Frequency-Shift Chirp Spread Spectrum Communications with Index Modulation

TL;DR

This paper proposes a frequency-shift chirp spread spectrum system with index modulation that significantly increases data rates while maintaining similar error performance, supported by optimal and low-complexity detection algorithms.

Contribution

It introduces a novel FSCSS-IM system using orthogonal chirp combinations, offering higher data rates and efficient detection methods compared to traditional FSCSS.

Findings

Achieves higher data rates than conventional FSCSS.

Maintains similar bit-error performance.

Develops near-optimal low-complexity detection algorithms.

Abstract

This paper introduces a novel frequency-shift chirp spread spectrum (FSCSS) system with index modulation (IM). By using combinations of orthogonal chirp signals for message representation, the proposed FSCSS-IM system is very flexible to design and can achieve much higher data rates than the conventional FSCSS system under the same bandwidth. The paper presents optimal detection algorithms, both coherently and non-coherently, for the proposed FSCSS-IM system. Furthermore, a low-complexity non-coherent detection algorithm is also developed to reduce the computational complexity of the receiver, which is shown to achieve near-optimal performance. Results are presented to demonstrate that the proposed system, while enabling much higher data rates, enjoys similar bit-error performance as that of the conventional FSCSS system.