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Man-Made Noise Evaluation for Cryogenic Receiver Front-End

Shoichi Narahashi1,3, Kei Satoh1, Yasunori Suzuki1, Tetsuya Mimura2, and Toshio Nojima3
1. Research Laboratories, NTT DOCOMO, INC., Yokosuka, JAPAN
2. Intellectual Property Department, NTT DOCOMO, INC., Tokyo, JAPAN
3. Graduate School of Information Science and Technology, Hokkaido University, Sapporo, JAPAN

Abstract—This paper presents measured results of manmadenoise impact on an cryogenic receiver front-end(CRFE) in urban and suburban areas in the 2-GHz bandwith amplitude probability distribution (APD). The CRFEcomprises a high-temperature superconducting filter,cryogenically-cooled low-noise amplifier, and highly-reliablecryostat. The CRFE is expected to be an effective andpractical approach to attain efficient frequency utilizationand to improve the sensitivity of mobile base stationreceivers. It is important to measure the characteristics ofman-made noise in typical cellular base station antennaenvironments and confirm their impact on the CRFEreception with APD because if man-made noise has astronger effect than thermal noise, the CRFE would fail tooffer any improvement in sensitivity. The measured resultssuggest that the contribution of man-made noise in the 2-GHz band can be ignored as far as Wideband Code DivisionMultiple Access (W-CDMA) system is concerned. The manmadenoise is also measured in the VHF-band forcomparison with the 2-GHz band environment.

Index Terms—cryogenic receiver front-end, man-made noise,amplitude probability distribution, wideband code divisionmultiple access

Cite: Shoichi Narahashi, , Kei Satoh, Yasunori Suzuki, Tetsuya Mimura, and Toshio Nojima, "Man-Made Noise Evaluation for Cryogenic Receiver Front-End," Journal of Communications, vol. 3, no. 5, pp. 54-61, 2008.