GPFFC: Wideband Signal Channelization Algorithm Using Parallelized GPU Technology

To meet the requirements of real-time processing of wideband or ultra-wideband signals from large aperture radio telescopes, we designed and implemented a Graphics Processing Unit-based parallel Polyphase Filter bank Fast Channelization algorithm, which we use to study the processes of the pulsar baseband data unpacking, channelization, and packing. Graphics Processing Unit channelization technology has been optimized. By using the Compute Unified Device Architecture multidimensional thread model, tasks are subdivided into multiple small blocks to improve parallel computing efficiency. The data processing was optimized based on Compute Unified Device Architecture asynchronous processing to reduce Graphics Processing Unit idle time, which improved the parallel computing efficiency, increasing the speed to approximately 1.4 times that of the non-optimized implementation. Baseband data for pulsar J0437-4715, recorded by the CASPER Parkes Swinburne Recorder backend of the Parkes 64-meter radio telescope, were used for testing. The pulsar baseband signal was subdivided into sub-bands, and the data from each was then packaged. Finally, the Digital Signal Processing Software for Pulsar Astronomy was used to process the baseband data of multiple sub-bands, and the pulse profiles of multiple sub-bands were merged into wideband pulses, which were consistent with the pulse profiles of the raw baseband data in phase and signal-to-noise ratio, verifying the effectiveness of the Graphics Processing Unit-based parallel Polyphase Filter bank Fast Channelization algorithm. It processes 400~MHz dual-polarized data in 5.8 s with 8-bit quantization over an 8~s observation time, meeting the real-time processing requirements of pulsar baseband data.