A fast Fourier transform (FFT) based sonar signal processor

The design for a convolution processor is presented, which employs a single highly parallel implementation of the FFT algorithm. This processor is eminently suited for real-time matched filtering of linear FM (LFM) signals encountered in sonar systems. Computer simulations have shown that this processor, which uses fixed point arithmetic and modest word sizes can efficiently handle signals with multiple targets and relatively large doppler shifts. The parallel architecture provides a throughput rate sufficient for computing both forward and inverse transforms in the one processor. This retains for the system the flexibility for frequency domain adaptive beamforming, attractive in many sonar applications.