Real time implementation of multidimensional fast Fourier transforms

The real-time implementation of multidimensional fast Fourier transforms using a high-speed fast Fourier transform FFT chip set is presented. The chip is capable of performing 1024-point complex FFTs in 26 μs and 64 K-point complex FFTs in 1.64 ms. The chip set comprises the digital array signal processor (DASP) and the programmable array controller (PAC). The DASP performs the arithmetic operations while the PAC performs all of the control functions, including address generation. The chip set provides a better solution for performing high-speed FFT operations than standard digital signal processing (DSP) chips or array processors, since the PAC functions also help alleviate input/output bottleneck problems. It is shown how the DASP can be used to perform 2-D FFTs. Radar imaging, using synthetic aperture radar (SAR) is a good example of a process requiring high-speed 2-D FFT operations for real-time realization. High-speed 3-D FFTs are often employed in medical imaging applications such as magnetic resonance imaging (MRI). The primary focus is on radar imaging as an application example, but the results could very easily be extended to the medical imaging application