188results about How to "Realize demodulation" patented technology

The invention provides a simplified multiplexing white light interference fiber sensing demodulating device, which comprises a single-fiber two-way optical transmitting / receiving module, an optical fiber resonant cavity, a single-mode transmission fiber, and an optical fiber sensing array, wherein the single-fiber two-way optical transmitting / receiving module is composed of a semiconductor light source as the transmitting terminal, a semiconductor photodetector as the receiving terminal and related devices packaged together; and an optical fiber annular cavity is composed of an optical fiber coupler, an optical fiber self-focusing lens and a movable corner reflector. The device can achieve enquiry and measurement of a plurality of optical fiber sensors by embedding the single-fiber two-wayoptical transmitting / receiving module and the optical fiber resonant cavity in the single-mode optical fiber, and has the advantages of simple structure, easy implementation, no length restriction ofthe transmission cable, no influence caused by the external environment, and good stability and reliability. The device can be used for the measurement of physical quantities such as distributed deformation, strain and temperature, and can be used for multi-task sensing, multi-element sensing, local strain sensing, large-scale deformation sensing, etc.

The invention discloses a hybrid chaotic LPI (Low Probability of Interception) communication system design method. According to the method, firstly, sequence chaotic system design of a digital communication system is implemented, a digital chaotic sequence is generated, simultaneously, according to characteristics of a channel, generation of carrier continuous chaotic signals is implemented, and by cascading of the digital chaotic sequence and continual chaotic signals, design of a hybrid chaotic system is implemented; and a receiving end firstly implements detection of the continuous chaotic signals, generates a digital sequence and then implements demodulation of a discrete chaotic sequence. Digital chaotic time domain waveforms and frequency domains of the continuous chaotic signals have flatness and are similar with a spectrum of noise, and thus, the continuous chaotic signals have the very high hiding characteristic; and power spectra of the continuous chaotic signals are very similar with that of the environmental noise and meanwhile, are very low in probability of interception, and thus, implementation of cascading of the continuous chaotic signals and the digital chaotic sequence greatly improves hiding performance to a certain degree.