A Pipelined Adaptive Lattice Filter Architecture

Abstract

In this chapter, we employ the relaxed look-ahead to design new concurrent stochastic gradient lattice adaptive algorithms [Hon84], which are inherently pipelined. The adaptive lattice filters designed using relaxed look-ahead have the property that the hardware requirements for these filters are independent of the speed-up or the level of pipelining. The proposed adaptive lattice algorithms are then employed to develop a pipelined adaptive pulse-codemodulation (ADPCM) codec for image compression applications. Preliminary results on the performance of the pipelined ADPCM codec were found to be very promising [Sha92b]. As expected, the hardware requirements for the new ADPCM codec was found to be independent of the number of quantizer levels L the order of the predictorNand the speed-up M. This is an improvement over [Par91d], where the conventional look-ahead technique [Par89b] was employed to pipeline the ADPCM.