Joint spectrum sensing method for sensing primary user signal in the presence of cognitive user signal

The invention relates to a joint spectrum sensing method for sensing a primary user signal in the presence of a cognitive user signal, and relates to a spectrum sensing method in the technical field of cognitive radio. The method solves the problem of the existing spectrum sensing method that whether the primary user signal exists cannot be effectively detected when the cognitive user signal exists in the sensing frequency band. The method comprises the following steps: 1, detecting the cognitive user signal by a cognitive user signal sensing module SSSB, and outputting channel gain; 2, reproducing the cognitive user signal in the received signal by a cognitive user signal reproducing module SSR; 3, subtracting output result of the cognitive user signal reproducing module SSR from an input signal to obtain an input signal of a primary user signal sensing module PSSB; and 4, performing frequency spectrum sensing by the primary user signal sensing module PSSB to judge whether the primary user signal exists. The method is suitable for sensing joint spectrum sensing of the primary user signal in the presence of the cognitive user signal.