Efficient echo cancellation in single carrier duplex satellite systems

Abstract

Modern satellite communication systems use special bandwidth optimization techniques to organize full-duplex link on single carrier frequency and this way to reduce occupied bandwidth and transmitted power. These techniques require robust echo cancellation mechanism to subtract the delayed own signal from satellite composite signal on earth stations and to track the echo path online.A comparative analysis of adaptive filters algorithms robustness is being performed. Based on the results of the analysis, the efficient configuration of echo canceller is proposed. The echo canceller is based on specially designed for robust-critical applications algorithm (so-called correlation algorithm). The main advantages of this algorithm are low computational complexity and high robustness.The simulation results demonstrate the proposed echo canceller functional characteristics in comparison with echo cancellers based on such algorithms as: least mean square (LMS), normalized LMS, weighted recursive least square (RLS), frequency domain LMS and lattice RLS. In particular, the algorithm provides residual echo loss on 35 dB, acceptable transient response duration and low computational complexity at the same time. The functional characteristic of proposed echo canceller allows tracking of the echo path dynamics online and to realize it on cost-effective hardware platforms.