Patent ID: 8774146

Claim:
A method performed by a base station in a cellular network in which the base station serves a population of same-cell terminals, the cellular network includes other base stations that serve respective populations of other-cell terminals, the terminals are allocated to two or more terminal groups, each terminal group is a reuse group for pilot signals transmitted by terminals, and each terminal Within a given cell belongs to a respective terminal group; the method comprising: obtaining a message destined for each of one or more same-cell terminals; further obtaining a message destined for each of one or more other-cell terminals belonging to each of two or more terminal groups; linearly combining the messages destined for the same-cell and other-cell terminals of each terminal group, thereby to form a pilot contamination precoded message for each terminal group, wherein the linear combining is performed using a set of slow-fading coefficients; performing beam-forming precoding on the pilot contamination precoded messages using a set of fast-fading coefficients; and transmitting the pilot contamination precoded messages synchronously with the other base stations, wherein the transmitting is performed using multiple antennas, fast-fading coefficients apply only to same-cell terminals, slow-fading coefficients apply to same-cell and to other-cell terminals and the fast-fading coefficients are updated more frequently than the slow-fading coefficients.