Frequency-shift determination

A receiving apparatus (7) that can estimate a motion-induced frequency shift in a received signal comprises a processing system (205) and a receiver (204) configured to receive a signal comprising one or more instances of a transmitted signal. The processing system (205) is configured to generate data representative of a plurality of impulse response functions by deconvolving the received signal with each of a plurality of templates representative of the transmitted signal shifted in frequency by a different respective frequency shift. The processing system (205) is further configured to evaluate a signal-to-noise measure for each of the plurality of impulse response functions, and to identify an impulse response function of the plurality of impulse response functions for which the signal-to-noise measure satisfies a peak criterion.