Using adaptive equalizer to improve the performance of partial response syrstems

Abstract Signal distortion is inevitable in any communication system. In practice, equalizers are usually added to eliminate the distortion or intersymbol interference (ISI). Among various equalizers, adaptive equalizer is most attractive and is widely used in communication systems. If distorted condition changes as time progresses, the adaptive equalizer can adjust itself to minimize the distortion. Theoretical studies of the adaptive equalizer can be found in the literature while the actual implementation of the device is seldom mentioned. One purpose of this work is to implement an adaptive equalizer based on the theory reported in the literature. Furthermore, we apply this device to improve the performance of a class‐4 partial response system. The experimental data show that the performance with the help of the equalizer is very close to that predicted from theory. Experiments also show a satisfactory performance of the system using equalizer even if the channel is seriously distorted.