Sensing Bandwidth Enhancement by Utilizing Negative Frequency Bandwidth in Quasi-distributed Acoustic Sensing System

With the increasing demand for high-sensitivity acoustic sensing in the fields like infrastructure, railway system, oil and gas pipeline monitoring and so on, quasi-distributed acoustic sensing (QDAS) is playing an important role in these scenarios. However, the sensing bandwidth is the limitation of QDAS, which can be improved with the method of frequency-division-multiplexing (FDM). But FDM requ...