PERFORMANCE COMPARISON OF SPACE DIVERSITY AND EQUALIZATION TECHNIQUESFOR INDOOR RADIO SYSTEMS

In this paper, by means of analytical and numerical methods, we derive the bit error rate (BER) of pi/4-DQPSK systems in frequency-selective fading channels. For a theoretical analysis of the system, a simplifi ed two-ray channel model has been used, However, both Rayleigh and log normal distributions for the ray envelope have been considered, The sy stem performance, in the presence of antenna diversity and in combinat ion with a new nonlinear equalizer has been evaluated, In particular, it is seen that in hat fading environments, space diversity may improv e performance by more than 10 dB at BER = 10(-3) However, for channels with a large delay spread, nonlinear intersymbol interference (ISI) i s the predominant disturbance, and performance can only be enhanced by the nonlinear equalizer.