Radio communication system with adaptive polarization

Abstract

A radio base station having a plurality of directional sector antennas for providing communications with outstations lying at different azimuth angles to the base station is disclosed in which the antennas transmit signals using one or both of two orthogonal polarizations such as left hand or right hand circular antennas and polarization and which also measures interference levels on different frequency channels that are used for allocating an optimum channel and polarization for connecting a call. Each of the outstations comprise at least one antenna of selectable polarization.

What is claimed is:  
     
         1 . A radio base station comprising: 
 a base receiver means for receiving a preferred polarization indication; and    a base transmitter means for transmitting to said subscriber terminal using said preferred polarization.    
     
     
         2 . The radio base station of  claim 1  wherein said preferred polarization indication is indicated by an electromagnetic wave polarization of a transmitted signal received by said base receiver means.  
     
     
         3 . The radio base station of  claim 1  wherein said preferred polarization indication is indicated by a bit flag.  
     
     
         4 . The radio base station of  claim 2  wherein said flag is set for one of RHC and LHC.