Shadow fading analysis over asymmetric beam channel at 2.1 GHz in outdoor scenarios

In this letter, we investigate the radio propagation characteristics in an open outdoor place through a frequency-domain channel measurement campaign at a frequency band of 2.1 GHz via asymmetric beam patterns. Specifically, we focus on the large-scale fading characteristics and analyze the transceivers' separation-dependent and boresight direction-dependent received power, shadow fading (SF), and SF auto-correlation properties under the case of perfect beam alignment. Furthermore, the effects of asymmetric beamwidths are also thorough investigated. The measured results reveal that transceivers' beams can reduce the shadow fading variances evidently in contrast to the omnidirectional antennas' case. Besides, it is found that the pattern where mobile receiver (Rx) uses narrow beams and static transmitter (Tx) adopts the omnidirectional antenna yields a high SF auto-correlation value compared to the other beam patterns. The conclusions help to understand the impacts of variable beamwidths on radio propagation.