基于非正交多址技术的协作中继传输方案

针对星地频谱共享网络中深衰落认知用户传输速率低的问题,提出了一种基于非正交多址接入(non-orthogonal multiple access,NOMA)的协作中继传输方案。该方案的源节点采用NOMA技术广播信息并根据信道特性自适应地调节功率分配因子,中继节点通过中继-源节点功率比参数合理设置其传输功率并进行译码转发,在功率受限情况下最大化认知用户的传输速率。数值分析结果表明,功率比在一定范围内时,与正交多址接入的协作中继方案相比,该方案的传输速率提高了13.7%左右;当两种方案传输速率相同时,该方案的功率节约30%左右。

Transmission scheme of cooperation relay based on non-orthogonal multiple access

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.