Improvement Physical Layer Security in MISO NOMA Using Directional Modulation Based on LFDA

In Non-orthogonal multiple access (NOMA), more power is allocated to a user with a weaker channel quality than to a user with a stronger channel. The strong user (SU) uses successive interference cancellation (SIC) for detecting the weak user (WU) symbols before detecting its symbols. This causes t the WU information to be intercepted at the SU. This paper uses directional modulation (DM) to create security. By using DM in a multi-input and single-output (MISO-NOMA) network, the WU data and SU data are protected from each other and eavesdroppers. This method eliminates the effect of the WU information on the location of the SU so the SU doesn’t need the SIC for detecting and eliminating the WU data. With no need for the SIC, the detection complexity is reduced for SU. Simulation confirms that this scheme creates security and a low bit error rate (BER) for transmitted information.