Patent ID: 7680266

Claim:
A system for adaptive reduced-rank parameter estimation using an adaptive decimation and interpolation scheme comprising: (a) a first finite impulse response (FIR) interpolator filter with N I weights at the front-end of the system, represented by the N I ×1 parameter vector v(i)=[v 0 (i) . . . v NI (i) ] T that filters the input discrete-time signal r(i) with dimension M×1 and results in the interpolated received vector r I (i) with dimension M×1; (b) an adaptive decimation unit that has B parallel branches with appropriate decimation patterns represented by the M/L×M matrix D b that is responsible for the dimensionally reduction of the M×1 interpolated received vector r I (i), resulting in B reduced-rank decimated vectors r b (i) with dimension M/L×1; (c) a signal selection scheme that chooses the decimation pattern D b that minimizes the squared norm of the error signal defined by e b (i)=d(i)−w H (i) r b (i), where d(i) is a reference signal, the selection scheme utilizes the corresponding M/L×1 vector r b (i) that yields the minimum |e b (i)| 2 r(i) for the remaining signal processing; and (d) a second FIR filter with M/L weights, denoted reduced-rank filter w(i)=[w 0 (i) . . . w M/L (i) ] T , that is responsible for the estimation of the desired signal, the system computes the inner product of w(i) with r(i) in order to yield the parameter estimation for time instant (i) given by d est (i)=w H (i)r(i).