Detection of Stbc Signal in Frequency Selective Fading Channels

Transmit diversity through two-transmit and one-receive antennas (DISO) with Alamouti’s Space-Time block coding (STBC) assumes the channel be flat and static over the coding block. Lindskog and Paulraj have extended this scheme for a time dispersive channel by doing the space-time coding over a large data block such as one burst. This helps to achieve diversity gain on a time-dispersive channel. However, there are two issues: 1) The receiver front-end consists of channel response filters and combining followed by a sequence detector. The channel filters on receive signal double the channel response size, consequently, increase the complexity of the sequence detector. 2) Channel needs to be static over the entire larger block of coded data as opposed to only two coded-symbol periods as per Alamouti’s scheme. This paper describes a new receiver that is based on MLSE with Euclidean metric for time-dispersive channel that provides joint STBC decoding and symbol detection. The proposed receiver assumes transmission with original STBC over two-symbol blocks to overcome the above restrictions and limitations. In addition, this paper tries to evaluate the impact on complexity compared to a one-transmit and one-receive (SISO) system. This proposed solution is more suitable for narrowband systems such as GSM/EDGE.