Regenerative sampling self-mixing receiver: A novel concept for low complexity phase demodulation

In this paper, a novel low complexity receiver concept for high-order differential phase demodulation is introduced for the first time. With a first hardware demonstrator, a high data rate of 300 Mbit/s is achieved without requiring a synthesizer for downconversion. A phase sensitive regenerative sampling approach is employed that integrates both low noise amplifier and automatic gain control using a free running switched injection-locked oscillator with no need for stabilization by a phase locked loop. Differential phase detection is achieved by quadrature self-mixing the regenerated signal with one path delayed by the symbol period. This approach is particularly attractive in combination with the switched injection-locked oscillator due to its constant high output power that allows for matching the mixer's best operating point. The proposed concept is demonstrated at 5.5 GHz with 8th order differential phase shift keying and a symbol rate of 100 MBaud/s. A short range data rate of 300 Mbit/s is achieved at a bit error rate below 1e-3.