A target modulation is detected in a signal, e.g., a radio signal received
by a device such as a mobile communications terminal. Respective target
modulation correlations for respective carrier timing hypotheses are
determined by demodulating signal values corresponding to the signal for
the respective carrier timing hypotheses using a common carrier
demodulation template and detecting the target modulation from the target
modulation correlations. The target modulation may be, for example, a
pseudonoise (PN) code, such as a GPS code or a CDMA communications system
code, and the carrier timing hypotheses may correspond to various
potential Doppler shifts.