A dual mode decision feedback equalizer employing the conjugate gradient algorithm

Decision feedback equalizers are commonly employed to reduce the error caused by intersymbol interference. In this paper, we propose a decision feedback equalizer (DFE) that automatically switches between the constant modulus algorithm (CMA) and the decision-directed algorithm (DD). Performance is compared with a CMA-DFE. To improve the slow convergence characteristics of the LMS algorithm, the conjugate gradient (CG) algorithm is employed. Simulation results show that the proposed decision feedback equalizer provides better performance and faster convergence with reasonable computational complexity.