A New Type Of Decision Feedback Equalizer
Ahmad K. Aman, Steven A. Tretter · 2005
In digital communication, equalizers are often used to reduce the intersymbol interference of the transmission channel. This paper describes a decision directed feedback equalizer (DDFE) which consists of a channel estimator in the feedback section. The DDFE subtracts the ISI of the past symbols prior to equalization as opposed to the conventional DFE which subtracts the ISI of the past symbols after equalization. An improved version of the DDFE is introduced in this paper where the structure of the feedback section (channel estimator) is redesigned for better performance. The error-rate performance of the DDFE is compared to the error-rate performance of the conventional DFE. The error-rate curves indicate that as the ISI increases, the DDFE performs better than the conventional DFE.