spatial multiplexing (SM)
Spatial multiplexing(SM) is a radio multiplexing technique that is used to increase the data rate in WLANs and can be used as an alternative to multiple input multiple output( MIMO) as part of the 802.11n standardization.
Under certain conditions, the data rate with spatial multiplexing increases linearly with the number of antennas. Spatial multiplexing is spatially offset multiplexing that uses a multi- antenna system to transmit multiple spatial streams( SS) simultaneously. In 802.11 wireless LANs, the four frequency bands of 10 MHz, 20 MHz, 30 MHz or 40 MHz can be used and data rates of 315 Mbit/s to 630 Mbit/s can be transmitted over them.