面向6G的非正交多址接入关键技术

The Key Technologies of Non-orthogonal Multiple Access for 6G Systems

非正交多址接入技术凭借其良好的过载性能被认为是满足下一代移动通信(6G)超大连接、超低时延和高可靠性需求的关键技术之一,但目前相关理论研究尚不充分,且其应用仍面临着接收机实现复杂度过高等问题。首先提出了复杂度受限下NOMA设计理论模型,接着给出了NOMA系统的发送端理论分析和接收端方案设计,进一步提出了一种基于可靠性的期望值传播算法,仿真结果表明在性能损失可接受范围内,复杂度较EP接收机降低了约35%,最后,将NOMA与多入多出技术相结合,进一步提升系统的性能,为低复杂度、逼近容量界的NOMA方案设计提供了理论和关键技术支撑。

Due to the good overloading capability,non-orthogonal multiple access(NOMA)is considered as one of the key technologies to meet the requirements of the next generation mobile communication system(6G),such as massive connection,ultra-low latency and high reliability.However,the relevant theories are insuffi cient and its applications are still challenged by the high-complexity of the receiver implementation and other diffi culties.This paper fi rstly proposes the complexity-constrained NOMA design principle and then provides the transmitter analysis and receiver design in NOMA systems.Furthermore,a reliability-aware expectation propagation(EP)algorithm is proposed and the simulation results illustrate that the proposed method reduces the computational complexity by about 35%relative to the conventional EP-based receiver with acceptable performance loss.Finally,the combination of NOMA and multiple-input multiple-output(MIMO)further improves the system performance,which provides theoretical and key technical support for the design of NOMA with low complexity and approaching capacity bound.