面向5G的非正交多址接入技术

在频谱资源受限的情况下，非正交多址接入（non-orthogonal multiple access，NOMA）技术由于其良好的过载性能而受到广泛关注。首先，提出了基于复杂度受限的NOMA理论设计模型；接着，对目前主流的NOMA 技术方案进行了研究分析，并针对每种方案给出了其设计原理；进一步，设计了基于期望值传播（expectation propagation，EP）的低复杂度接收机；最后，通过仿真比较了 NOMA 与传统正交多址接入（orthogonal multiple access，OMA）技术的性能。结果表明，NOMA较传统的OMA技术能够显著提升系统容量和误码率（block error rate，BLER）性能。

Key technologies of non-orthogonal multiple access for 5G systems

With the unprecedented increase of mobile data traffic brought by the wide proliferation of smart phones and tablet computers, the non-orthogonal multiple access (NOMA) has attained great attention due to its overloading capability in the case of limited spectrum resources. Firstly, the complexity-constrained NOMA design principle was proposed. Then, a comprehensive study of key NOMA schemes was conducted, in which the theory of each scheme was provided. Next, the low complexity expectation propagation (EP) based detectors were designed. Finally, the performance of NOMA and the conventional orthogonal multiple access (OMA) was compared via simulations. The simulation results illustrate that the NOMA has superior capacity and block error rate (BLER) than the conventional OMA.