Channel estimation in asynchronous multibeam satellite communications

This paper deals with channel estimation in asynchronous multibeam communications. That technique allows estimation of propagation delays, amplitudes and phases of the active users´ signals. An antenna array is considered at the receiver with a null steering beam former. After system model and beam forming mathematical presentation, the channel estimation method is developed. QPSK modulation is adopted with and FDMA physical resources sharing, under an AWGN environment. Evaluation of the proposed method is done with computer simulations. The obtained results show the good performance of this technique.