In a cognitive radio environment with at least three cognitive radio terminals, terminals 1 and 2 have an active link. Terminal 3 estimates the link quality, and if it is deemed good terminal 3 transmits over the frequency band in use on the link. Terminal 3 then monitors the link between terminals 1 and 2 to quantify its interference on it. If no interference is detected terminal 3 can increase its power. If terminals 1 and 2 change their modulation terminal 3 deems its interference too severe and either reduces power or finds another frequency band. Terminal 3 can use blind modulation detection for the link between terminals 1 and 2, and estimate link quality based on the type of modulation in use.