50results about How to "Orthogonal" patented technology

The invention discloses an unshielded three-reflector optical system, which can be used in a wide spectral imaging system with wave band from ultraviolet to infrared, and is particularly applicable to a preposed object lens of a spectrum imager. The system consists of a main reflector, a secondary reflector and a third reflector with aperture ratio of 1 / 0.5-1 / 3; the system avoids shielding through inclining elements; a beam path of the system is telecentric beam path in the image side; a principle ray of zero field coverage is spread along links of the vertex of each element; a diaphragm is arranged on the secondary reflector; the secondary reflector is arranged on a focal plane of the third reflector; focal power of the main reflector, the secondary reflector and the third reflector is positive, negative and positive respectively; curvature radiuses of the vertexes of the three reflectors approximately meet the condition of Petzval; and types of the three reflectors are Zernike free surfaces. The system has reasonable residual aberration distribution to greatly improve image quality, and can easily avoid shielding, so that the effective use area of each mirror face is equivalent to an original mirror; and the primary ray of the zero field coverage of the system moves along the links of the vertex of each surface, thereby facilitating the processing, assembly and regulation ofthe system.

The invention relates to a wireless communication technology and discloses a method for generating information of a relay link physical uplink control channel, which comprises the following steps: determining an orthogonal sequence corresponding to a sequence index according to the sequence index; and generating the information carried by the relay link physical uplink control channel (R-PUCCH) according to the determined orthogonal sequence. The invention further discloses a communication device, which comprises a determining unit and a generating unit, wherein the determining unit is used for determining the orthogonal sequence corresponding to the sequence index according to the sequence index; and the generating unit is used for generating the information carried by the R-PUCCH according to the orthogonal sequence determined by the determining unit. According to the scheme of the invention, the corresponding orthogonal sequence is determined according to the sequence index, and the information carried by the R-PUCCH is generated according to the orthogonal sequence, thereby enabling the information to have orthogonality and improving the performances of a relay system.

The emission diversity based on space-time code has space, time and code gains. Wherein, the space-time block code is simple; but, the code efficiency when emission antenna number is larger than 2 opposite to complex signal, and the scheme just fits to quasi-static fading channel. In CDMA system, the scheme uses cycle space-time block decoding method and orthogonal spread-spectrum code to different antennas, simplifies decode same as traditional code, and can improve anti-channel attenuation and system transmission performance.

The invention discloses an anti-noise wireless signal framing modulation method of a multimedia broadcasting single frequency network, relating to a framing modulation scheme with mixture of time domain, frequency domain and space domain. The anti-noise wireless signal framing modulation method of the multimedia broadcasting single frequency network in the invention has the advantages of low peak-to-average power ratio, short synchronization time, noise resistance, controllability of a plurality of services and the like.

A free boundary simulation device for a horizontal vibration experiment belongs to the technical field of mechanical vibration and noise control. In order to solve the problem that the existing experimental device cannot meet the actual needs of the horizontal direction vibration test experiment in the research field of three-way vibration damping and isolation technology, the present invention is The invention describes a free boundary simulation device for a horizontal vibration experiment, wherein the top of the box is provided with an opening, the upper platform assembly and the lower platform assembly are both arranged in the box, and the bottom of the lower platform assembly is fixed on the bottom plate in the box, The bottom of the upper platform assembly is fixed on the platform surface of the lower platform assembly, and the lower platform assembly is connected to a set of opposite inner side walls in the box through the lower leveling unit, and the upper platform assembly is connected to the other in the box through the upper leveling unit. A set of opposing inner side walls are connected. The invention provides new ideas for the research of the three-way vibration damping and isolation technology, provides effective technical support for the popularization and application of new high-precision equipment, and has important theoretical and practical significance.

The invention discloses a noise-resistance framing modulation method for mobile multi-media broadcast signals of a single frequency network, which is a time domain, frequency domain and space domain hybrid framing modulation scheme. The method has the advantages of low peak-to-average power ratio, short synchronous time, robustness, controllability in multiple services and the like.

The invention discloses a digital nuclear magnetic resonance lock signal transmitter receiver set which consists of a lock transmitter, a lock receiver and a lock error output unit. The transmitter receiver set is characterized in that: an FPGA control circuit is connected with a clock distribution circuit and a backboard interface, a digital frequency synthesizer is respectively connected with the clock distribution circuit, a low pass filter and the FPGA control circuit; a digital variable gain amplification circuit is connected with the low pass filter and the FPGA control circuit respectively; the low pass filter is connected with the digital variable gain amplification circuit and a probe respectively; the low pass filter is connected with the probe and a switch respectively; the variable gain amplification circuit is connected with the FPGA control circuit; a frequency mixer is connected with the low pass filter and the variable gain amplification circuit respectively, an IF digital sub-system is connected with the clock distribution circuit, the FPGA control circuit and the low pass filter respectively; and a digital-to-analog converter (DAC) is connected with the FPGA control circuit and a conditioning circuit. The digital nuclear magnetic resonance lock signal transmitter receiver set has the advantages of digital control, good versatility and low cost, and enhance magnetic field stability and anti-interference capability.

The invention discloses a method for extracting the fault signal feature information of an aero-engine rotor system, and the method comprises the steps: collecting a rotor rub-impact vibration signal,and carrying out the FDM decomposition of the collected rotor rub-impact vibration signal to obtain complete rotor rub-impact vibration signal FIBFs components; constructing a Hankel matrix of the rotor rub-impact vibration signal after noise reduction, and drawing a singular value curve of the rotor rub-impact vibration signal after noise reduction; determining a singular value catastrophe point, carrying out the reconstruction of an order number, and carrying out the envelope spectrum analysis, thereby achieving the effective extraction of fault information. According to the invention, themethod achieves the reasonable extraction of the fault feature frequency of a rotor system based on the FDM decomposition and singular value differential spectrum analysis, and achieves the efficientfiltering of the noise signal component in the rub-impact vibration signal, thereby achieving the extraction of the weak fault feature information from the low-frequency strong noise background, and achieving the effective extraction of the fault information.