Coding and optimum baseband combining for wideband TDMA indoor wireless channels

Optimum baseband combining with coherent BPSK (binary phase-shift keying) or QPSK (quadrature phase-shift keying) is an attractive technique for wideband TDMA (time-division multiple-access) portable communication radio links in view of its ability not only to combat dispersive fading but also to cancel cochannel interference. The performance of such a scheme is investigated for data rates ranging from 1 to 20 Mb/s. It is shown that convolutional coding with soft-decision Viterbi decoding can be a viable alternative to increasing the space diversity order even in the absence of interleaving if the effective diversity order is sufficiently large. The radio link performance is evaluated for various combinations of transceiver and channel parameters. The cochannel interference level and the space diversity order are shown to affect the data rate beyond which QPSK is preferable to BPSK