Projection Filters for Data Analysis

This paper describes the use of moving narrow-band projection operators for finding precision complex demodulators for data analysis. These projection operators are made up of discrete Slepian sequences and replace the usual weighting procedures with coherent sidelobe cancellation to reduce out-of-band interference. A sliding block of length N gives N different estimates for each output sample. We use weighted averages, and variances, of the N available projections at each time step.