Low complexity soft output MIMO decoder

摘要

A method and processing block for receiving data transmitted in a MIMO system is provided. Data is transmitted as a transmit vector of values from multiple transmitting antennas and received as a receive vector of values at multiple receiving antennas. Candidate vectors are determined based on each of a plurality of constellation points of the constellation configuration used in the transmission scheme. A channel matrix is decomposed into a unitary matrix and a triangular matrix, such that a relationship links: (i) a function of the unitary matrix and the receive vector, and (ii) a multiplication of the triangular matrix and the transmit vector. A best candidate vector from the set of candidate vectors is utilized for the computation of soft bits representing the values of the transmit vector.

主权项

1. A method of receiving data transmitted in a MIMO system, wherein the data is transmitted from a transmitter over a MIMO channel as a transmit vector comprising a plurality of values, the method comprising:
receiving the data as a receive vector comprising a plurality of values, the data being received over the MIMO channel at a receiver in which the MIMO channel is represented as a MIMO channel matrix decomposed into a combination of a unitary matrix and a triangular matrix, wherein there is a relationship linking: (i) a function of the unitary matrix and the receive vector, and (ii) a multiplication of the triangular matrix and the transmit vector; determining a set of candidate vectors for representing the transmit vector by: for each of a plurality of constellation points, setting a particular value of a corresponding candidate vector to that constellation point and using the relationship and the particular value which is set to map other values of the candidate vector to constellation points, thereby determining the set of candidate vectors in which the particular value within the candidate vectors is set to be respective ones of the constellation points; determining further sets of candidate vectors by: permuting columns of the MIMO channel matrix which represents the MIMO channel, decomposing the MIMO channel matrix into a further unitary matrix and a further triangular matrix, and repeating said determining a set of candidate vectors, this time based on the permuted MIMO channel matrix; and using the sets of candidate vectors determined from the MIMO channel matrix and the permuted WINO channel matrix at the receiver to determine soft bits representing the plurality of values of said transmit vector.