Dual Polarization Frequency Reuse in SATCOM: A Method to Counter Poor Cross-Polar Isolation

Utilizing orthogonal polarizations is a well-known frequency reuse technique in satellite communications (SATCOM) to provide additional spectrum in a given geographical region. However, in practice there will be a link degradation due to cross talk between the two polarization channels. The cross talk results from the combined effects of the antenna´s imperfect ability to distinguish between the two polarizations and channel depolarization effects. Greater cross-polar isolation (XPI) reduces the link degradation in terms of the received signal to noise plus interference ratio (SNIR). The effect of cross talk can be significant, limiting the benefits of using orthogonal polarizations. In this paper we evaluate the XPI impact in terms of received SNIR when using orthogonal polarizations. We then propose the use of a multiple input multiple output (MIMO) singular value decomposition technique (SVD) to mitigate the XPI impact.