Date Added: Jan 2011
Mobile users' quality of service is limited by the fading problem. In fading, within the duration of any given call, mobile users experience severe variations in signal attenuation. Solution to this problem is the use of some type of spatial diversity. Spatial diversity generally requires more than one antenna at the transmitter. However, many wireless devices are limited by size or hardware complexity to one antenna. When mobiles cannot support multiple antennas due to size or other constraints, conventional space-time coding cannot be used to provide uplink transmit diversity. In this paper, a new concept of cooperation diversity has been introduced; where mobiles achieve spatial transmit diversity on uplink channel by relaying each other's messages.