211results about How to "Simple demodulation" patented technology

The present invention relates to a method for controlling a touch sensor. The touch sensor comprises a support layer and an electrically conductive sensor structure thereon. The electrically conductive sensor structure forms a plurality of capacitors having a capacitance varying in response to a user touching or approaching the capacitor. The electrically conductive sensor structure comprises a piezoresistive material providing a resistance varying in response to a force being applied to the support layer. According to the method, an alternating electrical signal is supplied to the electrically conductive sensor structure for scanning the capacitors. An actuation position where the user touches the touch sensor is determined based on the alternating electrical signal and the capacitances of the capacitors. An electrical signal which is a function of the resistance of the electrically conductive sensor structure is detected and synchronously demodulated based on the alternating electrical signal.

In an orthogonal frequency division multiple access communication system, a base station transmits a quick paging signal simultaneously with a synchronization signal during the same transmission symbol time period. Even though these different signals are transmitted during the same transmission symbol time period, a periodicity of the synchronization signal is maintained to facilitate rapid and cost-effective synchronization by subscriber stations with the base station. The quick paging signal alerts subscriber stations about whether to stay awake for a subsequent page or to go into a power saving sleep mode.

In an adaptive modulation communication system that adaptively varies a modulation scheme for each transmit unit, a transmitting-side apparatus sets different error detecting units corresponding to bit position, and transmits data subjected to error detecting processing on a different error detecting unit basis corresponding to bit position, and a receiving-side apparatus performs demodulation independently for each of the error correcting units using different demodulation patterns to obtain received data.

The invention provides a low-power MSK non-coherent digital demodulating method by adopting the phase axis detection and a demodulator which consists of a phase axis generator, a quantizer, a phase detector, a judgment former, correlator groups, a sign judgment device and a clock selection circuit; wherein, the demodulator does not need an independent carrier frequency and a phase restoration circuit or a data restoration clock circuit; DSSS signals can directly de-spread by adopting the correlator groups without a clock and bit restoration circuit; the algorithm of the slopes of phase changes of base-band signals of PN code sequence is adopted in relative judgments, which can overcome the phase cumulative errors caused by the random clock skew of a sending terminal; in addition, the demodulator has a better compensation ability for frequency errors without special frequency compensation circuits; furthermore, the demodulating performance is unrelated with carrier phases and the synchronization performance of DSSS frequency spread and frames and signs is good. The MSK demodulator is characterized by simple demodulating method, low packet loss rate, few hardware expenses, strong anti-noise ability, low power, easy integration, and the like, and can be applied to modern high-end communication terminals.

The invention relates to a micro nano fiber vibration sensor based on a hollow fiber and belongs to the field of fiber sensing. A single-mode fiber, a hollow fiber and a solid core fiber are welded in sequence. The hollow fiber is a hollow cylindrical column. The center of the side surface of the circular column is provided with a groove, and the length in the axial direction of the groove needs to be smaller than the length of the hollow cylindrical column. The groove is formed by burning the side surface of the hollow fiber with a femto second laser. The invention solves the problem that a reflective surface formed when processing the fiber with the femto second laser has a low reflectivity or does not have a reflectivity; and the micro nano fiber vibration sensor is featured by small size, high resonance frequency, high temperature resistance, electromagnetic interference resistance and the like, and can be used for vibration measurement in high temperature environments.

The invention discloses an optical fiber geophone, which comprises a tilted optical fiber grating, a cladding-core energy recoupling structure, a polymer elastic tube, a supporting member, a shell and an optical fiber wire. One end of the polymer elastic tube is fixed on the supporting member. The other end is suspended to sense vibration, and the tilted fiber grating and cladding-core energy recoupling structure are all encapsulated in a polymer elastic tube; the outer side of the polymer elastic tube is protected by a shell, and the polymer elastic tube communicates with an external light source and photoelectric detection through an optical fiber wire The cladding-core energy recoupling structure is processed by a dislocation fusion splicing method or a fiber tapering method. The invention adopts a cladding-fiber core energy recoupling structure, which has a compact structure, and the structure is very sensitive to optical fiber micro-bending or optical fiber vibration, has high sensitivity, and the device demodulation is simpler and the demodulation cost is low.

The invention discloses a quasi-distributed sea water temperature salinity sensor, a measuring device and a method thereof. The sea water temperature salinity sensor is an optical fiber. A number of sensing areas and non-sensing areas are arranged on the optical fiber. Each sensing area comprises a weak grating combination of LPG and FBG. LPG is sensitive to salinity and temperature, and produces power loss with the amplitude related to salinity and temperature for backscattered light. FBG is only sensitive to temperature, and produces power enhancement with the amplitude related to temperature for backscattered light. Single-wavelength pulse laser is input into the optical fiber. A backscattered light signal returned by the optical fiber is detected. The backscattered light signal is demodulated to acquire the sea water temperature and salinity detected by each sensing area. The sea water temperature value and the salinity value of multiple points are measured at the same time. The demodulation step is simple. According to the invention, LPG and FBG are optimized by writing parameters; the loss is low; and cascade long-distance quasi-distributed sea water temperature salinity detection is realized.

A method for detecting an Almost-Blank Subframe (ABS) configuration for an interfering macro cell of a heterogeneous network is implemented in a wireless terminal. For one or more resource blocks in a received signal, a first power metric is calculated as a function of channel response estimates determined for predicted cell-specific (or common) reference signal (CRS) resource element locations in a plurality of symbols. For the one or more resource blocks in the received signal, a second power metric is calculated as a function of channel response estimates determined for the predicted CRS resource element locations in a single one of the plurality of symbols. A difference between the first and second power metrics is compared to a threshold, and responsive to the comparison a determination is made as to whether the macro cell is operating in a Multicast and Broadcast Single Frequency Network (MBSFN) mode or a non-MBSFN mode.

This invention provides a method and system of automatically collecting and counting the television view rate, characterized in that the method comprises the following steps: a) the data receiving and counting unit 102 in CATV network node 101 will send data collecting open signal to the data burst collecting unit 105 in sampling user through the forward direction chain circuit of the two-way CATV network; b) the data collecting burst unit 105 will send the receive data to the receiving and counting unit 102 through the return chain circuit; c) the data receiving and counting unit will dressing, storing, analyzing and counting the returned data; d) getting the estimated value of view rate of the area covered by that network node. If gathering and processing the data of all network nodes, it can count the estimated view rate of bigger range.

The receiver (1) picks up low rate FSK radio frequency signals. This receiver includes an antenna (2) for receiving FSK radio frequency signals, a low noise amplifier (3) connected to the antenna, a local oscillator (7) for supplying oscillating signals (LO), a phase shift circuit (16) for performing a 0° to 90° phase shift, and vice versa, in the oscillating signals (LO) or the incoming FSK radio frequency signals in each semi-period of a phase switching cycle (1/fs). The phase shift circuit alternately and successively generates in-phase and quadrature oscillating signals, or in-phase and quadrature incoming FSK radio frequency signals. The receiver includes a single mixer (4) for mixing the oscillating signals successively with the incoming FSK radio frequency signals, so as to generate alternately intermediate in-phase and quadrature baseband signals (INT) as a function of the phase shift circuit. The receiver further includes a low-pass filter (8) for filtering the intermediate in-phase and quadrature signals, and a demodulation stage (20) for demodulating the data (D_OUT) from the filtered intermediate signals. The receiver is arranged such that the phase shift circuit (16) is switched by a phase selection signal (SEL) to a phase switching cycle frequency (fs) which is lower than the frequency deviation (Δf) of the modulated data in the FSK radio frequency signals and higher than the data rate frequency. Magic circuits (14, 15) in the demodulation stage reconstruct the intermediate signals during each switch operation for continuous demodulation in the demodulator (12).

A sensor apparatus combines an optical sensor in which acceleration, acoustic velocity, or displacement (vibration) causes a corresponding shift in the center wavelength of the sensor output, coupled to a high speed interferometric interrogator, through an unbalanced fiber interferometer. The unbalanced interferometer functions to translate optical wavelength shift into phase shift, which is easily demodulated by the interrogator.

The present invention provides a micro-machine magnetic field senor and an application thereof. The sensor at least comprises a resonance oscillator and an insulation layer and at least one layer of metal coil arranged on the surface of the resonance oscillator in order. An S-shaped folding beam is employed to realize the connection of an elastic beam and an anchor to ensure that the resonance oscillator is moved along the direction perpendicular to the resonance oscillator when the resonance oscillator is subjected to resonance and greatly improve the variation of a resonance beam in the enclosed area unit time compared to a square ring formed by a general dual-end fixed support beam so as to increase the variation of the magnetic flux in the metal coil and the sensitivity of a magnetic field. Besides, a grounding aluminium layer is added in the insulation layer of the metal coil to effectively avoid the problem that the signals of the resonance oscillator are coupled to the metal coil. The micro-machine magnetic field senor and the application thereof are simple in structure and reduce the loss of a device with no need for current communication on the metal coil; and moreover, the size of the magnetic field is measured through measurement of the induced electromotive force at two ends of the metal coil, and therefore the influence of the temperature is small.

Certain embodiments of the present invention provides a system and method for SAP FM demodulation. The system includes a bandpass filter for isolating the SAP signal, a Hilbert filter to produce a copy of the SAP signal phase shifted by 90 degrees, an FM demodulator for demodulating the SAP signal using the phase shifted SAP signal and a delayed SAP signal, and a lowpass filter to eliminate noise from the FM demodulated SAP signal. The system may also include an automatic gain control for normalizing amplitude of FM demodulator input signals. The digital FM demodulator uses a simplified approximation using non-unity delay for simplified demodulation of frequency modulated signals.

The invention discloses a three-dimensional shape measurement method. The method comprises steps: based on a distributed measurement system, a stress value of an optical fiber core with an eccentric fiber core is measured; a vector and an intermediate variable are acquired; a bent angle of each point in an optical fiber link is acquired; a torsion function is acquired; a curvature function is acquired; a tangent vector is acquired; and a curve in three-dimensional space is acquired. The fact that a fiber Bragg grating is inscribed in a multi-core optical fiber in the prior art is not needed, the distributed sensor based on the method of the invention is convenient to make and convenient to demodulate, the making process and the steps for the sensor are simplified, and the implementing cost is reduced.

The invention discloses a great-angle tilted fiber bragg grating mechanical vibration sensing array and a great-angle tilted fiber bragg grating mechanical vibration sensing system. The great-angle tilted fiber bragg grating mechanical vibration sensing array comprises an optical fiber core, and is characterized in that: the front section of the optical fiber core is provided with a 45-degree tilted fiber bragg grating, and the 45-degree tilted fiber bragg grating serves as a polarizer of a great-angle tilted fiber bragg grating vibration sensor; an included angle between tilted grating stripes of the tilted fiber bragg grating and an optical fiber cross section is 45 degrees; the middle section of the optical fiber core is provided with N great-angle tilted fiber bragg gratings, and N is a natural number greater than or equal to 1; grating stripes of the N great-angle tilted fiber bragg gratings are parallel to one another, and an included angle between the tilted grating stripes of each great-angle tilted fiber bragg grating and the optical fiber cross section ranges from 79 to 84 degrees; and the outer surface of an optical fiber cladding corresponding to each great-angle tilted fiber bragg grating is provided with an elastic membrane. The great-angle tilted fiber bragg grating mechanical vibration sensing array and the great-angle tilted fiber bragg grating mechanical vibration sensing system can be widely used in the fields of optical fiber perimeter and structural safety monitoring, landslide early warning and the like.

The invention discloses a long distance passive liquid level sensor based on distributed fibers, for solving the problem that a current fiber liquid level sensor has low accuracy and low stability. The long distance passive liquid level sensor based on distributed fibers comprises a light source, a comparison circuit, a wavelength division multiplexing device array formed by N wavelength division multiplexing devices, and a fiber array formed by N fibers, wherein pumping arms of the N wavelength division multiplexing devices are connected with the light source; signal arms of the N wavelength division multiplexing devices access the comparison circuit; beam combination arms of the N wavelength division multiplexing devices are correspondingly connected with head ends of the N fibers one to one; tail ends of the N fibers are measuring ends; the vertical distance between the end surfaces of the tail ends of the two adjacent fibers is x, and x is the measuring accuracy to be achieved. The long distance passive liquid level sensor based on distributed fibers can determine the liquid level position according to the abrupt change position of luminous intensity, being similar to digital detection, wherein the measuring accuracy is mainly decided by the distributed spacing of the fibers. Besides, the long distance passive liquid level sensor based on distributed fibers can eliminate the influence of energy shaking of light source and external disturbance on measurement, is slightly influenced by environment, and has high measuring accuracy and high stability.