Automatic transmit power control in XPIC configuration for wireless applications

A system for automatic transmit power control in a radio communication system employing a co-channel dual-polarized radio link between a first radio station and a second radio station, the system comprising:

• a first radio receiver adapted for receiving a horizontal polarized signal transmitted from said second radio station to said first radio station;
• a second radio receiver adapted for receiving a vertical polarized signal transmitted from said second radio station to said first radio station;
• an estimating unit in said first radio receiver adapted to estimate a received power level value, PRxH, from said received horizontal polarized signal;
• an estimating unit in said second radio receiver adapted to estimate a received power level value, PRxV, from said received vertical polarized signal;
• a horizontal modem adapted to determine a cross polarization interference level value, XPIH, from said received horizontal polarized signal supplied by said first radio receiver;
• a vertical modem adapted to determine a cross polarization interference level value, XPIV, from said received vertical polarized signal supplied by said second radio receiver;
• a digital control block, in said horizontal modem, adapted to determine a power corrections value ΔPTxH;
• a digital control block, in said vertical modem, adapted to determine a power corrections value ΔPTxV;
• wherein said first radio receiver is further adapted to transmit said determined power correction value ΔPTxH to said second radio station using a service channel, and wherein said second radio receiver is further adapted to transmit said determined power correction value ΔPTxV to said second radio station using said service channel;
• a first radio receiver in said second radio station adapted to receive said receive power correction value ΔPTxH ;
• a horizontal modem in said second radio station adapted to adjust a transmit power of said first radio receiver in said second radio station based on said received said power corrections value ΔPTxH
• a second receiver in said second radio station adapted to receive said receive power correction value ΔPTxV;
• and
• a vertical modem in said second radio station adapted to adjust said power of said second radio receiver in said second radio station based on said received said power corrections value ΔPTxV,
• wherein said power correction values are independently determined from said estimated received power level values and a target power value, PWTG, under a condition that said power correction values do not exceed a cross polarization interference threshold level value, XPITH, such that XPITH ≦XPIH +ΔPTxH−ΔPTxVand XPITH ≦XPIV +ΔPTxV−ΔPTxH, and
• wherein said cross polarization interference threshold level value is based on said cross polarization interference level values and said power corrections values.