Wake-Up Signal Multiplexing with Non-Coherently Detected Waveforms

A wake-up signal (WUS) can be transmitted from the base station to the user equipment (UE) in order to power-on a UE that was put in sleep mode. The UE may have a dedicated radio receiver for the WUS, which is highly optimized for power efficient operation and the WUS preferably uses a simple waveform which can be non-coherently detected. Thus, multiplexing of WUSs on the same time-frequency resource cannot be done with classical code division multiplexing (CDM). We propose a new multiplexing method of WUSs which is performed prior to the modulator, which allows to use a non-coherently detected waveform. This can be formulated as an encoding problem and we discuss constructions of such multiplexing codes. In particular, we address methods with low complexity to demultiplex the WUSs. The results show that the proposed multiplexing scheme could outperform time division multiplexing (TDM).