Secure MIMO cognitive networks based on spatial LDPC codes

The existing cognitive radio (CR) systems lack the ability to deal with the attack of a pretended primary user (PPU), which can palsy cognitive network by sending some random signal at the frequency band of CR network. To solve the problem, in this paper, a secure cognitive radio (CR) system is proposed. We develop a spatial LDPC code, which combines MIMO technique and low density parity check (LDPC) codes to cancel the electronic interference of PPU. In the proposed scheme, the spatial LDPC code depends on the wireless channel between the CR mobile station (MS) and CR base station, so different CR MS has its own spatial LDPC code. The spatial LDPC codes in CR network can very with channels, they can be recovered by the CR receivers from the attacked bits of PPU. The simulation results in Rayleigh flat-fading channel show that CR MIMO system with the proposed spatial LDPC codes can effectively cancel electronic interference from PPU.