Analysis of Multipath Outage in the Presence of Thermal Noise and Interference on Multi-Level Modulation Systems

Takehiro MURASE  Kozo MORITA  

IEICE TRANSACTIONS (1976-1990)   Vol.E68   No.12   pp.844-851
Publication Date: 1985/12/25
Online ISSN: 
Print ISSN: 0000-0000
Type of Manuscript: PAPER
Category: Transmission Systems

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A new practical method of predicting outage probability caused by multipath fading in the presence of thermal noise and interference has been presented for multi-level digital radio systems. First, the linear amplitude dispersion (LAD) method using the waveform factor was derived. Outage probability due to ISI can be easily predicted for any system and any paths using this method. The validity of the method was confirmed in field experiments. Synergistic effects of noise and interference on outage were also discussed. Closed form expressions to evaluate the synergistic effects have been derived and the results were compared with those predicted by the power sum method. Both sets of results agree well. Analysis proved that synergistic effects depend only on the difference between flat fading margin and dispersive fading margin, and are independent of modulation scheme or path characteristics. The method presented here can be applied in a unified way to various systems having different modulation scheme, symbol rate, spectrum shaping, etc.