Fast and efficient proportionate adaptive algorithms for pure delay estimation

Pure delay estimator is a vital component in network echo cancellation systems targeting sparse echo paths with unknown pure delays. In this paper, the Proportionate Normalized Least Mean Square (PNLMS) algorithm is applied to a sub-rate pure delay estimator. Compared with the Normalized Least Mean Square (NLMS) algorithm [1], the PNLMS algorithm can detect the pure delay faster but the increased computational complexity is high. To make the overall system more efficient for implementing on DSP platforms, two novel simplified proportionate adaptive algorithms are proposed. The simulation results demonstrate that the proposed algorithms offer comparable performance of pure delay estimation as the PNLMS algorithm with much less computational complexity.