Optimum diversity combining and equalization in digital data transmission with applications to cellular mobile radio II. Numerical results

For Pt.I, see ibid., vol.40, no.5, p.885-94 (1992). The probability distributions of the data rates that can be supported by optimum receiver structures as well as the distribution of the Shannon capacity are studied. The dependences among the important system parameters are exhibited graphically for several illustrative examples including QPSK. At outage probabilities <10^-2 and at operating SNRs of 15-25 dB, the Shannon capacity with optimal dual diversity reception is about 2 bit/s/Hz higher than without diversity. Alternatively, at typical operations of QPSK with 1.5 bit/s/Hz, two orders of magnitude in outage probability can be gained by diversity reception. Comparing the uncoded average probability of error for the optimized MSE systems, at most an order-of-magnitude difference is found among the different equalizers investigated except for the zero-forcing equalizer, whose performance is drastically inferior. Dual diversity can provide two-orders-of-magnitude improvement in the average error rate or in outage probability for the uncoded optimized systems