An improved CMA-based hybrid algorithm for Blind channel equalization

Blind channel equalization has gained great impor- tance in the world of communications. Among a large num- ber of available blind equalization algorithms, the CMA (Constant Modulus Algorithm) enjoys widespread popularity because of its LMS-like complexity and robustness However, as the need for faster blind equalization of a variety of physi- cal channels (including mobile and wireless ones) increases, the search for more efficient and faster algorithms becomes paramount. This paper proposes one such hybrid CMA- based algorithm that exploits the advantages of the well- known concepts of signed-error update, pre-whitening and dithering. As such, it enjoys a simpler structure and faster convergence than other CMA-based algorithms, while retain- ing the robustness of the original CMA algorithm. The exten- sive simulation carried out here corroborates very well the claim that the proposed algorithm outperforms various exist- ing algorithms, including the DSE-CMA and PW-CMA. An attractive feature of the proposed hybrid algorithm is that it is particularly suited for channels where ill-convergence needs to be treated with minimum additional complexity and without any loss of robustness.