Distributed LMS estimation of scaled and delayed impulse responses

Abstract

The ability to perform distributed estimation across a neighborhood of nodes when the impulse responses present at each node are related by an unknown time delay and scaling is presented in this work. The time delay estimation is performed by correlating estimates of the unknown impulse response from neighboring nodes. The estimated time delay corresponds to the shift associated with the peak of this correlation. Next combination of neighboring nodes is performed by reweighting node estimates. This reweighting factor is calculated by forming the ratio of the norm of estimated impulse response in a reference node with the norm of the estimated impulse response in a neighboring node. Simulation results demonstrating improved convergence performance for a cooperative network when estimating the time delay and amplitude weights relative to the performance of a non-cooperative network are depicted.