NOMA异步干扰消除技术

NOMA Asynchronous Interference Cancellation Technology

由于NOMA(Non-Orthogonal Multiple Access,非正交多址接入)技术能够提高系统的吞吐量和频谱效率,因而在空间信息传输中具有广阔的应用前景。针对NOMA在传输过程中必然面临的同步问题以及不同用户信号间的彼此干扰问题,提出了NOMA异步干扰消除方案。首先采用过采样使得输出符号之间的噪声分量彼此独立,然后利用过采样输出序列间良好的结构性,分别采用SIC(Successive Interference Cancellation,串行干扰消除)、BP(Belief Propagation,置信度传播)、MLSD(Maximum Likelihood Sequence Detection,最大似然序列检测)等对采样输出的序列进行信号检测。仿真结果表明,符号异步NOMA相比于同步NOMA具有更好的误码性能。

Non-Orthogonal Multiple Access（NOMA）has broad application prospects in space information transmission as it increases system throughput and spectral efficiency.Synchronization issues and mutual interference between different users are main problems for NOMA receivers.To solve the problems,we propose an asynchronous interference cancellation method for NOMA.First,an oversampling method that brings independent noise samples is presented.Then,by taking advantage of the good structure between the oversampling output sequences,we respectively implemented Successive Interference Cancellation（SIC）,Belief Propagation（BP）detection and Maximum-Likelihood Sequence Detection（MLSD）.Simulation results show that symbol asynchronous NOMA outperforms synchronous NOMA.