1. An apparatus for confirming a frequency of a received signal comprising: a receiver for measuring a frequency, f e , of a received signal, a sampling module for sampling the received signal to form digital samples of data, a dividing module for partitioning the digital samples of data into blocks of data, a discrete Fourier transform (DFT) module configured to use a kernel function dependent on the frequency f e , the DFT module configured to sum the digital samples of data disposed in a block of data and provide a magnitude, and a confirmation module for confirming the frequency, f e , of the received signal, if the magnitude exceeds a predetermined threshold value; wherein the block of data is a first block of data, the magnitude is a first magnitude of data, and the predetermined threshold value is a first predetermined threshold value, the DFT module is configured to sum the digital samples of data disposed in a second and a third block of data following the first block of data and provide, respectively, a second magnitude and a third magnitude, and the confirmation module confirms the frequency f e , if the first magnitude exceeds the first predetermined threshold, and the second and third magnitudes each exceeds a second predetermined threshold.