Fast-converging conjugate-gradient adaptive algorithm for complex channel estimation

An efficient adaptive digital filtering algorithm called complex block conjugate least mean square (CBC-LMS) is presented for complex wireless channel estimation. The proposed technique incorporates the conjugate gradient principle into the complex block LMS algorithm. In addition, the novel algorithm generates a unique optimal stepsize along each conjugate direction at each iteration. Computer simulations show that the proposed CBC-LMS yields better performance than existing complex block LMS algorithms, while maintaining computational efficiency.