The Signal Subspace Artificial Noise Space-Hopping Method of Physical Layer Security

Existing artificial noise method adds artificial noise into the null space of legal channel to reduce the probability of being intercepted when sending confidential signal, if the antenna of eavesdropper is not less than the transmitter, it is disable. To solve this problem, the signal subspace artificial noise space-hopping method of physical-layer-security is proposed. Transmitter randomly selected the signal subspace to transmit confidential signal, and added artificial noise to the signal subspace. The legitimate receiver selects the corresponding signal subspace according to the Space-hopping pattern, and removes the artificial noise superimposed in the confidential signal using the agreed artificial noise, then modulates the confidential information. The eavesdropper unknown Space-hopping pattern and the agreed artificial noise, cannot find the signal subspace and remove the artificial noise superimposed in the confidential signal, so cannot eavesdrop confidential information. Simulations show that legitimate receiver’s SNR loss less than 3dB, and the symbol error rate of eavesdropper close to 0.75 with QPSK modulation.