DUAL DIVERSITY COMBINING AND EQUALIZATION IN DIGITAL CELLULAR MOBILE RADIO

The performance of dual diversity reception combined with equalization techniques in digital data transmission over frequence-selective fading channels is investigated. General results are applied to the mobile radio channel modeled by the sum of two delayed and independent Rayleigh-fading beams with additive Gaussian noise. For statistically independent diversity paths, we provide estimates of average attainable error rates and outage probabilities as functions of system parameters. The dependence among the important system parameters are exhibited graphically for several illustrative examples including quaternary phase-shift keying (QPSK). In the optimized uncoded QPSK with 1.5 b/s/Hz, two orders-of-magnitude in outage probability can be gained by diversity reception. When we compare the uncoded average probability of error for the optimized MSE systems, we find at most an order-of-magnitude difference among the different equalizers investigated except for the zero-forcing equalizer whose performance is drastically inferior to the others. Again, dual diversity can provide two orders of magnitude improvement in the average error rate or in outage probability for the uncoded optimized systems.