40results about How to "Increase multiplexing capacity" patented technology

A spreading code generating apparatus carries out M-sequence multiplication and zero value addition of generated orthogonal codes to obtain channel identification codes, and then carries out inverse Fourier transform of the channel identification codes to generate spreading codes and inverse spreading codes. A transmitting apparatus and a receiving apparatus store the spreading codes and the inverse spreading codes generated by the spreading code generating apparatus, respectively, and use a single code respectively selected from the stored codes to carry out spread spectrum communication. With the use of the spreading codes for spreading, the input signal is spread over a wide frequency band with uniform power on the frequency axis. Thus, transmission characteristics are improved, and multiplexing capacity is increased.

The invention relates to a micro-structure fiber optic Fabry-Perot cavity quasi based quasi-distributed sensor, which comprises a broadband light source (1), a fiber optic circular (2), a plurality of sensor units (3), a sensor-based optical fiber (4), an optical spectrum analyzer (5) and a data processor (6), wherein each sensor unit (3) is a micro-structure fiber optic Fabry-Perot cavity, and the sensor units are connected in series and are integrated on the sensor-based optical fiber (4); and three ports of the fiber optic ring device (2) are respectively connected with the broadband light source (1), the sensor-based optical fiber (4) integrating all sensor units, and the optical spectrum analyzer (5), and the optical spectrum analyzer (5) is connected with the data processor (6). The micro-structure fiber optic Fabry-Perot cavity quasi based quasi-distributed sensor has the advantages of large sensing capacity, simple structure, low cost, wide application prospect and the like.

The invention discloses a distributed sensor fiber as well as a preparation device and method thereof. The distributed sensor optical fiber comprises an outer layer which is an ultraviolet transparent coating layer (1) and an inner layer which is an optical fiber core, wherein a plurality of weak Bragg reflection period structures (2) which have identical physical structures and identical opticalproperties are continuously distributed on the optical fiber core at an interval of a section of delay optical fiber (4). When the optical fiber provided by the invention is used as a distributed sensing detection carrier, the sensing measurement range can be efficiently widened, and the sensing distance and concentration can be increased.

The invention discloses a device and a method for preparing a weak grating array with continuous wavelength change online. The device mainly comprises an optical fiber drawing tower system and an online grating inscribing system, wherein a phase mask plate is mounted on one platform, accurate and rapid regulation and control of the central wavelength of an inscribing grating are achieved, a rotating platform is controlled by a central control system, a rotating angle of the phase mask plate is changed in real time according tochange of the central wavelength of the inscribing grating. According to the method for preparing the weak grating array with the continuous wavelength change online, the grating is inscribed online based on a phase mask method, and the grating array with the same orcontrollable reflectivity and the center wavelength capable of continuously changing is prepared by rotating the angle of the phase mask plate and enhancing and compensating corresponding laser pulseenergy. The device is advantaged in that the weak grating array with continuous wavelength change can be prepared, the shadow effect and crosstalk influence between the identical gratings can be effectively eliminated, and use requirements of a high-capacity dense optical fiber sensing network are further met.