Antenna switching in frequency bands with power spectral density (PSD) limits

This disclosure provides methods, devices and systems for improving wireless communications in power spectral density (PSD)-limited frequency bands. A wireless communication device, having a number (NTX) of transmit antennas, parses a physical layer (PHY) protocol data unit (PPDU) into a number (NSS) of spatial streams and modulates the NSS spatial streams on a number (M) of subcarriers. In some implementations, the wireless communication device may transmit the PPDU using a number (N) of the transmit antennas, where NSS < N < NTX. In some other implementations, the wireless communication device may subdivide the M subcarriers into subcarrier groups and may transmit each subcarrier group using a respective subset of the NTX transmit antennas, where the number of transmit antennas used to transmit each subcarrier group is greater than or equal to the number of spatial streams modulated on the subcarriers in the group but less than NTX.