Accurate frequency estimation using an all-pole filter with mostly zero coefficients

An all-pole Lth order filter with only M (M < L) nonzero coefficients is used to estimate accurately the frequencies of M closely spaced sinusoidal signals in noise. The method eliminates redundancy in the linear prediction equations which caused the spurious spectral peaks observed in previously known methods [3], [4]. Since most filter coefficients are zero, the computational effort required is small.