Vector channels for smart antennas - Measurements statistical modeling, and directional properties in outdoor environments

In wireless communications, smart antenna systems that employ antenna array s coupled with adaptive signal-processing techniques at the basestation imp rove capacity, coverage, and trunking efficiency. However, design and perfo rmance analysis of smart antenna systems strongly depend on channel propaga tion characteristics of signals present at the antenna array, the so-called vector channels, Here, variation of narrow-band vector channels (spatial s ignatures) due to a moving terminal is studied in typical suburban settings . Vector channel measurements are taken using a real-time smart antenna sys tem with a uniform circular array at the basestation and a mobile transmitt er at several locations. Two different wireless scenarios. namely, pedestri an and car mobile, are implemented to emulate the random movement of the mo bile user. In each scenario, the mobile transmitter locations are chosen so that there exists line-of-sight (LOS), nonline-of-sight (NOLOS), or both L OS and NOLOS (mixed) propagation to the basestation, We find that in all ca ses, the Beta distribution can be used to empirically represent the spatial signature correlations and that large spatial diversity exists in NOLOS ca ses compared to LOS cases. Also, direction-of-arrivals mostly do not change much with movement in a suburban environment.