Space-time trellis coding with turbo equalisation for the EGPRS system

Transmit diversity techniques like delay diversity (DD) or space-time trellis coding (STTC) utilise several transmission antennas and thereby protect mobile radio systems against fast fading. The more complex STTC can recover bursts with a few errors, but on the other hand it increases bit errors for bad bursts. Therefore the concatenation of an outer convolutional code and STTC is not superior to the simple DD scheme. The outer coding is commonly used in mobile packet data applications to detect and correct transmission errors. We are interested in further improving STTC performance by the iterative turbo equalisation (TE) technique, which performs space-time decoding-equalisation and outer decoding in an iterative fashion. Our objective is to analyse whether TE can exploit the more complex STTC structure by comparing the iterative gains of STTC and DD. The performance evaluation is done by simulations in the Enhanced General Packet Radio System (EGPRS) platform.