252 results about "Binary modulation" patented technology

The invention discloses a multi-dimensional encryption anti-counterfeiting printing technology based on binary signals. According to the anti-counterfeiting printing technology, two-dimensional encryption anti-counterfeiting information can be generated into binary modulation signals by encryption and channel coding, and the anti-counterfeiting information is orderly changed in an amplitude modulation screening form and embedded into a whole page in a modulation mode of a circulating table look-up method, so that the anti-counterfeiting information can be identified from a random fragment during presswork identification. The technology has strong fragment resistance, can resist illegal copying behaviors based on a camera, a scanner, an electronic document and the like more effectively, and can be widely applied in the anti-counterfeiting field of presswork.

The invention discloses an encrypting anti-counterfeiting printing technology for modulating the shapes of amplitude modulation dots of a printed work through a binary-system encrypting signal. In the anti-counterfeiting printing technology, anti-counterfeiting information is subjected to encryption and channel coding to form a binary-system modulating signal and the anti-counterfeiting information is embedded into a whole page by sequentially changing the shapes of the amplitude modulation dots in a circulating table lookup modulation way. During recognition of the printed work, the anti-counterfeiting information can be recognized from any fragment, so the anti-breakage performance is high, the illegal replication based on a camera, a scanner, an electronic document and the like can be more effectively prevented and the technology can be extensively applied to the field of printed work anti-counterfeiting.

A method for generating a global positioning signal from a space based craft including the steps of generating a plurality of binary modulating signals using a waveform generator; separately modulating an in-phase component of a desired carrier of the global positioning signal to be generated with at least a first binary, modulating signal selected from the plurality to generate at least one corresponding in-phase modulated signal component; separately modulating a quadrature component of the carrier with at least a second binary modulating signal selected from the plurality to generate at least one corresponding quadrature modulated signal component; and, combining the at least one in-phase modulated signal component and the at least one quadrature modulated signal component to generate the global positioning signal; wherein the global positioning signal has a constant envelope.

The invention relates to a method and system for rapidly three-dimensionally microimaging a large sample. The method comprises the following steps: 1, a sample is embedded in a sample block and is fixed on a precise three-dimensional electric translation platform; 2, a digital micro mirror array works in a binary modulation mode, and is used for carrying out binary modulation on illuminating light to form structure striations, a structured light microscope collects an image of the surface layer of the sample within a depth of 1-100micrometers; 3, completing the imaging of the inner surface layer of an imaging region, removing an imaged part of the surface layer of the sample block by using a diamond or hard alloy tool; and 4, repeating the steps 2 and 3 until a data acquiring task is completed. According to the invention, the digital micro mirror array works in the binary modulation mode, the imaging speed is effectively increased; and with an exposure synchronization method of the digital micro mirror array and a surface array camera, the sample can be irradiated by exciting light only when a surface array camera is exposed, the exposure quantity of the sample is further reduced, and the negative effects of a light bleaching effect to imaging is avoided.

Disclosed by way of exemplary embodiments, a 40/50/10 Gb/s Optical Transceivers/transponders which use opto-electronic components at data rates collectively that are lower than or equal to half the data rate , using two optical duobinary carriers. More specifically, the exemplary embodiments of the disclosed optical transceivers/transponders relate to a 43 Gb/s 300 pin MSA and a 43˜56 Gb/s CFP MSA module, both include a two-carrier optical transceiver and the appropriate hardware architecture and MSA standard interfaces. The two-carrier optical transceiver is composed of a pair of 10 Gb/s optical transmitters, each using band-limited duobinary modulation at 20˜28 Gb/s. The wavelength channel spacing can be as little as 19˜25 GHz. The same principle is applied to a 100 Gb/s CFP module, which is composed of four tunable 10 Gb/s optical transmitters, with the channel spacing between optical carriers up to a few nanometers.

A simple and effective all-optical system, producing a multilevel coded optical signal based on the M-ASK technology and by the minimized equipment. The novel all-optical modulation technique for optical M-ASK generation is based on nonlinear interaction between optical signals, say between N 2-ASK modulated pump signals having extinction ratio ER₁ and a single 2-ASK modulated optical probe signal having extinction ratio ER₂. According to the invention, a 4-ASK optical signal can be obtained using just a single binary modulated pump optical signal and a single binary modulated probe optical signal.

A radar system in which Coded Aperture Radar processing is performed on received radar signals reflected by one or more objects in a field of view which reflect a transmitted signal which covers a field of view with K sweeps and each sweep including Q frequency changes. For Type II CAR, the transmitted signal also includes N modulated codes per frequency step. The received radar signals are modulated by a plurality of binary modulators the results of which are applied to a mixer. The output of the mixer, for one acquisition results in a set of Q·K (for Type I CAR) or Q·K·N (for Type II CAR) complex data samples, is distributed among a number of digital channels, each corresponding to a desired beam direction. For each channel, the complex digital samples are multiplied, sample by sample, by a complex signal mask that is different for each channel.

The invention relates to a passive optical network comprising an optical exchange linked by at least one optical fiber to at least one line termination device of said network, able to transmit a downlink optical signal phase-modulated in NRZ-DPSK format and to receive an uplink optical signal.

According to the invention, said line termination device comprises means of converting the transmitted downlink optical signal phase-modulated in NRZ-DPSK format into an optical data signal amplitude-modulated in duobinary modulation format and means of generating an uplink optical signal phase-modulated in NRZ-DPSK format from the downlink optical signal phase-modulated in NRZ-DPSK format. The optical exchange is able to convert the uplink optical signal phase-modulated in NRZ-DPSK format into an optical data signal amplitude-modulated in duobinary modulation format.

An optical transmission apparatus using duobinary modulation adapted to an optical communication system using dense wavelength division multiplexing (DWDM) is disclosed. The duo-binary optical transmission apparatus includes an electro-absorption modulated laser (EML) for performing a light intensity modulation operation based on an electrical data signal and producing a modulated optical signal, the EML having a light source for outputting carriers and a modulator for performing the light intensity modulation operation, a precoder for inputting an inverted signal of the electrical data signal and encoding it to an encoded signal, and a modulator for performing a phase modulation of the optical signal modulated by the EML and outputting a duo-binary optical signal, according to the encoded signal.

The invention discloses a Chirp signal-based signal transmitting and receiving method for ultra wide band secret communication, which relates to a signal transmitting and receiving method for the ultra wide band secret communication and solves the problem that a conventional communication method cannot ensure the security of communication in the communication. The Chirp signal-based signal transmitting and receiving method for the ultra wide band secret communication comprises a transmitting process and a receiving process, wherein the transmitting process comprises the following steps: mapping digital information output by an information source to obtain binary modulation information, and sending and emitting a pulse signal of a current time according to a set parameter by a modulation Chirp signal generator; and the receiving process comprises the step that: in a system set time, a receiving end samples the ith modulation signal, performs fractional Fourier transform and parameter adjustment on the ith modulation signal, adds and synthesizes the signals to obtain a synthesized signal and demodulates and outputs the synthesized signal. The method is suitable for the process of the ultra wide band secret communication.

The invention provides a method for demodulating uniform binary modulation signals, which includes a narrowband digital band pass filter and a threshold detector; the narrowband digital band pass filter is composed of one or more IIR digit filter basic links that are concatenated together, each basic link utilizes a pair of zero point and an extreme point that have very approximate resonant frequency to generate a zero group delay point on a phase-frequency characteristic curve, which can indicate the modulation characteristics of the signal while removing the noise; the threshold detector adjudicates the amplitude jump corresponding to the signal modulation characteristics at the output end of the narrowband digital band pass filter directly by a given or self-adjusted level value so as to demodulate the binary modulation information of the uniform binary modulation signals.

The invention discloses sample cell temperature controllable spectrophotometer. The wide spectrum light beam emitted from the light source is changed into one light wavelength light beam through binary modulation plate, monochromator, filter, and polarizer, and changed into detecting light shoot into photoelectric sensor through heating device. The heating device is fixed on rotatable specimen stage. The specimen stage is connected to detector tumbler by rotating shaft. The photoelectric sensor is at the other side of the tumbler. The tumbler is drove by stepper motor. Photometer is controlled by controller. The invention solves the problem that spectrophotometer cannot measure optics sample transmission reflectance characteristics at a certain constancy of temperature; or the transmission reflectance characteristics change with the temperature. It can apply in optical element with high using temperature demand, such as optical thin film transmission reflectance ratio measuring.

A conversion method for converting a unipolar voltage data stream into a carrier-suppressed return-to-zero (CSRZ) optical data stream includes modulating a continuous optical wave with an encoded nonreturn-to-zero (NRZ) voltage data stream for providing a CSRZ optical data stream of full-width at half-maximum (FWHM) pulse width less than one-half of the transition time of the encoded nonreturn-to-zero (NRZ) voltage data stream between logical states for a reduced pulse width. The modulating circuit is either a duobinary modulator driven with a swing of ±2V_π or an optical time domain multiplexed plurality of nonreturn-to-zero (NRZ) modulators with phase shifting and differential encoding.

Duobinary and NRZ modulation of an X-Gb/s optical signal is achieved with a lumped element InP Mach-Zehnder device configured to operate at X/k-Gb/s where k>1 and arranged in a push-pull configuration.

A method and apparatus is provided for controlling the bias point of a Mach-Zehnder modulator. The method begins by applying a dither signal to a DC bias that is applied to a Mach-Zehnder modulator. A component of an optical output signal provided by the Mach-Zehnder modulator that is synchronous with the dither signal is detected. The dither signal is adjusted to maintain the detected component of the optical output signal at a substantially constant value.

A variation on conventional DPSK binary modulation schemes is provided. One modulation scheme uses 3π/8 differential binary phase shift keying (3π/8-DBPSK) where one symbol is transmitted by phase change of 3π/8 radians and the other symbol is transmitted by phase change of −5π/8 radians. Alternatively, this can be thought of as adding a constant 3π/8 radians to the symbol angle for every bit modulated by conventional DBPSK. In another example, assume a first and second symbols, k−1 and k, respectively, are sent. Where k is the same symbol as k−1, a phase rotation of 3π/8 radians from the k^th symbol is used to represent the symbol at k−1; and where the k−1 symbol is the opposite of the k^th symbol, its rotation 11π/8 radians from the k^th symbol. Other modulation schemes using other phase rotations can be provided.

A circuit includes: a portion for performing a logical operation based on a binary modulated signal and a cyclic signal; serial-to-parallel converter for sampling a operation output for parallel output; correlation filter having multiple digital filters for allowing the parallel signal values to pass therethrough; maximum difference detector for detecting a maximum difference in a period during which a difference between the maximum and minimum output signal values from digital filters is greater than a threshold; timing detector for detecting the inversion timing of each output signal value; and decision timing exterminating portion for determining decision timing based on the maximum difference and the detected inversion timing.