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Interference from the Robledo DSN Transmitters to Central Madrid IMT-2000/UMTS System through Terrain Diffraction at S-BandThis study evaluates the possible interference from DSN Robledo 70-m transmitter with Madrid IMT-2000/UMTS wireless users in Spain as both systems will share the same frequency band. Using the effective earth radius, the 50 km terrain profile between Robledo and Madrid is modified and reconstructed. The diffraction propagation losses due to mountain peaks are calculated for the receivers in Madrid urban area. The mountains along the path are simplified into a rounded knife-edge and a rounded obstacle. The results show that for a near surface receiver (1.5 m above the ground) in Madrid, interference signal powers received are less than -135 dBm, which is far below the -109 dBm, the IMT-2000 wireless phone threshold. When a receiver is located at about 40 m above the ground (e.g., the top of Clock Tower of Cibeles Palace), diffraction will generate interference power less than -115 dBm. We find that our calculation results are basically consistent with those from the Longley-Rice model, while the latter has smaller loss because of the low resolution terrain profile used. As a comparison, we also find that the measurements of interference powers of -121.2 dBm at the top of Clock tower is in the range of the estimation. We conclude that the interference through the diffraction mechanism will not cause any problem to IMT-2000/UMTS users at near the surface of Madrid urban area.
Document ID
20070034841
Acquisition Source
Jet Propulsion Laboratory
Document Type
Conference Paper
External Source(s)
Authors
Ho, Christian M.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Sue, Miles K.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Peng, Ted K.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Smith, Ernest K.
(Colorado Univ. Boulder, CO, United States)
Date Acquired
August 24, 2013
Publication Date
January 9, 2002
Subject Category
Communications And Radar
Meeting Information
Meeting: National Radio Science Meeting
Location: Boulder, CO
Country: United States
Start Date: January 9, 2002
End Date: January 12, 2002
Distribution Limits
Public
Copyright
Other
Keywords
telecommunications
diffraction
interference
propagation
S-band

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