Patent ID: 8290082

Claim:
A method for signal communication in a multi-user radio communication system including a transmit station, having N>1 transmit antennas, and Uâ‰§2 receive stations, each receive station having at least one receive antenna and the summed number S of receive antennas of receive stations satisfies 1<Sâ‰¦N, wherein signals are transmitted-received by means of Fâ‰§1 physical channels, the method comprising: estimating transfer coefficients of all possible spatial communication channels respectively; and transmitting signals by the transmit station and receiving signals by receive stations using F physical channels, wherein the step of transmitting signals by the transmit station comprises: forming a channel matrix H of the physical channel using estimates of spatial channel transfer coefficients; forming a real-valued vector a r and matrix H r using a transmitted modulation symbol vector a and the channel matrix H; forming a linear multi-user transformation matrix W r using the real-valued vector a r ; generating a perturbed real-valued vector of transmitted modulation symbols by adding the real-valued transmitted modulation symbols vector to an optimal perturbing vector; determining the optimal perturbing vector in such a way as to minimize the transmitted signal power; forming a vector of transmitted signals x by multiplying a non-normalized transmitted signals vector x 0 by a normalizing coefficient C T ; and transmitting a set of signals corresponding to the elements of the obtained vector x over an appropriate physical channel via all transmit antennas, wherein the step of receiving signals by receive stations comprises: receiving signals at each of U receive stations in a physical channel of each receive antenna; wherein the reception is carried out in such a way that a signal y is formed as a complex number with a modulo and an argument corresponding to the amplitude and phase of the signal received by this physical channel; normalizing signal y by multiplying it by a normalizing coefficient C R , thus forming a normalized signal y norm =yÂ·C R ; obtaining real and imaginary parts of the normalized signal y norm as z=Re y norm , c=Im y norm , performing a modulo operation by modulo A for resulting signals z and c; z ~ = z - A â¢ âŒŠ z + A / 2 A âŒ‹ c ~ = c - A â¢ âŒŠ c + A / 2 A âŒ‹ , where â””xâ”˜ is an integer part of x, comprising the maximum integer less than x, the signals {tilde over (z)} and {tilde over (c)} are used to form a complex signal {tilde over (y)}={tilde over (z)}+j{tilde over (c)} , and forming values of a complex signal {tilde over (y)} in each physical channel of each receive antenna are used to demodulate and decode the received signal.