A wireless network device for a WLAN comprising: R modulation modules that receive R independent data streams, that modulate the R independent data streams, and that apply a multiplexing matrix to generate M modulated and multiplexed data streams, respectively, where R and M are integers greater than one, wherein each of the R modulation modules comprises: a spatial mapping module that performs spatial mapping of one of the R independent data streams and that generates M spatial data streams, M modulation mapping modules that receive respective ones of the M spatial data streams and that output M sets of tones, and a matrix module, wherein each of the matrix modules is configured to: generate a respective one of the R multiplexing matrices for a respective one of R client stations based on channel conditions between the wireless network device and the R client stations, and apply the respective one of the R multiplexing matrices to the M sets of tones to generate the M modulated and multiplexed data streams, wherein each of the M modulated and multiplexed data streams are converted by a digital-to-analog converter, DAC, to a data stream having analog format; the wireless network device further comprising M summing modules for summing each of the M data streams having the analog format to generate M transmit data streams; and M transmitters that simultaneously transmit the M transmit data streams during a simultaneous downlink transmission, SDT, period, wherein the M transmit data streams are simultaneously transmitted during the SDT period to the R client stations. R modulation modules that receive R independent data streams, that modulate the R independent data streams, and that apply a multiplexing matrix to generate M modulated and multiplexed data streams, respectively, where R and M are integers greater than one, wherein each of the R modulation modules comprises: a spatial mapping module that performs spatial mapping of one of the R independent data streams and that generates M spatial data streams, M modulation mapping modules that receive respective ones of the M spatial data streams and that output M sets of tones, and a matrix module, wherein each of the matrix modules is configured to: generate a respective one of the R multiplexing matrices for a respective one of R client stations based on channel conditions between the wireless network device and the R client stations, and apply the respective one of the R multiplexing matrices to the M sets of tones to generate the M modulated and multiplexed data streams, wherein each of the M modulated and multiplexed data streams are converted by a digital-to-analog converter, DAC, to a data stream having analog format; a spatial mapping module that performs spatial mapping of one of the R independent data streams and that generates M spatial data streams, M modulation mapping modules that receive respective ones of the M spatial data streams and that output M sets of tones, and a matrix module, wherein each of the matrix modules is configured to: generate a respective one of the R multiplexing matrices for a respective one of R client stations based on channel conditions between the wireless network device and the R client stations, and apply the respective one of the R multiplexing matrices to the M sets of tones to generate the M modulated and multiplexed data streams, wherein each of the M modulated and multiplexed data streams are converted by a digital-to-analog converter, DAC, to a data stream having analog format; generate a respective one of the R multiplexing matrices for a respective one of R client stations based on channel conditions between the wireless network device and the R client stations, and apply the respective one of the R multiplexing matrices to the M sets of tones to generate the M modulated and multiplexed data streams, wherein each of the M modulated and multiplexed data streams are converted by a digital-to-analog converter, DAC, to a data stream having analog format; the wireless network device further comprising M summing modules for summing each of the M data streams having the analog format to generate M transmit data streams; and M transmitters that simultaneously transmit the M transmit data streams during a simultaneous downlink transmission, SDT, period, wherein the M transmit data streams are simultaneously transmitted during the SDT period to the R client stations.