Modified constant modulus algorithm: blind equalization and carrier phase recovery algorithm

The modified constant modulus algorithm (MCMA) that accomplishes blind equalization and carrier phase recovery simultaneously is proposed. Since the constant modulus algorithm (CMA) converges independently of carrier recovery, at convergence an output constellation has a phase error. With modification of the CMA, the proposed algorithm can solve this problem. Furthermore, the new algorithm results in the performance enhancement of convergence speed and residual ISI compared to the CMA. In addition, the proposed algorithm achieves a performance as good as that of a joint CMA and decision-directed (DD) phase recovery scheme with reduction in computational complexity. Simulation results confirm the effectiveness of the proposed algorithm in removing ISI and correcting carrier phase error at the same time.