Limiting candidates for symbol detection in a MIMO communication system

A circuit for detecting symbols communicated between multiple transmitting antennas and multiple receiving antennas, comprising:

• respective distance blocks associated with the transmitting antennas and coupled in a sequence according to an ordering of the transmitting antennas, wherein the respective distance block associated with each transmitting antenna determines a distance value for each of a first plurality of pairings, each pairing being one of one or more candidates and one of a plurality of symbols in a constellation;
• a respective selector block coupled between each successive first and second one of the distance blocks in the sequence, the respective selector block configured to select a second plurality of candidates for the second distance block from the first plurality of pairings of the first distance block, wherein the second plurality of candidates is a limited number of the first plurality of pairings having smaller ones of the distance values;
• a limit block coupled to each selector block, wherein the limit block provides the limited number to each selector block;
• and
• an identifier block coupled to a last one of the distance blocks in the sequence, wherein the identifier block selects the pairing having a smaller one of the distance values from the first plurality of pairings of the last distance block.

A program storage medium, comprising:

• a processor-readable device configured with instructions, wherein execution of the instructions by one or more processors causes the one or more processors to perform operations including generating configuration data for a programmable logic device that implements,
• respective distance blocks associated with the transmitting antennas and coupled in a sequence according to an ordering of the transmitting antennas, wherein the respective distance block associated with each transmitting antenna determines a distance value for each of a first plurality of pairings, each pairing being one of one or more candidates and one of a plurality of symbols in a constellation;
• a respective selector block coupled between each successive first and second one of the distance blocks in the sequence, the respective selector block configured to select a second plurality of candidates for the second distance block from the first plurality of pairings of the first distance block, wherein the second plurality of candidates is a limited number of the first plurality of pairings having smaller ones of the distance values;
• a limit block coupled to each selector block, wherein the limit block provides the limited number to each selector block;
• and
• an identifier block coupled to a last one of the distance blocks in the sequence, wherein the identifier block selects the pairing having a smaller one of the distance values from the first plurality of pairings of the last distance block.