Date Added: Dec 2009
Multiple antennas for transmitting and/or receiving data effectively mitigate fading. Obtaining the benefits of multiple transmit antennas may however require the use of special space-time signaling schemes such as Orthogonal Space-Time Block Codes (OSTBCs), a class of easily decoded space-time codes that achieve the full diversity order. The family of OSTBCs simplifies maximum-likelihood decoding by decoupling the vector detection problem into a set of scalar detection problems. A major limiting factor in the deployment of MIMO systems is the cost of multiple radio frequency chains (such as amplifiers, mixers and analog-to-digital converters) at both ends of a wireless link. A powerful solution is to select a subset of the available antennas while keeping the advantages of using all antennas.