Patent ID: 8681644

Claim:
A method for communications device operations, the method comprising: receiving transmissions from at least two access points; measuring channels between the communications device and each of the at least two access points in accordance with the received transmissions; computing beamforming weights in accordance with the measured channels, wherein the computing is in accordance with attempting to maximize a capacity of a communications system containing the communications device and the at least two access points with the beamforming weights, and wherein the attempting to maximize the capacity comprises computing a value of a cost function in accordance with the measured channels and the beamforming weights, and determining a convergence of the value of the cost function; transmitting the beamforming weights to the at least two access points; and receiving coordinated multi-point (CoMP) transmissions from the at least two access points, wherein each of the (CoMP) transmissions is beamformed using one of the beamforming weights, and wherein the at least two access points comprises first and second access points, each having two transmit antennas, wherein the communications device includes two antennas, and wherein computing beamforming weights comprises determining w 1 and w 2 such that a capacity function expressible as C max = max w 1 , w 2  w 1  = 1 ,  w 2  = 1 ⁢ C ⁡ ( w 1 , w 2 ) is maximized, where w 1 and w 2 are the beamforming weights, and C is the capacity of the communications system and is expressible as C ( w 1 ,w 2 )=log 2 det( I 2 +H H H ), where H = [ P 1 · h 11 H ⁢ w 1 P 2 · h 12 H ⁢ w 2 P 1 · h 21 H ⁢ w 1 P 2 · h 22 H ⁢ w 2 ] , I 2 is an identity matrix, h 11 H and h 21 H are downlink channel vectors from the first access point to a first antenna and a second antenna of the communications device, respectively, h 12 H and h 22 H are downlink channel vectors from the second access point to the first antenna and the second antenna of the communications device, respectively, and P 1 and P 2 are total transmit power to the communications device from the first access point and the second access point, respectively.