of a tower will often have two antennas; one is transmitting and receiving, while the other is a receive only antenna. Two receivers are used to perform diversity reception. The use of multiple antennas at both transmit and receive results in a multiple-input multiple-output (MIMO) system. The use of diversity techniques at both ends of the link is termed space–time coding. Antenna diversity for MIMO Diversity Coding is the spatial coding techniques for a MIMO system in wireless channels. Wireless channels severely suffer from fading phenomena, which causes unreliability in data decoding. Fundamentally, diversity coding sends multiple copies through multiple transmit antennas, so as to improve the reliability of the data reception. If one of them fails to receive, the others are used for data decoding. MIMO achieves spatial diversity and spatial multiplexing. See also Diversity schemes Space–time code Rake receiver Multiple-input multiple-output communications (MIMO) Distributed antenna system Macro diversity Diversity combining Transmit diversity Diversity gain Cooperative diversity References J. Moon and Y. Kim. “Antenna Diversity Strengthens Wireless LANs.” Communication Systems Design, pages 15–22, Jan 2003 S.M. Lindenmeier, L.M. Reiter, D.E. Barie and J.F. Hopf. “Antenna Diversity for Improving the BER in Mobile Digital Radio Reception Especially in Areas with Dense Foliage.” International ITG Conference on Antennas, , pages 45–48. Mar 30 2007. “Adaptive Arrays and Diversity Antenna Configurations for Handheld Wireless Communication Terminals” by Carl Dietrich, Jr. Feb 15, 2000. “Adaptive Antenna Tutorial: Spectral Efficiency and Spatial Processing” by Marc Goldburg. FCC Office of Engineering and Technology. Sept 7, 2001. “A MATLAB-based Object-Oriented Approach to Multipath Fading Channel Simulation” A white paper by C.D. Iskander. Feb 2008. Antennas Radio resource management Radio frequency propagation