Evaluation of the BER Performance of LoRa Communication using BICM Decoding The patented LoRa physical layer adopts FEC codes that are essentially derived from the simple (7,4) Hamming code. The underlying coding rates of transmitted LoRa signals could vary between 45 and 48. The inherent capabilities of such codes are restricted to a mere error detection for the (5,4) code configuration and limited to single error correctiondouble error detection when the (8,4) code setting is used. On the other hand, LoRa modulation could be categorized as a form of multidimensional orthogonal signaling. This renders the opportunity to apply Bit Interleaved Code Modulation (BICM) to received LoRa signals with the potential of maximizing the coding gains that could be attained from the simple FEC codes deployed within commercial LoRa chips. In this paper, we apply the concept of BICM to LoRa signals and investigate the associated BER performance within AWGN and Rayleigh channels. Furthermore, we explore the potential of applying iterative decoding (i.e., BICMID) in order to further enhance LoRa BER performance.

Fast and Reliable LoRabased Data Transmissions LoRaWAN is a recently proposed MAC layer protocol which manages communications between LoRabased gateways and enddevices. It has attracted much scientific attention due its physical layer characteristics, but mainly due to its versatile configuration parameters. However, it is known that LoRaWANbased transmissions suffer from extensive collisions due to the unregulated access to the medium. For this reason, various techniques that alleviate the burst of collisions have been proposed in the literature. In this paper, we deal with the problem of fast data delivery in LoRabased networks. We model a network where transmissions follow a Poisson process. We compute the average packet success probability per Spreading Factor (SF) assuming orthogonal transmissions. We, then, formulate an SF optimization problem to maximize the success probability given an amount of data per node and a maximum data collection time window. We show xe2x80x93 both theoretically and using simulations xe2x80x93 that the overall success probability can be improved by approximately 100% using optimal SF assignments. We validate our findings using a 10node testbed and extensive experiments. Despite that experiments reveal the existence of interSF interference, our solution still provides the best performance compared to other LoRaWAN configurations.