Patent ID: 7254184

Claim:
A method of closed-loop multi-stream wireless communication between transmitter means comprising a transmit antenna array of a plurality of N transmit antenna elements and receiver means comprising a receive antenna array of a plurality of M receive antenna elements, wherein a plurality of distinct data streams (x 1 , x 2 ) are transmitted from said transmit antenna array to said receive antenna array and said data streams are weighted by respective complex weighting matrices before being applied to said transmit antenna array, said distinct data streams being separated and estimated at said receiver means, the method comprising: applying said distinct data streams (x 1 , x G ) to respective sub-groups of said transmit antenna elements at least one of which comprises a plurality of said transmit antenna elements, each of said sub-groups comprising at least N d transmit antenna elements, where M is greater than or equal to (N/N d ), said complex weighting matrices (v 1 to v n ) being functions of the respective transmission channels (h ij ) of said data streams (x 1 , to x G ) between each of the plurality of N transmit antenna elements and each of the plurality of M receive antenna elements including the respective sub-groups of transmit antenna elements.