A NEW ADAPTIVE STEP SIZE MCMA BLIND EQUALIZER ALGORITHM BASED ON ABSOULATE ERROE AND ITERATION NUMBER
Thamer M. Jamel, Mohammed Abed Shabeeb · 2013
Blind equalization is a technique for adaptive equalization of a communication channel without the aid of the usual training sequence. The Modified Constant Modulus Algorithm (MCMA) is one of adaptive blind equalization algorithms. The drawbacks of the fixed step size of (MCMA) are slow convergence speed and high misadjustment. In order to overcome the tradeoff between fast convergence rate and low level of misadjustment of MCMA algorithm, we propose an enhanced technique based on an absolute difference error and iteration number to adjust a step size. The new proposed algorithm is called Combined Iteration and Absolute Error MCMA (CIAE-MCMA). Then we applied it for 16 QAM and 64 QAM adaptive blind equalizer systems. Simulation of adaptive blind equalizer with a typical telephone channel is evaluated to compare the performance of the proposed algorithm with MCMA and other two variable step size MCMA (VSS- MCMA) algorithms. It is observed from the simulation results, that the proposed algorithm has better performance compared with other algorithms in terms of fast convergence rate, low level of misadjustment and small BER.