CROSS POLARIZATION INTERFERENCE COMPENSATING DEVICE COMPRISING DECISION FEEDBACK CROSS POLARIZATION INTERFERENCE CANCELLERS

On receiving a symbol sequence carried by a first-polarization and a second-polarization signal of two orthogonally polarized signals and in order to cancel a cross polarization interference (XPI) component which leaks from the second-polarization signal into the first-polarization signal, a first decision feedback XPI canceller (43) is supplied with a before processed signal derived from the second-polarization signal and with a decided signal which is produced by a decision circuit (22) and which represents the symbol sequence carried by the second-polarization signal with an intersymbol interference component and another XPI component cancelled from the before processed signal. Another decision feedback XPI canceller (44) is similarly operable. Preferably, a first decision feedback equalizer (41) is supplied with another before processed signal derived from the first-polarization signal and with another decided signal which is produced by another decision circuit (21) and which represents the symbol sequence carried by the first-polarized signal with another intersymbol interference component and the first-mentioned XPI component cancelled from the last-mentioned before processed signal. A second decision feedback equalizer (42) is similarly used. Alternatively, a delay element is used instead of each decision feedback equalizer if the intersymbol interference components are negligible.