Measured Comparison of Dual-Branch Signaling Over Space and Polarization Diversity

Polarization diversity is an efficient alternative to space diversity as it cuts the antenna spacing requirements in half, but comparable results to spatially separated antennas need to be realized for practical implementation to take place. A dual feed square patch antenna has been chosen to demonstrate a complete system evaluation from the antenna design to symbol error rate (SER) performance of polarization diversity. The patch antenna has been designed with vertical and horizontal polarizations, which are well isolated at 2.4 GHz. The beam patterns were measured in the anechoic chamber on The University of Texas at Dallas (UTD) campus. The nature of the beam patterns greatly influenced the results, which have been reported in line-of-sight (LOS) and nonline-of-sight (NLOS) indoor environments in the Erik Jonsson Engineering and Computer Science North (ECSN) building at UTD. Performance evaluation has been developed for 1 × 1, 2 × 1, and 2 × 2 systems based on channel gain, channel correlation, and SER. The dual feed patch antenna performs more consistently as the environment changes from LOS to NLOS due to the low channel correlation and the complementary nature of the vertical and horizontal beam patterns.