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Title: Interference from the Robledo DSN transmitters to central Madrid IMT-2000/UMTS Ssystem through terrain diffraction at s-Band
Authors: Ho, Christian M.
Sue, Miles K.
Peng, Ted K.
Smith, Ernest K.
Keywords: interference
Issue Date: 9-Jan-2002
Publisher: Pasadena, CA : Jet Propulsion Laboratory, National Aeronautics and Space Administration, 2002
Citation: National Radio Science Meeting, Boulder, Colorado, January 9-12 2002
Abstract: This 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 -1 15 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 Ih4T-2000/UMTS users at near the surface of Madrid urban area.
Appears in Collections:JPL TRS 1992+

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