A Short-Delay Multipath Mitigation Algorithm Based on Variable Step-Size LMS Adaptive Filtering

The multipath in the inter-spacecraft microwave ranging system is the short-delay multipath generally. The performance of existing multipath mitigation algorithms degrade in the short-delay scenario, and therefore an adaptive filtering algorithm based on variable step-size LMS is exploited for estimating the parameters of multipath signals. Firstly, the equation of variable step-size LMS is deduced. Then, the signals parameters are estimated recursively though the adaptive filtering algorithm. Multipath elimination is performed by substracting the estimated multipath effects from the measured correlation function. Simulation results validate that the proposed method is superior to the existing algorithms in the aspect of convergence rate and ranging accuracy for the short delay multipath. Therefore, it is a viable solution for achieving high accuracies measurements in microwave ranging system with short-delay multipath.