Research And Application Of Digital Channelization Structure Optimization Method

In the increasingly complex electromagnetic environment of modern war,the reconnaissance receiver needs many capabilities to play its role,such as wide band coverage,frequency resolution,high sensitivity,real-time signal reception and large dynamic range.With the continuous progress of digital signal processing technology and electronic technology,broadband digital channelized receiver emerges as the times require.Because the channelized signal has a direct impact on the subsequent signal sorting and direction finding,the research and implementation of Wideband Digital Channelization technology is of great significance.The rapid development of digital signal processing technology promotes the research of the narrow transition band filter banks in Digital Channelization.In order to solve the problem of high complexity in the design of narrow transition band filter banks in digital channelized receivers,this paper uses Frequency Response Masking(FRM)to optimize the prototype filter,and proposes a digital channelized structure and its design method based on frm.In this method,two prototype filters are interpolated by 32 times,and then the masking filter is used to filter the image brought by interpolation.Finally,the two masking branches are added to get the composite filter,and the decimation module is advanced,so as to reduce the sampling rate of channelized receiver and reduce the computational complexity of the design structure.Compared with the traditional low-pass filter banks and polyphase filter banks,the proposed structure can save 96.98% and 52.11% resources respectively.In order to improve the reconstruction performance of channelized receiver,the signal is reconstructed by analyzing and synthesizing filter banks.Aiming at the problem of signal cross channel in Digital Channelization structure,Fast Filter Bank(FFB)technology is introduced to optimize the structure.The reconstruction structures based on Analysis Fast Filter Bank(AFFB)and Synthesis Fast Filter Bank(SFFB)are proposed.The half band filter is used to design the prototype filter of this structure.By interpolating the filters at all levels,the effect of cross channel signal reconstruction is achieved,and the problem that the order of narrow transition band filter bank is too high is solved.Finally,through the computer simulation results and the complexity analysis of each structure,we can see that the complexity of the Digital Channelization structure design method based on FFB is lower.Finally,the design process and software implementation scheme of the channelized receiver are given.Through the performance test and analysis of the receiver,the correctness and reliability of the designed system are verified.