Digital linear GFSK demodulator for IoT devices

Companies and developers of emerging Internet-of-Things (IoT) technologies consider Bluetooth low-energy (BLE) standard as a strong candidate to be the backbone of wireless IoT devices and support their low-power requirements. Likewise, the BLE has adopted Gaussian frequency shift-keying (GFSK) signalling due to its power and spectral efficiencies, which are the most fundamental performance criteria for modulation schemes. For this reason, it is worthwhile to research and develop transceivers that maintain these advantages and achieve a low-complexity implementation for the digital modulator and demodulator. Different techniques have been proposed for this purpose, such as hardware usage optimisation, efficient pulse shaping and decomposition of the signal. This study presents a novel linear GFSK demodulator which has the following attractive advantages: low complexity, near-optimal performance in the additive white Gaussian noise channel and the possibility of operating with different GFSK modulators (with a nominal modulation index of 0.5) so it could be applied in BLE devices. In addition, the theoretical error probability is obtained and compared with simulation results.