Improving the Security in Cellular Communications Networks with adding Artificial Noise by method Non-Orthogonal Resource Allocation Techniques

The Non-orthogonal multiple access (NOMA) is known as a bandwidth efficient access method for fifth generation wireless systems. Unlike the conventional orthogonal multiple access method, which uses only one subcarrier to send information simultaneously, NOMA uses the power domain to serve multiple users from a number of subcarriers simultaneously. In previous attempts, the superiority of the non-orthogonal multiple access method has been proven to be the orthogonal access method of security-to-listening, which state by the Secrecy Sum Rate (SSR), but the superiority of the overall NOMA secrecy sum rate over the OMA, can’t be seen a lot of difference between them. The paper attempts to increase the secrecy sum rate by adding artificial noise along with the user's signal in the transmitter. In this way, legitimate users receive artificial noise signal and, as soon as they arrive, they remove this signal from the received signal, but the eavesdropper assume it is the signal of a legitimate user and they use a lot of energy to decode it. This will reduce the eavesdropper rate then reduce the listening probability. The results obtained in this paper show that, for example, in a specific SNR such as 10 dB, the total secrecy sum rate (SSR) for the orthogonal multiple access method is about 0.1, for the common non-orthogonal multiple access method is about 0.25 and for the non-orthodontic multiple access method with using the artificial noise is about 1 bit per second per hertz.