallelism makes it an appropriate option for implementation on DSPs, FPGAs, or ASICs. In specific, this MIMO detection architecture is very suitable to be applied in WiMax receivers based on IEEE 802.16e/m in both downlink (subscriber station) and uplink (base station).

主权项

1. A method of performing a linear-complexity optimal soft Multiple-input-multiple-output (MIMO) detector, the method comprising the steps of:
calculating first and second generator matrices based upon a channel matrix; applying the generator matrices to a received vector to generate first and second modified received vectors wherein the first modified received vector comprises an original transmitted vector and the second modified received vector comprises a flipped version of the original transmitted vector; selecting first and second elements of the transmitted vector as child and parent symbols respectively; determining, for both the transmitted vector and the flipped version of the transmitted vector, for each possible value of the parent symbol, a first child; and calculating log-likelihood ratios (LLRs) of all bits for each resulting vector.