Patent ID: 9124459
Filing Date: 2015-09-01
Classification: H04L

Abstract:
1. An apparatus for sphere decoding of signals for Multiple Input Multiple Output (MIMO) detection, to deduce an actual transmit symbol vector from a received symbol vector, the apparatus comprising: a first distance processor configured to repeatedly determine a distance between a received symbol vector and a transmit symbol vector including a current symbol transmitted from one of transmit antennas, for different possible transmit symbols standing for the current symbol, in a search sequence according to a search tree whose each level corresponds to possible transmit symbols for a symbol transmitted by a specific one of the transmit antennas, wherein said received symbol vector comprises a received symbol for each receiving antenna following the transmit antenna transmitting the actual transmit symbol vector; a first unit configured to determine a total distance for a possible transmit symbol vector based on a set of distances determined for different ones of the transmit antennas, a comparator configured to compare the total distance to a threshold, to determine whether to stop the search sequence; a second unit configured to determine a next symbol in the search sequence for distance processing, the next symbol being at a different level in the search tree than the symbol currently being processed by the first distance processor; and a second distance processor configured to repeatedly determine the distance in respect of the next symbol in parallel with the first distance processor determining of the distance in respect of the current symbol, before the total distance is determined.