Radio surveillance spectrum - Signal analysis and identification

Communications have become essential, both in the civilian sphere (the political, economic and social functioning of our society, which is increasingly based on the transmission of information between individuals, economic players, managers and regulatory bodies), and in the military sphere (the conduct of forces and control of the theater of operations).

The rational and efficient use of spectrum for civil applications, and the verification of the correct application of regulations, has always required signal analysis functionalities integrated into spectrum monitoring resources. The technical analysis of radiocommunications signals is mainly linked to the need to characterize and identify these signals, to make more reliable and precise control operations on the degree of spectrum occupation, the measurement of radio field levels and the estimation of modulation parameters, but also to diagnose interference situations.

In the military field, the need for forces to control the proper use of the spectrum for their own communications, as well as to detect and monitor opposing emissions, has always called for more or less automated functions for recognizing received signals and identifying intercepted transmitters, integrated into tactical devices deployed in theaters or intelligence systems. These functions are essential components of warning and self-protection systems for forces in theaters of operation. They are also one of the foundations of signals intelligence. Whenever possible, decoding signals and listening in on transmitted content are valuable complements to intelligence functions.

In recent decades, advances in digital technologies, the volumes transmitted, the variability of waveforms and radio access protocols have all increased dramatically, increasing the need for analysis :

• radioelectric environments have become dense and fluctuating ;

• increasingly broadband, heterogeneous and unsteady signals;

• massively parallelized processing of raw data extracted from the radio interface ;

• Increasing automation.

This presentation builds on previous articles [TE 6 890] and