To meet the development needs of the ultra-wide bandwidth low-frequency pulsar receiving system for the Qitai Radio Telescope (QTT), Senior Engineer ZHANG Hailong from the Xinjiang Astronomical Observatory (XAO) of the Chinese Academy of Sciences (CAS), along with his doctoral student ZHANG Yazhou, developed a coherent de-dispersion digital backend system on a polyphase filter channelization algorithm. The system is built on their self-developed Field-Programmable Gate Array (FPGA) signal processing platform.

Related results were published in the Astronomical Journal .

This system achieves ultra-wide bandwidth signal sampling, channelization, firmware algorithms for parallel transmission of multiple signals, real-time coherent de-dispersion processing of ultra-wide bandwidth multi-channel pulsar signals, and scientific data packaging.

Using the L-band (964–1732 MHz) receiving system of the NanShan 26-meter Radio Telescope, the researchers systematically tested their digital backend system and obtained high-quality observational data. By processing this data with the professional pulsar data processing software DSPSR, they achieved high signal-to-noise ratio pulse profiles, validating the effectiveness of the digital backend system.

“Compared with related research published both domestically and internationally, the ultra-wide bandwidth low-frequency pulsar coherent de-dispersion digital backend prototype system developed by XAO has reached an internationally advanced level.” said ZHANG Hailong.  

Design of the QTT ultra-wide bandwidth low-frequency pulsar coherent de-dispersion digital backend prototype system

Channelization scheme for QTT ultra-wide bandwidth low-frequency pulsar signals

Measured Results of the QTT Ultra-wide bandwidth Low-frequency Pulsar Coherent De-dispersion Digital Terminal (Dynamic Spectrum of Subband J0332+5434)