TITLE:
Stochastic Modeling and Power Control of Time-Varying Wireless Communication Networks
AUTHORS:
Mohammed M. Olama, Seddik M. Djouadi, Charalambos D. Charalambous
KEYWORDS:
Wireless Networks, Time-Varying Wireless Fading Channel, Impulse Response, Doppler Power Spectral Density, Stochastic State-Space Model, Stochastic Modeling, Optimal Power Control, Expectation Maximization, Kalman Filter
JOURNAL NAME:
Communications and Network,
Vol.6 No.3,
August
7,
2014
ABSTRACT: Wireless networks are
characterized by nodes mobility, which makes the propagation environment
time-varying and subject to fading. As a consequence, the statistical
characteristics of the received signal vary continuously, giving rise to a
Doppler power spectral density (DPSD) that varies from one observation instant
to the next. This paper is concerned with dynamical modeling of time-varying
wireless fading channels, their estimation and parameter identification, and
optimal power control from received signal measurement data. The wireless
channel is characterized using a stochastic state-space form and derived by
approximating the time-varying DPSD of the channel. The expected maximization
and Kalman filter are employed to recursively identify and estimate the channel
parameters and states, respectively, from online received signal strength measured
data. Moreover, we investigate a centralized optimal power control algorithm
based on predictable strategies and employing the estimated channel parameters
and states. The proposed models together with the estimation and power control
algorithms are tested using experimental measurement data and the results are
presented.