Design and Implementation of Transparent Cross-Polarization Interference Compensation in a Wideband Dual-Polarization Satellite Receiver

In this paper, simultaneous transmission on two orthogonal antenna polarizations in a polarization division multiplexing (PDM) fashion is studied for wideband satellite communication links using dual-polarization satellite receivers for the purpose of doubling the data rate. In order to mitigate the cross-polarization interference (XPI), a new digital blind and transparent XPI compensation method is proposed, coined as XPI correlation learning estimation and adaptive reduction (XPI-CLEAR). The received signal-to-noise-and-interference ratio (SNIR) and packet-error rate (PER) performance with this non-data-aided and non-decision-directed method is assessed in a comprehensively modelled XPI channel with effects such as depolarization due to atmospheric conditions, imperfect cross-polarization discrimination (XPD) of the antennas at the transmitter and the receiver, memory effects due to frequency selectivity of the XPD, and differential frequency offset (DFO) between the two channels. The application of the XPI-CLEAR method presents considerable energy efficiency improvements for all the studied XPI channel effects, and is particularly beneficial for higher order modulation. A low-complexity hardware implementation with symbol rates up to 500 MBaud validates the XPI-CLEAR method as a practical solution to increase the data rates of the satellite air interface and to achieve the doubling of the throughput of the satellite link by the use of PDM.