Benefits of coherent receiver antenna diversity in DCS 1800 full rate speech transmission

The deterioration of the error performance in mobile radio, such as the pan-European personal communications network (PCN) termed Digital Cellular System (DCS) 1800, due to time variant multipath propagation can be reduced by using diversity techniques. The application of coherent receiver antenna diversity (CRAD) is especially attractive because the parameters of an established mobile radio system remain unchanged. In this communication, the benefits of CRAD in DCS 1800 full rate speech transmission are considered. In order to fully exploit the benefits of CRAD, a soft output Viterbi detector with CRAD (CRAD-SOVD) tailored to predetection maximal-ratio combining (MRC) is applied at the receiver. Both the uncoded and coded bit error rate as well as frame error rate performance determined in extensive simulations of typical urban environments are presented. It is demonstrated that considerable signal-to-noise ratio improvements of ≈6.3 dB@BER=10^-2 at the output of the CRAD-SOVD, ≈5.5 dB@BER=10^-3 at the output of the convolutional decoder, ≈4.7 dB@FER=10^-2 at the output of the convolutional decoder, and ≈4.8 dB@FER=10^-2 at the output of the block decoder are obtainable by using two receiver antennas. These signal-to-noise ratio improvements are especially important with respect to close proximity operation in a multioperator environment which is likely to be established in DCS 1800