A FFT-based partial matched filter (PMF)

acquisition threshold setting method for fast GPS acquisition is

presented. Normal distribution and numerical fitting technique

instead of real decision variable (DV) distribution are used in

derivation to approximate the threshold expression, and the

modification method for the threshold expression is also

presented. The threshold expression is based on the individual

FFT Doppler bin false alarm probability rather than the

convention whole detector false alarm probability. The

proposed threshold expression can be adjusted according to

the false alarm probability, the noncoherent accumulation

(NCA) length and the estimated noise variance. Furthermore

we discuss the implementation of zero-padding FFT with its

advantage and limitation. The performance is superior

compared to the reference method in terms of signal-to-noise

ratio (SNR) when detection and false alarm probabilities are

used as measurement criteria.