Precoding Matrix Index selection process for a MIMO receiver based on a near-ML detection, and apparatus for doing the same

摘要

A Process for selecting a Precoding Matrix Index (PMI) in a Multiple In Multiple Out (MIMO) receiver of a wireless communications comprising a base station communicating with User Equipments through a downlink and uplink channel, said base station applying a precoding on the transmit symbol vector based on a matrix Pi being selected from a set of predefined matrices and identified by a PMI index computed by said UE and forwarded to said base station via said uplink ; said process involving step of:
- estimating (100) the MIMO channel matrix H of a given set of resources blocks comprising received symbol vectors;
- estimating (200) the variance à 2 of the additive noise (AWGN)
- computing (300) for each particular matrix comprised within said set of predefined matrix a cost function Fi (Pi, H, Ã 2 n ) being representative of the orthogonality of said matrix MIMO channel matrix H;
- comparing (400) the values of said cost function Fi; and
- transmitting (500) to said base station the index i corresponding to the Fi representative of the best conditionned MIMO channel matrix.