Make use of a number of receive antennas that are well separated (coherence distance) to generate independent receptions of the transmitted signal. Selection diversity: choose received signal with largest received power, S/N, etc. Switched diversity: choose alternate antenna if signal falls below a certain threshold.

Linear combining: linearly combine a weighted replica of all received signals. There is a worthwhile improvement even with two branch selection diversity. Performance improves with the number of diversity branches but the complexity increases sharply.

Selection and Switched Diversity: These are pretty straightforward systems

Receive Diversity Wimax

Space Time Coding – STC Space-Time Diversity Coding.Codes, interleaves and distributes the same symbol over

multiple antennas . Spatial Multiplexing Codes, interleaves and distributes different symbols over multiple antennas. For both, antennas transmit on co-channels

Space-Time Diversity Coding

Using Space-Time Diversity Coding in a multi-path environment increases Rx signal strength, increasing distance.

Space-Time Diversity Coding

Distributing the same data over co-channels on spatially displaced antennas, provides a temporally displaced set of sub-streams to be seen by the receiver.