Time Domain Broadband Digital Beamforming Technology Research

Radar reconnaissance can get the signal parameter which contains the enemy’s information, by receiving、analyzing and processing the space signals. These obtained parameters can provide our own combat systems with the messages of interference and anti-interference, reconnaissance and counter-reconnaissance, sabotage and anti-sabotage. Since space signals are mostly wideband signals, such as the bandwidths of the sea’s or airspace’s background noise are huge, and wideband signal is carrying a large amount of information, being low correlation and low probability of intercepted and cracked, so the modern array signal processing mostly use broadband signals. Broadband DBF(Digital Beam Forming) is currently a active direction in the array signal processing aspects, the receiver can effectively obtain the information on the interested spatial orientation by beamforming.This paper will analyze and compare some broadband DBF algorithms, focuses on the time-domain method, then studies to optimize from the ways of algorithms and hardware. This paper firstly introduces a basic implementation of digital channel technology, then analysis the solutions for getting improvements by using FFT(Fast Fourier Transform) and STFT(Short Time Fourier Transform) method, and improves the effectiveness of these methods with some simulations. It can provide broadband DBF with prior information through digital channels technology. Secondly this paper introduces the principle of time-domain method from the broadband DBF frequency domain implementations. Focused on improving time-domain algorithm with space re-sampling technology and optimized filter design method. Finally, introduce the fractional filter and the improved methods to simplify the numbers of filter’s delay units and the phase shifters in hardware, to achieve the optimal broadband DBF time-domain implementation on algorithms and hardware design.