On a vehicular speed response type configuration of adaptive antenna for down link mobile communications

摘要

Weights update of adaptive antenna will not be accurate in a nonstationary environment such as in the down link line-of-site mobile communications because specular component (direct wave) of received signal has a large power and is affected by the influence of Doppler shift. The main purpose of this paper is to develop an adaptive antenna which overcomes the problem described above. This paper proposes a vehicular speed response adaptive antenna (VSR-AA) for the down link mobile channels and evaluates the performance in a Nakagami-Rice fading environment by computer simulation. VSR-VCO plays an important role in the proposed VSR-AA for the compensation of the Doppler shift of direct wave. As a result, it is observed that E{sub}b/N{sub}0 required for proposed VSR-AA is 8dB less than that for conventional AA at bit error rate (BER) of 10{sup}(-2) under several conditions (8-element antenna, Rice factor 5.0, f{sub}DT=0.05). And it is also observed that BER of the proposed VSR-AA remains constant with favorable quality under almost alt conditions of f{sub}DT.