Processing signals of passive chirp ionosonde in the problem of estimation the HF channel availability

Abstract

The problem of increasing the efficiency of data transmission through a HF radio channel in the case of using passive sounding was studied. The paper presents the main characteristics of the stochastic radio channel with scattering (delay spread, Doppler spread and the signal-to-noise ratio) and communication modem, which have an impact on the efficiency of a communication system. Algorithm for estimating the channel characteristics using passive sounding was developed. Besides, the algorithms aimed at estimating the gain in emitted power and data transfer rate when adapting the communication system to the channel conditions were developed. It was experimentally found that for the mid-latitude radio paths, the power gain is 4.5 … 12 dB, and the gain in data transfer rate increases up to twice.