An apparatus and method allow receivers to quickly acquire a pseudorandom
noise signal. A receiver advantageously detects frequency shifts using a
compact parallel process hardware implementation of a Discrete Fourier
Transform (DFT). The simultaneous detection of multiple frequencies allows
the receiver to search the frequency range of the transmitted signal in
larger increments of frequency, thereby increasing the speed of
acquisition. One receiver does not use coherent integration before
computation of the transform and advantageously maintains a flat frequency
response. The flat frequency response of the DFT circuit enables searching
of multiple frequency offsets without CPU intensive processing to
compensate for frequency response variations. A receiver can include a
Doppler correction circuit, which permits correlation data with frequency
shift in the code to be non-coherently integrated among relatively fewer
addresses or tap positions in memory.