Robustness to Digital Power Adjustment in Transmit Power Allocation for Poor Conditioned LPWA End Devices

In this study, we investigate robustness to power adjustment using digital settings at low-power wide-area (LPWA) module and a digital step attenuator in transmit power allocation for LPWA end devices under poor conditions, that is, high propagation loss to gateways. Traditionally, performance improvement techniques for end devices under poor conditions have been studied. In conventional techniques, employing analog stepless attenuator is assumed to adjust the transmit power at each end device. However, employing analog stepless attenuator at the end devices is not practical because each end device automatically adjusts its own transmit power. Therefore, we investigated the effect of the digital step attenuator and digital settings at LPWA module on the conventional techniques. Computer simulation results are presented to elucidate the characteristics of the conventional technique with the digital step attenuator and digital settings at LPWA module.