Jamming detection and SNR/SNJR estimation

For proper communication system design and operation, system engineers want to make sure that the signal-to-noise ratio (SNR) and signal-to-noise-plus-jamming ratio (SNJR) are within sufficient design link margin. However, an over design to make the link margin too high is costly and is not desirable for operation. In order to choose a proper link margin, a proper estimate of SNJR becomes critical. In case the communication channel has dynamic situation that causes the SNJR to vary relatively quickly, a means to estimate the SNJR as a function of time becomes essential so that the system can adjust the SNJR accordingly through link budget adjustment. In this paper algorithms for jamming detection and SNJR estimation are described and their performances are given by simulation. Performances of jamming detection and SNJR estimation are obtained for the scenario of MPSK signal in the presence of Gaussian noise and partial-time Gaussian jammer. Multiple jammers are randomly distributed within the observation time. Simulation shows that the algorithms work very well and the standard deviation of SNJR estimation error is about 4%.