【摘要】 6G大规模通信场景迫切需要使用新型多址技术解决海量终端随机接入问题，其它多种场景也需要6G新型多址以增加系统容量、降低接入时延、提高传输可靠性，因此研究6G新型多址势在必行。分析了6G新型多址与5G非正交多址的不同点，研究并评估了一种典型的新型多址技术-稀疏交织多址在AWGN信道和平坦Rayleigh衰落信道性能。稀疏交织多址的信号传输分为两部分，前导信号传输，用于用户激活检测和信道估计；数据传输部分，多用户信号复用到一起，使用比特重复和填零来抑制多用户干扰。研究了压缩感知矩阵维度、激活用户数和前导碰撞概率的关系。研究发现压缩感知矩阵大小和类型影响前导检测的性能；信道编码对6G新型多址数据传输部分性能有较大影响；衰落信道下使用两接收天线理想用户激活检测和信道估计可以支持上千用户数据传输，因此6G新型多址瓶颈可能不在数据传输部分，而在前导设计部分。更多还原

【Abstract】 The large-scale communication scenarios in 6G urgently require novel multiple access technologies to address the issue of massive random access. Also, various other scenarios also need 6G novel multiple access solutions to increase system capacity, reduce access latency, and improve transmission reliability. Therefore, it is imperative to investigate novel multiple access technologies for 6G. This paper analyzes the difference between 5G non-orthogonal multiple access and 6G novel multiple access, and evaluates the performance of a novel multiple access-sparse interleaver division multiple access(SIDMA) over additional Gaussian white noise(AWGN) channel and flat Rayleigh fading channel. Specifically, the signal transmission of SIDMA can be divided into the preamble and data transmission parts. Preamble is employed for user activity detection and channel estimation, and in data transmission part, multi-user signals are multiplexed together where bit repetition and zero-padding are used for multi-user interference suppression. The results show that the size and type of the compress sensing matrix affect the performance of preamble detection, and channel coding has a considerable impact on the data transmission performance in in 6G novel multiple access. Under fading channels, the number of access users can be substantially increased through two receive antennas with ideal user activity detection and channel estimation. This implies that the bottleneck of 6G novel multiple access may lie in the preamble part rather than data transmission part.更多还原