Radar processing gain improvement over frequency using the discrete wavelet transform

The range-gated fast Fourier transform (FFT) is the most common implementation of the optimum receiver for radar signals having random phase, frequency, and arrival time. In practice, the receiver is only optimum for input signals with frequency equal to an FFT bin frequency. Here the discrete wavelet transform (DWT) is applied to the FFT output to recover processing gain (PG) lost for nonoptimum input signals. Since the FFT and FFT-DWT have optimum performance for different input frequencies, these algorithms can be combined by binary integration (BI) to result in a dramatically improved worst case PG over frequency