In this letter we analyze the effect of directional antennas at the base station on the Doppler spectrum. It is well known that the Doppler spectrum is dependent on the probability density function (pdf) of the angle-of-arrival (AOA) of the multipath components at the mobile unit and the direction of the motion of the mobile. The Doppler spectrum is U-shaped as noted by Clark , when the pdf of the AOA of the multipath components at the mobile is uniform. Here, however, we study the Doppler fading at the base station and assume that the scatterers are uniformly located around the mobile within a circle and derive the pdf of the AOA of the multipath components at the mobile when directional antennas are used at the base station.
ASJC Scopus subject areas
- Modeling and Simulation
- Computer Science Applications
- Electrical and Electronic Engineering