Alamouti-NOMA Assisted Wireless Communication System

Abstract

We investigate a hybrid scheme that is a combination of orthogonal and non-orthogonal multiple access (NOMA) techniques. Specifically, we use Alamouti code for transmission of the symbols; each symbol contains the information of two or more users by utilizing NOMA-based technique. It is shown in the paper that the code rate of the proposed scheme is more than one, and it performs better than the conventional NOMA-based communication system. The closed-form expression of symbol error rate and diversity order is derived by using moment generating function-based approach. It is shown that the power allocation coefficient does not affect the diversity order.

Keywords

• Orthogonal space-time block codes (OSTBC)
• Alamouti code
• fading channels
• non-orthogonal multiple access (NOMA)
• multiple-input multiple-output (MIMO)
• M-ary phase-shift keying (M-PSK)