Co-channel Interference and Polarization Dependent Loss Mitigation in Wireless SISO Communications Standards

Mission critical narrow-band wireless communications standards such as IEEE 802.15.4g Smart Utility Network (SUN), Project 25, TETRA, ZigBee and custom SCADA systems were defined as Single Input Single Output (SISO) systems. As a result they lack built in provisions for smart multiport transceivers and associated antennas. These and other standards often lack channel coding techniques and may implement non-coherent modulation. Yet these systems are increasingly overwhelmed by interference in the form of network congestion, secondary users and out of band induced receiver intermodulation products. These networks operate in highly scattered environments that include multipath fading and Polarization Dependent Loss (PDL). This paper reviews multi-polarized antenna arrays and algorithms that exploit polarization scattering in the channel to mitigate both PDL and interference. These antennas and algorithms can be overlaid in new and replacement equipment providing Dynamic Spectrum Access (DSA) and an average 23dB Signal to Interference plus Noise Ratio (SINR) link budget improvement for mission critical SISO communication standards.