Cancellation of crosspolarisation for modulated orthogonally polarised signals is feasible. Some networks are presented. The most interesting lie in baseband processing.
Sobieski, P., & Delogne, P. (1980). Adaptive crosstalk cancellation for crosspolarised digital transmissions. Electronics Letters, 16(10), 385-387. https://hdl.handle.net/2078.5/149084 (Original work published 1980)