Abstract:

To improve the transmission rate of deep fading cognitive users in spectrum sharing satellite terrestrial network, a relay cooperative communication strategy with non-orthogonal multiple access (NOMA) is presented. For the proposed strategy, on one hand, the source node can utilize NOMA technology to broadcast information, and adaptively adjust the power allocation factor according to the channel characteristics. On the other hand, the transmission power of relay node with decode  and forward is reasonably set by the relay-source power ratio parameter. In the case, the proposed strategy can maximize the transmission rate of the cognitive user under the total power constraint. Numerical results show that, compared with the relay cooperative communication strategy with orthogonal multiple access, the transmission rate of the proposed strategy will improve by about 13.7% within a certain limit of the relay-source power ratio. Moreover, the total power of the proposed strategy will reduce by about 30% in the same transmission rate.