Polarization diversity and equalization of frequency selective channels in telemetry environment for 16APSK

Providing RHCP and LHCP outputs from the antennas vertical (V) and horizontal (H) dipoles in the resonant cavity within the antenna feeds is the current practice of ground-based station receivers in aeronautical telemetry. The equalizers on the market, operate on either LHCP or RHCP alone, or a combined signal created by co-phasing and adding the RHCP and LHCP outputs. In this paper, we show how to optimally combine the V and H dipole outputs and demonstrate that an equalizer operating on this optimally-combined signal outperforms an equalizer operating on the RHCP, LHCP, or the combined signals. Finally, we show how to optimally combine the RHCP and LHCP outputs for equalization, where this optimal combination performs as good as the optimally combined V and H signals.