October 2, 2017

Detecting and monitoring inter-modulation products during spectrum reallocation

Stations might face unexpected problems related to inter-modulation interference during frequency repack.

Avateq Corp. has been vocal about signal interference and the problems it brings. In order to address the issue, we've made signal interference detection as a standard feature in all Avateq's RF layer monitoring receivers and signal analyzers.

The latest model of AVQ1022 - RF Layer Monitoring Receiver and Signal Analyzer can be used not only for detecting the interference of different nature - CCI, ACI or inter-modulation - during frequency planning and re-packing, but also for constant day-by-day, 24-7 monitoring the in-band of useful signal during transmitter system's normal operations. Caused by inter-modulation products (including third and fifth harmonic), in-band interference can be identified by its "distant" source - usually not an adjacent channel signal. AVQ1022 calculates and plots the interference power spectral density (PSD). In majority of real-world applications, the PSD shape can assist in identification of the interference nature.

Examples of AVQ1022 screenshots with different types of interference:

Clean signal
Adjacent Channel Interference (ACI)


In-band Interference