Cross-Polarization Coupling Measured for 800 MHz Radio Transmission In and Around Houses and Large Buildings

The scatterers and reflectors that produce multipath propagation in the portable radiotelephone environment also scatter energy from the transmitted polarization into the orthogonal polarization. This cross-polarization coupling improves the signal quality on portable radio links by mitigating the effects of ranfom antenna orientation and by providing an additional signal path for diversity combining. Measurements were made of cross-polarization coupling at 800 MHz within and around eight suburban houses and within two commercial buildings. Nearly complete coupling between polarization was seen for all propagation paths except for a few residential paths having high co-polarized signal levels. Because of the high cross-polarization coupling, random orientation of portable radio sets will not cause significant degradation of signal quality.