Wireless Communication Channel Purification for Urban Utility Tunnel Based on Sector Pattern Antenna Array.

In the urban utility tunnel, wireless communication severe serious multi-path effect, which causes significant fast fading and results in uniformity of the coverage. An antenna array which consists of five antenna elements with very simple structure is proposed in this paper for the purification of the multi-path communication channel in urban utility tunnel. The proposed antenna array is capable of operating at three frequency bands which can well satisfy the requirements of collaborative deployment of multiple communication systems in urban utility tunnel. Moreover, the sector radiation pattern of the antenna array has narrow HPBW on cross section of the tunnel and very wide HPBW on vertical plane along the tunnel, which conforms to the physical structure of the tunnel. Therefore, it can greatly reduce the reflection in the tunnel, purify the multi-path environment in the tunnel, and effectively improve the uniformity of wireless coverage in the tunnel.