Popis: |
In this paper, the power allocation of Nonorthogonal multiple access (NOMA) for secondary users (SU) in a Cognitive Mobile Radio Network (CMRN) is studied. In the proposed scheme, SUs produce interference to the primary mobile network, which consists of two transmitters $(Tx_{p})$, one Long Term Evolution (LTE) and Wireless Fidelity (WiFi), both access technologies. There are also primary users (PU) of these technologies, converting them into a heterogeneous mixed network, main characteristics of 5G communications. The interference of the SUs must be less than the predefined threshold. On the other hand, the Signal-to-interference-plus-noise ratio (SINR) must also be greater than said threshold, otherwise, an interruption occurs and the Probability of non-Detection of PU increases, decaying the total bit rate and the spectral efficiency of the link. To improve the spectral efficiency and the Probability of non-Detection of the structured network vs SINR, a NOMA scheme is proposed to be adapted to the CMRN (CMRN-NOMA). The optimal power allocation coefficients of the SU are derived. The numerical results of the simulation are compared with a traditional OMAOFDM scheme and a Cooperative OMA scheme, noting that the proposed scheme achieves a higher spectral efficiency and lower Probability of non-Detection compared to traditional schemes such as conventional orthogonal multiple access. |