Method and arrangement for generating soft bit information in a receiver of a multiple antenna system

Abstract

The invention which relates to a method and to an arrangement for generating soft bit information in a receiver of a multiple antenna system is based on the object of reducing the calculation complexity for generating the soft bit information. In terms of the method, the object is achieved by virtue of the fact that the iterative deepening search for the Mh antenna is carried out in two substeps, in which case, in the first substep, when the last element of s is not assigned to the mth antenna, s is rotated in such a manner that m is associated with the last element of s, that the channel matrix H is likewise rotated and QR decomposition of the channel matrix H is carried out, that, in the second substep, the iterative deepening search is carried out using a search radius in the form of a vector (Formula (I)); in which (Formula (II)) denotes the number of bit positions in the mth antenna, that the comparison (Formula (III))≧dis carried out for a search radius vector (Formula (IV)) and the search radius is adapted by setting the vector element (Formula (IV)) ( . . . ) of the search vector (Formula (IV)) to the value of the Euclidean distance corresponding to the condition satisfied, that the iterative deepening search is carried out as long as at least one search radius (Formula (IV)) ( . . . ) from the radius vector (Formula (IV)) satisfies the condition (Formula (III))≧dor the comparisons with all of the transmission symbols s(m) of all Nantennas have been carried out, that the soft bit information (Formula (V)) for the antenna m is output, and that the substeps of the method are run through again until all of the soft bit information (Formula (V)) has been determined for all Nantennas.