On the Determination of C/A Code Self-Interference with Application to RFC Analysis and Pseudolite Systems

A GNSS receiver operates by acquiring and tracking signals from multiple satellites in view. In general, multiple signals, possibly from multiple systems, occupy the same bandwidth and, hence, interfere with one another. The Spectral Separation Coefficient (SSC) is a metric that is commonly used to assess such interference. The SSC is computed between a pair of signals, the victim (or desired signal) and the interferer, and can be thought of as a measure of the average fraction of the interfering signal’s power which passes through the victim signal correlator. Typically, a single SSC value is computed for each pair of signal types. However, it has long been known that for some signals the SSC is strongly dependent on the (Doppler) frequency difference between each pair of signals. The self-SSC of the GPS C/A signals exhibits particularly strong frequency dependency. In recent years a number of simulation based approaches have been proposed to determine a suitable single SSC value to be used in this case that accounts for this frequency dependency. In this paper, a novel, computationally efficient technique called SSC Factorisation is proposed to this end. This technique is then applied to the fields of radio frequency compatibility studies and pseudolite systems. The proposed technique can be readily extended to signals other than the GPS C/A code.

O'DRISCOLL Cillian;  FORTUNY GUASCH Joaquim; 

2013-05-30

Institute of Navigation

JRC79042

https://publications.jrc.ec.europa.eu/repository/handle/JRC79042,