A New Index Modulation for LoRa

LoRa (Long Range) is a widely adopted Internet-of-Things (IoT) technique, but its fatal limit low data rate. In this letter, we propose new index modulation for to increase the rate, in which multiple quasi-orthogonal chirps modulated under different spreading factors (SFs) are concurrently transmitted, thereby leveraging SF domain as means carry more information. Both coherent and non-coherent detection algorithms proposed also developed efficient forms. Numerical results demonstrate that scheme notably outperforms state-of-the-art techniques.