US Patent 7738598 Detection and time-of-arrival estimation using an IFM receiver

An instantaneous frequency measurement (IFM) receiver includes a receiver module for determining a frequency fe of a received signal. Also included is a discrete Fourier transform (DFT) module configured to sum values of digital samples of data in a block of data, wherein the values of the digital samples of data are based on the frequency fe. A confirmation module confirms the frequency fe, if the sum has a value greater than a predetermined threshold. The DFT module is configured to obtain the sum of N-sample points of data which are disposed in the block of data by using a DFT kernel function.