6.1. Wireless Multipath Channel Models, Environment, and Signal Parameters6.1.1. The Macrocell Environment6.1.2. The Microcell Environment6.1.3. Angle Spread6.1.4. Measuring Time Variation of the Channel6.2. Spatio-Temporal Channel Models for Smart Antennas6.2.1. Lee’s Model6.2.2. Stapleton’s Extension of Lee’s Model6.2.3. Discrete Uniform Distribution6.2.4. Geometrically Based Single Bounce Statistical Channel Models6.2.5. The Geometrically Based Single Bounce Circular Model (Macrocell Model)6.2.6. The Geometrically Based Single Bounce Elliptical Model (Microcell Model)6.2.7. The Gaussian Wide Sense Stationary Uncorrelated Scattering (GWSSUS) Model6.2.8. Gaussian Angle-Of-Arrival (GAA)6.2.9. Time-Varying Vector Channel Model (Raleigh’s Model)6.2.10. Two GSM Simulation Models (TU and BU)6.2.11. The Typical Urban (TU) Model6.2.12. The Bad Urban (BU) Model6.2.13. The Uniform Sectored Distribution Model6.2.14. Modified Saleh-Valenzuela’s Model6.2.15. Extended Tap-Delay-Line Method6.2.16. Elliptical Subregions Model (Lu, Lo, and Litva’s Model)6.2.17. Measurement Based Channel Model6.2.18. Ray Tracing Models6.3. Spatial Channel Measurements6.4. Application of Spatial Channel Models6.5. Summary