An LMS-based decision feedback equalizer for digital cellular radio

In a TDMA mobile communication system, the equalizer is a common device to compensate the intersymbol interference caused by the multipath effect. In this paper, we consider the decision feedback equalizer (DFE) for application to the North American IS-54 systems. Due to the fast fading characteristic of channels, most conventional DFEs use the recursive least square (RLS) algorithm. However, it is known that the RLS algorithm is computationally intensive and not easy to implement. In this paper, we employ the ideas of multiple-training and multiple-tracking to propose an LMS-based equalization scheme. We also incorporate the coded digital verification color code (CDVCC) of the TDMA slot as an additional training sequence. Simulation results show that the new scheme can achieve a bit error rate of 3% at the mobile speed of 80 km/hr and still have low complexity.