Adaptive DFE control with differential LMS algorithm

In order to implement high-speed, high-quality land-mobile digital communications, it is necessary to simultaneously satisfy both the trackability of the frequency-selectivity fading and the simplification of the algorithm. In this study, we propose the use of the differential LMS algorithm, which is applied to the decision feedback equalizer (DFE) as the adaptive algorithm. It can be expected that the introduction of the differential algorithm will make it possible to upgrade the tracking of propagation channels that can be approximated by the simplified Markov process. By using this algorithm, we designed an LMS-DFE having a simple configuration, and evaluation of the propagation characteristics by computer simulation has shown that, compared to the conventional LMS-DFE, it has better robustness to fluctuations and makes it possible to reduce the error floor by half. In addition, we also examined a diversity combined DFE and obtained similar results. (C) 2000 Scripta Technica, Electron Comm Jpn Pt 1, 84(1): 99-108, 2001.