Packet Recovery Latency of a Rate-less Polar Code in Low Power Wide Area Networks
Yi Yu, Lina Mroueh, Guillaume Vivier, Michel Terré · 2019
In this paper, we consider a Low Power Wide Area Networks (LPWAN) operating in a licensed-exempt band. In order to enhance the receiver sensitivity, low complexity repetition schemes that benefit from the time-varying channel condition are widely used. In this case, successful data recovery requires a significant channel variation from a bad to a good state depending on the data rate. This induces a relatively high decoding latency especially for slow time-varying channel. The main objective of this paper is to reduce the packet recovery latency by exploiting multiple channel states defined with respect to various transmission data rates, that are enabled by a rate-less polar code. We characterize the good channel sequence state of this code, and evaluate its latency performance in a slow and fast-time varying context.