Patent ID: 7194237

Claim:
A method of simultaneously transmitting signals over a channel between a first device having N plurality of antennas and a second device having M plurality of antennas, the method comprising: processing a vector s representing L signals [s 1 . . . s L ] with a transmit matrix A that is computed to maximize capacity of the channel by multiplying the vector s with the transmit matrix A, wherein the transmit matrix A is equal to VD, where V is an eigenvector matrix for H H H, H is the channel response from the first device to the second device, D=diag(d 1 , . . ., d L ) and |d p | 2 is the transmit power for p=1 to L; and transmitting with a power constraint for each individual transmit antenna path, wherein if N≦M, then D=I·sqrt(P max /N), with I as an identity matrix, such that the power transmitted by each of the N plurality of antennas is the same and equal to P max /N; and if N>M, then D=sqrt(d·P max /N)·I, such that the power transmitted by antenna i for i=1 to N is (d·P max /N)·(VV H ) ii , and d p =d for p=1 to L.