Antenna/beam selection training in MIMO wireless LANS with different sounding frames

A station in a multiple-input, multiple-output (MIMO) wireless local area network (WLAN) including a plurality of stations, each station including a set of antennas, said station comprising:

• a receiver configured to receive, via a channel, plural consecutive packets including plural sounding packets, each sounding packet corresponding to a different subset of the set of antennas, and at least one of the plural consecutive packets including (i) a high throughput (HT) control field including a signal to initiate antenna selection and (ii) a number N indicative of a number of sounding packets which follow the at least one packet including the HT control field and which are to be used for antenna selection;
• an estimating unit configured to estimate a channel matrix based on a characteristic of the channel as indicated by the received N sounding packets;
• and
• a selecting unit configured to select a subset of antennas according to the channel matrix, wherein the receiver is further configured to receive a non-ZLF+HTC control packet immediately followed by plural consecutive zero length frame (ZLF) sounding packets, the non-ZLF+HTC packet having an antenna selection control (ASC) field including a receive antenna selection sounding indication (RXASSI) signal to initiate antenna selection and a number N of the plural consecutive ZLF sounding packets.