Application of trellis coding to digital microwave radio

The authors examine the application of trellis coding to bandwidth-efficient digital microwave radio systems. Specifically, the authors study trellis codes carrying four information bits per transmitted symbol, as in uncoded-16 QAM (quadrature amplitude modulation), and codes carrying six information bits per symbol, as in uncoded-64 QAM. In addition to their performance at high SNRs (signal-to-noise ratios) the authors report their effective performance at threshold BER (bit error rate) values of 10/sup -4/ and 10/sup -3/ in a multipath fading environment, using the noiseless system signature and the equivalent CNR (carrier-to-noise ratio) degradation as performance measures.<>