Cross-polarization interference cancelation (XPIC) performance in presence of non-linear effects

Microwave technology, used in main points of mobile backhaul, has now evolved to take advantage of the introduction of Internet Protocol (IP) into the backhaul network to drive higher capacities, increased frequency efficiency, increased flexibility, and optimal cost by combining a number of features to enable true gigabit transport speeds. One of those evolutions regards to the frequency reuse schemas like Co-Channel Dual Polarization (CCDP), which uses two parallel communication channels over the same link with orthogonal polarizations. Due to the nature of these systems, it is inevitable that cross-polar interference occur (e.g. rainfall, multipath, equipments imperfections...), where Cross-Polarization Interference Cancellation (XPIC) technology is adopt as a countermeasure against that interference. However, this cancelation block, normally located at baseband level, process signals that can be affected by non-linear impairments. This paper shows the performance achieved by two XPIC configurations, based on newly introduce XPIC model, in the presence of Saleh model non-linear element, placed at transmitter, for a 256-quadrature amplitude modulation (QAM) signal. CCDP system, which includes XPIC, is simulated using Simulink tool from Mathworks.