Patent ID: 8059761

Claim:
A circuit for detecting communications from multiple transmitting antennas to multiple receiving antennas, wherein an ordering of the transmitting antennas begins with an initial transmitting antenna and ends with a last transmitting antenna, and the ordering includes at least one non-initial transmitting antenna other than the initial transmitting antenna, the circuit comprising: for the initial transmitting antenna, first means for determining partial distances for a first plurality of pairings of a null candidate and one of a plurality of combinations of a plurality of quadrature-phase values and a plurality of in-phase values; for each non-initial transmitting antenna, second means for determining partial distances for a second plurality of all pairings of one of a first plurality of candidates and one of the quadrature-phase values of a constellation, the second plurality of pairings including a respective set for each first candidate that includes the second pairings of the first candidate and each quadrature-phase value, and a first one of the second means for determining coupled to the first means for determining; for each non-initial transmitting antenna, third means for determining partial distances for a third plurality of all pairings of one of a second plurality of candidates and one of the in-phase values of the constellation; for each non-initial transmitting antenna, first means for selecting the first plurality of candidates from the first and third pluralities of pairings for a preceding transmitting antenna in the ordering, a first one of the first means for selecting coupled to the first means for determining and to the first one of the second means for determining; for each non-initial transmitting antenna, second means for selecting the second plurality of candidates from the second plurality of pairings of the non-initial transmitting antenna, wherein, for each first candidate of the non-initial transmitting antenna, one of the second plurality of candidates is selected to be one of the second pairings that has the partial distance that is smaller in the respective set for the first candidate, and a first one of the second means for selecting coupled to the first one of the second means for determining and to a first one of the third means for determining, a last one of the second means for selecting coupled to a last one of the second means for determining and to a last one of the third means for determining, and a last one of the first means for selecting coupled to a previous one of the third means for determining and to the last one of the second means for determining; and third means, coupled to a last one of the third means for determining, for selecting a final candidate from the third plurality of pairings of the last transmitting antenna, wherein the final candidate is the pairing in the third plurality having the partial distance that is smaller.