Noise in wireless systems produced by solar radio bursts

Abstract

We have carried out an investigation of 40 years of solar radio burst data in a wide range of frequencies that have been reported by observing stations around the world during 1960–1999. The data were compiled by the National Geophysical Data Center of the National Oceanic and Atmospheric Administration. This period covers three full and two partial solar cycles. We find that the number of bursts per day with amplitudes >103 solar flux units (SFU) falls as an approximate power law with increasing flux level for the frequency bands investigated(1–10 and 10–20 GHz). Also, the number of events with peak flux density >103 SFU varies, as expected, with the solar cycle in the bands investigated (1–2, 2–4, and 4–10 GHz). We discuss the rate of occurrence of events (>103 SFU) in the context of the noise levels in typical wireless communications systems. We find that statistically, depending upon wireless system parameters, several solar events per year are likely to occur that could cause severe interference in a given cell site during solar maximum periods.