Research on Channelization Techniques of Radio Astronomical Wideband Signal with Oversampled Polyphase Filter Banks  

作　　者：Meng Zhang Hai-Long Zhang Ya-Zhou Zhang Jie Wang Shao-Cong Guo Qiao Meng 

机构地区：[1]Xinjiang Astronomical Observatory,Chinese Academy of Sciences,Urumqi 830011,China [2]University of Chinese Academy of Sciences,Beijing 100049,China [3]Key Laboratory of Radio Astronomy,Chinese Academy of Sciences,Nanjing 210008,China [4]National Astronomical Data Center,Beijing 100101,China [5]School of Information Science and Engineering,Southeast University,Nanjing 211100,China [6]School of Cyber Science and Engineering,Qufu Normal University,Qufu 273165,China

出　　处：《Research in Astronomy and Astrophysics》2023年第8期188-205,共18页天文和天体物理学研究（英文版）

基　　金：supported by the National Key R&D Program of China(Nos.2021YFC2203502 and 2022YFF0711502);the National Natural Science Foundation of China(NSFC,Nos.12173077 and 12003062);The Tianshan Innovation Team Plan of Xinjiang Uygur Autonomous Region(2022D14020);the Tianshan Talent Project of Xinjiang Uygur Autonomous Region(2022TSYCCX0095);the Scientific Instrument Developing Project of the Chinese Academy of Sciences,Grant No.PTYQ2022YZZD01;China National Astronomical Data Center(NADC);the Operation,Maintenance and Upgrading Fund for Astronomical Telescopes and Facility Instruments,budgeted from the Ministry of Finance of China(MOF);administrated by the Chinese Academy of Sciences(CAS);Natural Science Foundation of Xinjiang Uygur Autonomous Region(2022D01A360)。

摘　　要：Digital channelization decomposes a wideband signal into multiple adjacent sub-bands using Parallel Technology.Channelization can effectively reduce the pressure on the radio astronomy digital backends system and make wideband signal processing possible.Aiming at the problems of signal attenuation at sub-band edge,spectral leakage and aliasing encountered in wideband signal channelization,algorithms to reduce the problems are studied.We design a Critically Sampled Polyphase Filter Bank(CS-PFB)based on the Finite Impulse Response digital filter with a Hamming Window and systematically analyze the frequency response characteristics of the CS-PFB.Based on the channelized structure of the CS-PFB,an Over Sampled Polyphase Filter Bank(OS-PFB)is designed by data reuse,and the filtering frequency response characteristics of CS-PFB and OS-PFB are compared and analyzed.Using the wideband baseband data generated by the CASPSR(Collaboration for Astronomy Signal processing and electronics research Parkes Swinburne Recorder),we implement sub-band division and 16-band output of these data based on the 2×oversampling OS-PFB,and the problem of spectrum inversion in the sub-bands is corrected.After removing 25%of redundant data in the head and tail of each sub-band,we recombine the sub-bands into a wideband.The wideband signal is almost identical to the original observed signal.Therefore,the experimental results show that the OS-PFB can improve the channel response.For the 400 MHz baseband data of J0437-4715,we compare the pulse profile obtained from the original baseband data with the pulse profile obtained after the channelization and recombination.The phase and amplitude information of the pulse profiles are consistent,which verifies the correctness of our channelization algorithm.

关 键 词：(stars:)pulsars general-methods analytical-miscellaneous-methods data analysis 

分 类 号：P145.6[天文地球—天体物理] P161[天文地球—天文学]