免调度非正交多址接入上行链路的非2幂次长度二元扩频序列

为了解决5G大规模机器类通信场景下大规模接入和如何提高频谱效率的问题，该文针对免调度非正交多址接入(NOMA)系统上行链路，通过采用插入函数在2元Golay序列上插入元素的方法，提出具有低峰均功率比(PAPR)且长度为非2幂次的2元扩频序列集。仿真结果表明，得到的序列集具有低相干性，这为基于压缩感知的活跃用户检测提供了可靠的性能。同传统的Zadoff-Chu序列相比，新型2元序列集具有更小的字符集，便于实现。此外，所构造的序列PAPR最大为4，低于高斯随机序列和Zadoff-Chu序列，因此可以有效解决时域信号峰均功率比过高的问题。

Binary Spreading Sequences of Lengths Non-Power-of-Two for Uplink Grant-Free Non-Orthogonal Multiple Access

In order to solve the problem of mass access and how to improve spectrum efficiency in 5G massive Machine-Type Communication (mMTC) scenario, for the uplink grant-free Non-Orthogonal Multi-Access(NOMA) system, new sets of non-orthogonal binary spreading sequences with low Peak Average Power Ratio(PAPR) and lengths non-power-of-two is proposed by inserting elements into binary Golay sequences using insertion function. Simulation results confirm that the resulting sequence sets has low coherence, which provides reliable performance for active user detection based on Compressed Sensing (CS). Compared with the traditional Zadoff-chu sequences, the new binary sequence sets has a smaller alphabet set, which is easy to implement. Moreover, the resultanted sequences exhibit the PAPR of at most 4, which is lower than those for Gaussian and Zadoff-Chu sequences. Therefore, the problem of high peak-to-power ratio in time domain can be solved effectively.