An advanced modulation technique for telemetry system used for smart capsules

This paper presents an enhancement on QPSK modulation technique for near field communication (NFC). The enhanced modulation is based on continuous-phase QPSK with Gaussian filtering during switch from one phase to the other. Signal processing is done digitally with minimum external discrete components for air interface. The telemetry system can be used to assist a smart capsule (slave) that can be swallowed to establish data communication with external device (master). The system is designed, simulated, and emulated on FPGA showing 20 dB attenuation on side-lobes of the spectrum.