Abstract: Aiming at the problems of slow convergence speed and heavy computation of traditional convex combinatorial affine projection sign algorithm, a fast convex combinatorial affine projection sign algorithm based on S-type function is proposed. The algorithm uses a new S-type function to replace the sigmoidfunction in the traditional algorithm. It also, improves the iterative formula of joint parameters, avoids complex exponential operation and reduces the amount of calculation. Meanwhile, the instantaneous transfer scheme is adopted to make the convex combination algorithm accelerate the adaptation process of the small-step slow algorithm after the initial adaptation process or a sudden change, so as to improve the speed of the convex combination algorithm. Simulation results in the system identification and acoustic echo cancellation environment show that the algorithm has good mean square performance and tracking performance, and has faster convergence speed and lower computational complexity compared with the traditional convex combination affine projection sign algorithm.

Key words: adaptive filtering, affine projection sign algorithm, convex combination, S-type function