Signal distribution in the azimuth, elevation, and time-delay domains in urban radio communication links

2004 ◽  
Vol 46 (5) ◽  
pp. 171-178 ◽  
Author(s):  
N. Blaunstein ◽  
E. Tsalolihin
Keyword(s):  
Time Delay ◽  
Radio Communication ◽  
Signal Distribution ◽  
Communication Links

scholarly journals Software Define Radio System for HF Noise Measurements

2017 ◽  
Vol 23 (3) ◽  
pp. 18-23
Author(s):  
Iulian Bouleanu ◽  
Vlad-Cosmin Vasile
Keyword(s):  
Time Spectrum ◽  
Radio Communication ◽  
Radio System ◽  
Different Types ◽  
Communication Links ◽  
Lightning Impulse ◽  
Noise Measurements ◽  
Radio Communication System ◽  
Technical Solutions ◽  
Reference Document

AbstractAccurate noise estimation in the HF band is a defining aspect in the evaluation of SNR for communication links. The reference document that specifies how different types of electromagnetic noise can be taken into account by radio communication system planners is the ITU-R Recommendation P.372.Meanwhile a series of studies have demonstrated that Gaussian noise in the HF band is not always valid because this band noise is strongly affected by atmospheric emission sources such as lightning impulse. This leads to the idea that a distribution suited to express the noise variance is the Bi-Kappa distribution. In addition, over the past decade, SDR devices and real-time spectrum analysers, which can be used to evaluate this noise, have registered explosive growth. This article indicates technical solutions and procedures used to estimate the noise level in the HF subband which can be used for Near Vertical Incidence Skywave (NVIS) communications and proposes a measurement system based on a SDR solution which meets these requirements.

scholarly journals Characterization and Investigation of Nonlinear Behaviour of Radio Refractivity during the Rainy and Dry Seasons in the Coastal Region of Nigeria

2021 ◽  
Vol 25 (7) ◽  
pp. 1155-1161
Author(s):  
A.E. Adeniji ◽  
E.M. Ajeigbe ◽  
K.S. Ojo
Keyword(s):  
Meteorological Parameters ◽  
Coastal Region ◽  
Nonlinear Effects ◽  
Nonlinear Behaviour ◽  
Radio Communication ◽  
National Space ◽  
Communication Links ◽  
Radio Signals ◽  
Quantification Analysis ◽  
Dry Seasons

The transmission and receiving of good quality of signals globally has been impaired due to the internal activities of the troposphere linked to the nonlinear behaviour of the meteorological parameters. This paper focusses on characterizing and investigating the nonlinear behaviour of radio refractivity during the rainy and dry seasons in the coastal region of Nigeria using temperature, pressure and relative humidity data collected over a period of two years by the Centre for Atmospheric Research, National Space Research and Development Agency (NASRDA) from Lagos state. Data obtained were analyzed by False Nearest Neighbour (FNN) and Recurrence Quantification Analysis (RQA). The results show that recurrence techniques are able to identify the periods where there are high predictability and low predictability. The investigation of nonlinear effects of meteorological parameters and the hydrometeors on the troposphere help to avoid fading of radio signals along with the radio communication links.

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