Patent ID: 7317771
Filing Date: 2008-01-08
Classification: H04B,H04L

Abstract:
1. A method for estimating a plurality of symbols transmitted by a first plurality of transmit antennas at a given emission time or a plurality of symbols subjected to a space-time dispersion coding prior to transmission by said first plurality of transmit antennas over a second plurality of transmission times, the method using signals received by a third plurality of receive antennas, each symbol belonging to a modulation constellation, the method comprising: forming a vector representative of said received signals at a reception time or at a second plurality of consecutive reception times; and searching the closest neighbour of said vector representative of said received signals at the reception time among candidate vectors belonging to a subset of points, representative of any combination of said possible symbols, determined by said modulation constellation of a lattice of points generated by a plurality of generating vectors, the search being limited to a volume around said vector and being carried out by sequentially selecting a coordinate of a candidate vector for each dimension of said lattice of points in a representation associated with said generating vectors, wherein the components of said vector are expressed in a reordered lattice of points obtained by reordering said generating vectors according to an ordering rule prior to said search, the ordering rule being chosen so as to eliminate a higher proportion of candidate vectors for a first dimension of the reordered lattice of points than for a subsequent dimension of the reordered lattice of points to be searched.