Coherent Detection Method with Compensation at Transmitter in Time Division Duplex System

We proposed a pre-compensation method combining two wireless communication schemes, TDD(time division duplex) whose forward and reverse links use the same frequency, and the coherent detection as the best detection scheme to give a better mobile to base stations type communication system. The method is that the mobile station observes and estimates the channel characteristic from the received signal, and pre-compensates the transmitted signal adapting to the fading channel to improve the performance. Although preamble signals are necessary in the conventional method to observe and estimate the channel characteristic, the proposed method needs not the preamble signals, which decrease the information rate. Computer simulations show better BER performance than the differential detection that is usually used in Rayleigh fading channel.