Real-time high-resolution radio frequency channel sounder based on the sliding correlation principle

A channel sounder based on the cross-correlation properties of pseudo-noise random sequences, known as swept time delayed cross-correlation channel sounder, is presented. This sounder enables the characterisation of doubly selective channels, providing both amplitude and Doppler spectra information. It performs real-time measurements of specific radio channels with a high resolution of 2 ns for adjacent multipath component, and a current maximum Doppler spread of ±100 Hz, but that can go beyond ±1 kHz, if some components are upgraded. The amplitude measurements given by the sounder, presented as power delay profiles, have a dynamic range of about 35-40 dB. This study provides detailed information on the most relevant components used to develop the sounder, and presents some of the calibration measurements performed on the bench, as well as specific radio frequency measurements at 18.7 and 60 GHz in a controlled environment. Finally, improvements that are feasible to be implemented in the near future are proposed.