Multi-beam adaptive base-station antennas for cellular land mobile radio systems

The authors address the problem of meeting the proliferating demands for mobile telephony within the confinements of the limited radio spectrum allocated to these services. A multiple-beam adaptive base-station antenna is proposed as a major system component in an attempt to solve this problem. The approach is demonstrated by employing an antenna array to resolve the angular distribution of the mobile users as seen at the base-station site, and then using this information to direct beams towards the mobiles in both transmit and receive modes. The energy associated with each mobile is thus confined within the addressed volume, greatly reducing the number of co-channel cells. For a given performance criterion, this results in an increase in the spectral efficiency or capacity of the network. The concept is demonstrated using results generated by a computer simulation of a simplified mobile scenario. The realization of a fully adaptive base-station antenna test rig is discussed