Citation
Abstract
A large number of microwave transmitters will be installed in large urban centers in the future to provide high-density fixed services (HDFS). The frequency band proposed for use by these transmitters overlaps the Ka-band (27-40 GHz) allocated for NASA’s Deep Space Network (DSN) receivers. Interference signals from these transmitters can propagate over the horizon and interfere with the DSN through various mechanisms, such as ducting, rain scattering, and diffraction. In this article, we have used the available International Telecommunication Union (ITU) models and a Monte Carlo simulation to estimate the aggregate interference power from the HDFS transmitters in the Los Angeles area as received by a DSN station located at Goldstone, California. It was found that, for a worst-case scenario, when a single transmitter main beam points to the DSN antenna and the separation distance is less than 200 km, the threshold for protecting the DSN receiver at Ka-band will be exceeded. An urban area such as Los Angeles has been assumed to have 3000 HDFS transmitters spreading with various maximum radial distances. Our simulation shows that the distributed effective isotropic radiated power (EIRP) of multiple HDFS sites will produce higher interference power at Goldstone as compared with an equivalent single transmitter with a normally distributed EIRP. When the HDFS spatial distribution has a maximum radial distance of 50 km, the received interference power at Goldstone exceeds the DSN threshold. The aggregate power and antenna gain increase with increasing transmitter numbers and distributed radial distances. This article provides solid results for consideration by the ITU and the HDFS community, and presents possible interference-mitigating approaches for the future HDFS deployment.
Keywords
Details
- Volume
- 42-138
- Published
- August 15, 1999
- Pages
- 1–18
- File Size
- 776.7 KB