Presentation Information
[B-4-39]A Case Study on Receiver Desensitization of a Satellite Communication Terminal near Mobile Base Stations and Mitigation Based on Equivalent Source Estimation
◎Kyohei TOMITA1 (1. Japan Broadcasting Corporation)
Keywords:
Receiver desensitization,Blocking,Electromagnetic interference,Equivalent-source estimation,Method of moments,Satellite communication terminal
Satellite communication terminals play a critical role in disaster prevention and public safety when terrestrial networks are damaged, congested, or unavailable. However, rooftop installations may place them near mobile base stations, BWA stations, and other radio systems. In such environments, receiver front-end desensitization (blocking) caused by nearby high-power signals must be considered in addition to direct in-band interference. This paper reports a case in which an S-band satellite terminal for public safety became unavailable on a rooftop. Analysis of the frequency relationship between the terminal and the UQ WiMAX/BWA band confirmed that the receive band did not overlap the external signal band, indicating that the failure was not caused by in-band interference. Spectrum measurements, filter tests, transmission-condition tests, equivalent-source estimation, and method-of-moments analysis identified the cause as receiver desensitization due to nearby base-station signals. Relocating the terminal upward was insufficient, while adjusting the beam direction and tilt angle of the nearby base-station antenna reduced the electric field and restored voice communication.