This paper considers massive Internet of Things systems, especially for LoW Power Wide Area Networks, that aim at connecting billions of low-cost devices with multi-year battery life requirements. Current systems for massive Internet of Things exhibit severe problems when trying to pursue the target of serving a very large number of users. In this paper, a novel asynchronous spread spectrum modulation, called Golden Modulation, is introduced. This modulation provides a vast family of equivalent waveforms with very low cross-interference even in asynchronous conditions, hence enabling natural multiuser operation without the need for inter-user synchronization or for interference cancellation receivers. Thanks to minimal interference between waveforms, coupled with the absence of coordination requirements, this modulation can accommodate very high system capacity. The basic modulation principles, relying on spectrum spreading via direct Zadoff-Chu sequences modulation, are presented and the corresponding theoretical bit error rate performance in an additive white Gaussian noise channel is derived and compared by simulation with realistic Golden Modulation receiver performance. The demodulation of the Golden Modulation is also described, and its performance in the presence of uncoordinated multiple users is characterized.

翻译：本文考虑大规模物联网系统，特别是低功耗广域网，其目标是在满足多年电池寿命要求下连接数十亿低成本设备。当前的大规模物联网系统在追求服务极大量用户的目标时存在严重问题。本文提出一种新型异步扩频调制——黄金调制（Golden Modulation）。该调制方式提供庞大等效波形族，即使在异步条件下也能保持极低的交叉干扰，从而无需用户间同步或干扰消除接收机即可实现自然的多用户操作。得益于波形间的最小干扰和无需协调的特性，该调制方式可实现极高的系统容量。本文阐述了基于直接Zadoff-Chu序列扩频的基本调制原理，推导了加性高斯白噪声信道下的理论误码率性能，并通过仿真与黄金调制接收机的实际性能进行了对比。同时描述了黄金调制的解调方法，并表征了其在非协调多用户场景下的性能。