Systolic implementation of windowed recursive LS estimation

A dual-state systolic structure is proposed for performing joint up- and downdating operations encountered in windowed recursive least-squares estimation problems. It is derived by successively performing Givens rotation for updating and hyperbolic rotation for downdating. Due to the data independency, a series of Givens and hyperbolic rotations can be interleaved and parallel processing can be achieved by alternatively performing updating and downdating both in time and space. By using Cordic cells, both hardware complexity and throughput rate performance can be improved.<>