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Utilizing nonlinear ELF generation in modulated ionospheric heating experiments for communications applications
Author(s) -
Jin G.,
Spasojevic M.,
Cohen M. B.,
Inan U. S.
Publication year - 2013
Publication title -
radio science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.371
H-Index - 84
eISSN - 1944-799X
pISSN - 0048-6604
DOI - 10.1002/rds.20014
Subject(s) - modulation (music) , electrojet , noise (video) , atmospherics , bit error rate , harmonics , phase shift keying , waveform , ionosphere , acoustics , physics , frequency modulation , electronic engineering , computer science , telecommunications , radio frequency , radar , engineering , geophysics , meteorology , earth's magnetic field , channel (broadcasting) , quantum mechanics , voltage , artificial intelligence , magnetic field , image (mathematics)
Modulated high‐frequency heating of the D region ionosphere near the auroral electrojet can generate extremely low frequency (ELF; 3 Hz–3 kHz) radio waves. The modulated heating process is nonlinear and generates harmonics at integer multiples of the ELF modulation frequency. Quaternary phase shift keying, a digital modulation technique is applied to ELF waves to demonstrate transmission of digital data. Data were successfully decoded at a nearby receiver and the bit error rate computed. Square wave modulation of the high‐frequency heater results in stronger signals and hence a smaller bit error rate. Simulations of the communication system using ELF waveforms and noise signals derived from ELF observations are also conducted. These simulations show that using higher harmonics of the ELF signal to improve the signal‐to‐noise ratio can reduce the bit error rate, although only when these harmonics are below ~4.5 kHz because of radio atmospherics (sferics) generating strong impulsive noise at higher frequencies.