Real-Time Non-Uniform Fast Fourier Transform for Multibeam Digital Beamforming

Abstract

This paper describes the structure of a reconfigurable digital beamforming network, which offers significant improvements in implementation complexity and cost, while maintaining a high degree of flexibility. This architecture supports a multi-beam array antenna and allows complete flexibility in steering each individual beam produced by this antenna, achieving computational complexity comparable to that of the Fast Fourier Transform as the number of beams and antenna elements change. The proposed architecture is built upon the theory behind the Non-Uniform Fast Fourier Transform and is demonstrated for linear array geometries with regular or non-regular element positions. Fixed-point simulations, with a view to real-time hardware implementation, demonstrate effective reduction in the computational complexity of the reconfigurable digital beamforming network and its full flexibility.