Adaptive blind equalization for Rayleigh fading ionospheric channels
Sun Shouyu · Chinese Journal of Radio Science · 2003
The constant modulus blind equalization technique is investigated over a slow Rayleigh fading ionospheric channels with additive white Gaussian noise. The well-known constant modulus algorithm (CMA) is a very important approach for blind channel equalization. However, the standard constant modulus algorithm has some disadvantages such as the slow speed of convergence and phase rotation. In the paper, a modified constant modulus algorithm (MCMA) is proposed. The proposed algorithm minimizes a modified error function and the learning-rate is multiplied by received sequences. Through a performance comparison for 8-PSK signal constellations,the simulation results demonstrate that the MCMA leads to faster convergence and smaller intersymbol interference (ISI) in steady-state than those obtained using the CMA. In addition, the equalizer output has neither the phase rotation nor the delay.