Blind Equalisation of High-Order QAM Channels Using a Fuzzy-Logic Tuned Constant Modulus Algorithm and Soft Decision-Directed Scheme
Sheng Chen, B.L. Luk, Chris J. Harris, Lajos Hanzo · ePrints Soton (University of Southampton) · 2009
We consider blind equalisation for high-order quadrature amplitude modulation channels using a lowcomplexity high-performance concurrent constant modulus algorithm (CMA) and soft decision-directed (SDD) scheme.Instead of using a constant step size, we design a fuzzy-logic (FL) tuning unit to adjust the step size of the CMA.Simulation investigation confirms that faster convergence can be achieved with this FL assisted CMA and SDD scheme, compared with the constant step-size CMA and SDD scheme.Specifically, the former requires several thousands fewer samples to converge to the same steadystate solution achieved by the latter.