2. Propagation Modeling

The design of spectrally efficient wireless communication systems requires a thorough understanding of the radio propagation channel. This chapter emphasizes land mobile radio channels, including those found in cellular land mobile radio systems and mobile ad hoc networks including vehicle-to-vehicle channels. The chapter first treats the characteristics of the complex faded envelope in frequency non-selective (flat) fixed-to-mobile channels that are typically found in cellular land mobile radio systems, including the received envelope and phase distribution, envelope correlation and spectra, level crossing rates and fade durations, and space-time correlation. Afterwards, mobile-to-mobile channels are considered. This is followed by a statistical characterization of frequency-selective fading channels, and treatment of polarized fading channels. The chapter continues with a discussion of simulation techniques for fading channels, including filtered white noise, sum of sinusoid techniques such as the classical Jakes’ technique, and techniques for generating multiple uncorrelated faded envelopes. Advanced simulation methodologies are discussed including wide-band simulation models such as the COST207 and COST259 models, symbol-spaced simulation models, and mobile-to-mobile simulation models. The chapter goes on to discuss modeling and simulation techniques for long term fading or shadowing. Finally, the chapter wraps up with theoretical and empirical path loss models, including the famous Okumura–Hata model, Lee’s model, various COST models, and 3GPP mm-wave path loss models.