Symbol rate estimation for remote distributed microwave signal reception using photonic technique

Based on photonic technique, an approach to the symbol rate estimation of the remote distributed microwave signal reception is proposed and demonstrated experimentally. Firstly, the received microwave signal is applied to modulating the light wave under the carrier-suppressed double sideband (CS-DSB) modulation in the remote terminal, generating two optical sideband signals carrying the microwave signal. Then the two sidebands are transmitted to the central station through optical fiber links, and one of them is filtered out in the optical domain. After the photoelectric detection (PD), the microwave signal symbol rate can be obtained by analyzing the spectrum of the electrical signals. The proposed approach is verified via both simulations and experiments. In the simulations, the symbol rate of 0.8 GBaud or 6 GBaud is successfully extracted for pseudo-random binary signal (PRBS) with the carrier frequency at 60 GHz. At the same time, the symbol rate of 3 GBaud is extracted for PRBS signals with 25 GHz carrier frequency. In the experiments, the symbol rate at 3 GBaud or 5 GBaud is achieved when the carrier frequency is 25 GHz. The proposed approach has the advantages such as wide instantaneous bandwidth, low loss for remote transmission, availability for distributed monitoring, and strong immunity to electromagnetic interference, which would play an important role for the microwave signal analysis and estimation.