Step tracking algorithm based on finite difference stochastic approximation for SATCOM on-the-move

In order to improve the tracking performance of SOTM, an improved step tracking algorithm based on finite difference stochastic approximation was proposed by employing the idea of parameter optimization after analyzing the system characteristics of SOTM. The main idea for this improved step tracking algorithm is to use finite difference to approximate the gradient which is near the optimal value for antenna beam adjusting, and adjust the antenna beam according to stochastic approximation. Only noisy measurements of the received signal strength were used in this process. The antenna beam can be steered to track the target satellite in azimuth plane and elevation plane in the direction of steepest ascent of received signal by using the novel step tracking algorithm. Computer simulation results show not only the effectiveness of the proposed algorithm, but also higher precision can be achieved by the proposed step tracking algorithm.