Patent ID: 8432856

Claim:
A method for wireless communications by an access point, comprising: selecting one or more target signal to noise plus interference ratio (SINR) values for one or more spatial streams using a heuristic algorithm, wherein the heuristic algorithm takes into account practical system constraints and modulation and coding schemes (MCS) of the spatial streams, and wherein the heuristic algorithm does not include channel state information (CSI), wherein selecting the one or more target SINR values for the one or more spatial streams using the heuristic algorithm comprises: selecting an MCS for a user with a highest per-stream rate requirement; selecting MCSs for other users so that transmission time for all the users are approximately equal; mapping each of the MCSs to a desired SINR value; calculating a plurality of required transmit power values to achieve the desired SINR value for each of the users based on the heuristic algorithm that takes into account the practical system constraints; and calculating a target SINR value for each of the users based at least on the desired SINR values; and calculating one or more precoding matrices for the spatial streams for one or more frequency tones by an iterative minimum mean square error (MMSE) beamforming algorithm using the target SINR values.