A Novel Echo Cancellation Algorithm and Architecture Based on Multi-path Adaptive Interpolated Fir Filter

In this paper, a new multi-path adaptive interpolated FIR (AIFIR)-based echo canceller is presented to perform the echo cancellation in full-duplex digital transmission over digital subscriber loop (DSL). This new approach inherits the concept of conventional AIFIR-based echo canceller, where the long tail portion is modeled by an adaptive sparse FIR filter. We then propose a multi-path structure to break the inherent design tradeoffs in the conventional AIFIR-based echo canceller; that is, we employ more than one AIFIR filters to model the corresponding tail portions of echo path. In addition, an efficient implementation of the Image-Suppression Filter (ISF) is suggested to reduce the complexity in performing the function of multi-ISFs. Finally, we apply the proposed scheme to the design of echo canceller in a Single-pair High-speed Digital Subscriber Loop (SHDSL) transceiver. Computer simulations show that the flexible multi-path AIFIR-based echo canceller can reduce up to 20% computational complexities compared with previous works. About 60% complexity savings are obtained compared with the direct transversal implementation of echo canceller. The complexity savings result in efficient VLSI implementation of the echo canceller in DSL applications.