Measuring scattering function of HF NVIS channel by sounding with the use of a noise-like BPSK signal

Abstract

Measuring parameters of the scattering function of near vertical incidence skywave (NVIS) radio links employed for data transmission is topical and fosters better understanding signal propagation as well as developing state-of-the-art cognitive radio systems. In this regard, the paper presents the findings of the research into the application of a noise-like phase-shift keying (PSK) signal for vertical sounding of NVIS radio links. There are presented the developed algorithms for processing the PSK signal to measure the scattering function and its parameters (signal-to-noise ratio, delay spread and Doppler spread) for multiple communication channels in the high frequency (HF) band. To carry out experiments on measuring scattering function of radio channels with bandwidth of 24 kHz and different mid-band frequencies, we employed developed ionosonde based on the universal software radio peripherals (USRP) platform.