Spectrum sharing communication system and method

The present application relates to a communication systemcomprisinga primarysystem, comprising a primary system transmitter and a primary system receiver. The communication system comprises a secondary system, comprising a secondarysystem transmitter and a secondary system receiver, wherein the primary system and the secondary systemshare at least partially the same frequency spectrum. The secondary system transmitter is configured to transmit information comprising first information of the primary systemtransmitter and second information of the secondary system transmitter. The present application relates also to mobile radio communication system comprising said communication system, a method for communicating and a computer program comprising instructions operable to cause a processor to perform the said method.