Using two or more receiving antennas on a wireless device to eliminate multipath signal distortion. Typically, the signal from the antenna with the least noise (best SNR) is chosen, and the other antenna is ignored. However, there are also methods that use incoming signals from both antennas. It is quite common to see two antennas on 802.11 wireless LAN access points and PC cards. See
MIMO,
beamforming,
signal-to-noise ratio and
multipath.
Antenna Diversity for 802.11
Note the dual antennas on the 802.11b access point (top left) and PC card (bottom) from Alvarion. Antenna diversity is an important feature of the 802.11 specification. (Image courtesy of Alvarion Ltd.)