The design of spectrally efficient wireless communication systems requires a thorough understanding of the radio propagation channel. This chapter emphasizes land mobile radio channels, particularly those found in cellular land mobile radio systems. The characteristics of the radio channel will vary greatly depending on the operating frequency, and the propagation environment, e.g., line-of-sight (LoS) versus non-line-of-sight (NLoS), stationary versus mobile transmitters, receivers and scatterers, and other factors. However, many of the concepts are of a fundamental nature and will apply, with appropriate modification, to other types of mobile radio channels as well, such as vehicle-to-vehicle and drone communication channels. The chapter begins with the mathematical modeling of multipath fading channels. The received envelope and phase distribution is derived, including Rayleigh and Rician fading and their effect on error probability. The channel time correlation and Doppler spectrum are studied. The simulation of flat faded land mobile radio channels is considered including filtered white noise and sum-of-sinusoids methods. This is extended to frequency-selective fading channels. The chapter wraps up with a treatment of shadowing and path loss models.