Two-Dimensional Evolutionary Spectrum Approach to Nonstationary Fading Channel Modeling

Broadband mobile communication systems experience fading over a wide frequency band, which induces severe intersymbol interference and drastic channel gain fluctuation, resulting in a time–frequency doubly selective fading channel gain. Most existing works on fading channel modeling assume wide-sense stationarity with respect to (w.r.t.) time and uncorrelated scattering w.r.t. delay. However, due to the time-varying movement of mobile terminals, fading is usually nonstationary w.r.t. time, i.e., the Doppler spectrum is nonstationary. In addition, electromagnetic signals reflected/scattered from the same clustter/object are correlated and may induce nonstationarity w.r.t. delay due to time-varying cluster environments, e.g., wind causes the movement of leaves, resulting in time-varying scattering of leaves. To model nonstationary broadband mobile fading channels, this paper introduces a two-dimensional evolutionary spectrum (2-D ES) approach, which is compatible with the power spectral density of a stationary process. Based on the 2-D ES, the authors also propose an estimation method to estimate the 2-D ES parameters from a trace (sample path) of a fading process. Furthermore, the authors show how to set up a simulator to generate a 2-D stationary or nonstationary fading process according to the developed 2-D ES framework.Using the 2-D ES approach, the authors analyze a class of Nakagami- $m$ channels which is nonstationary in both the time and frequency domains. Two examples are used to show the accuracy of the developed 2-D ES-based channel modeling approach.

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  • English

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  • Accession Number: 01598015
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Mar 15 2016 10:47AM