Methods and apparatus are disclosed for Automated Meter Reading (AMR) systems for determining quantities of a consumed utility product including electric, gas, and water service, using wireless data transfer. To compensate for the frequency drifts of the transmitters, these methods and apparatus, with minimum pre-processing of the received data, allow for on-the-fly adjustability of receiver bandwidth by merely changing a pre-calculated weighting function. As such, it is possible to use a fixed size Discrete Fourier Transform (DFT), or in particular a fixed N-point Fast Fourier Transform, for signals of different bandwidths.