Patent ID: 8045652
Filing Date: 2011-10-25
Classification: H04L

Abstract:
1. A method for communication, comprising: receiving a spatially-multiplexed signal using multiple receivers to produce multiple respective received signals, the spatially-multiplexed signal comprising multiple simultaneously-transmitted symbols, which are selected from respective sets of constellation symbols, each constellation symbol representing a respective set of values of a group of data bits; iteratively traversing combinations of the constellation symbols, wherein each combination comprises one constellation symbol from each of the sets of the constellation symbols and represents N data bits, and wherein each combination is traversed at most once, and searching the traversed combinations for a combination that matches the received signals; during traversal of the combinations of the constellation symbols, accumulating at least 2N measures of likelihood regarding the values of the data bits represented by each traversed combination; processing the accumulated measures of likelihood, which were computed by traversing each combination at most once, to produce soft bit metrics; and reconstructing the values of the data bits carried by the multiple transmitted symbols responsively to the soft bit metrics, wherein traversing the combinations comprises defining a stopping condition, and terminating traversal of the combinations responsively to meeting the stopping condition, and wherein traversing the combinations comprises calculating for each traversed combination a first solution metric that is indicative of a distance between the traversed combination and the received signals and a second solution metric that is indicative of a distance between one of the constellation symbols in the traversed combination and one of the received signals, and wherein terminating the traversal comprises terminating the traversal when the second solution metric exceeds a best achieved value of the first solution metric by a predetermined threshold.