Application of Multiphase Filter Banks Technology in Low-Frequency All-Sky Total Power Measurement Experiments postprint

Abstract: As one of the important methods to detect the cosmic reionization epoch, the core goal of the low-frequency all-sky total power experiment is to detect the extremely weak neutral hydrogen 21 cm signal during the cosmic reionization period in the all-sky total power spectrum with a spectrum range of 50∼200 MHz. At present, the fast Fourier transform (FFT) is usually used to calculate the power spectrum, and the spectral leakage problem makes it impossible to completely deduct Radio Frequency Interference (RFI), which seriously interferes with the extraction of weak cosmic reionization signals. Polyphase filter banks (PFB) is a technique that evenly divides signals by frequency, which can replace FFT to calculate the power spectrum. In this paper, the basic principle of PFB and its implementation based on compute unified device architecture (CUDA) are introduced, and the performance of PFB and FFT is compared through simulation, and the performance differences of PFB of different orders are compared. Finally, the measured and experimental data are processed to verify the superiority of PFB technology, which provides an effective solution for the spectrum analysis of the all-sky total power experiment.