A transmitter and corresponding method for transmitting an OFDM signal in a communications channel, including a plurality of base-band OFDM modulators, each for modulating a respective data signal onto a plurality of orthogonal sub-carriers and outputting a respective sub-channel OFDM signal; and a fast convolution filter and up-converter for applying fast convolution filtering and digital up-conversion to the sub-channel OFDM signals to output a combined OFDM signal that includes each of the sub-channel OFDM signals, the fast convolution and up-converter filtering each of the sub-channel OFDM signals and frequency shifting all of the sub-channel signals to respective designated frequencies within the combined OFDM signal. A corresponding receiver is also provided.
A radio frequency (RF) transmitter includes a basebandprocessing module, an up conversion module, a power amplifier module, and an antenna assembly. The basebandprocessing module is coupled to convert outbound data into a first outbound symbol stream and a second outbound symbol stream and to generate an adjust signal. The up conversion module is coupled to convert the first outbound symbol stream into a first up converted signal and to convert the second outbound symbol stream into a second up converted signal. The power amplifier module is coupled to amplify the first and second up converted signals to produce first and second outbound RF signals. The antenna assembly is coupled to transmit the first and second outbound RF signals, wherein the antenna assembly adjusts at least one of amplitude and phase of at least one of the first and second outbound RF signals based on the adjust signal.
A system and a method of a transparent color image display utilizing fluorescence conversion (FC) of nano-particles and molecules are disclosed. In one preferred embodiment, a color image display system consists of a light source equipped with two-dimensional scanning hardware and a FC display screen board. The FC display screen board consists of a transparent fluorescence display layer, a wavelength filtering coating, and an absorption substrate. In another preferred embodiment, two mechanisms of light excitation are utilized. One of the excitation mechanisms is up-conversion where excitation light wavelength is longer than fluorescencewavelength. The second mechanism is down-conversion where excitation wavelength is shorter than fluorescence wavelength. A host of preferred fluorescence materials for the FC screen are also disclosed. These materials fall into four categories: inorganic nanometer sized phosphors; organic molecules and dyes; semiconductor based nano particles; and organometallic molecules. These molecules or nano-particles are incorporated in the screen in such a way that allows the visible transparency of the screen. Additionally, a preferred fast light scanningsystem is disclosed. The preferred scanning system consists of dual-axes acousto-optic light deflector, signalprocessing and control circuits equipped with a close-loop image feedback to maintain position accuracy and pointing stability of the excitation beam.
The invention relates to a method and system for wideband digital pre-distortionlinearization, which is used to overcome the influence of memory effect in radio frequency power amplifier, to expand digital pre-distortionlinearization bandwidth, and to improve digital pre-distortionlinearization performance. The method and system can get an in-band pre-distortion signal and an out-of-band pre-distortion signal according to the characteristic parameter of the amplifier; the in-band pre-distortion signal is up-converted and the up-converted signal is added to the out-of-band pre-distortion signal, which is not up-converted, then the combined signal is inputted to the power amplifier as an input signal; a part of the output signal from the power amplifier, serving as a feedback signal, can be compared with the original input signal, and the characteristic parameter of the amplifier for generating the in-band pre-distortion signal and the out-of-band pre-distortion signal is adaptively regulated according to the comparison result, so that the waveform of time domain or the frequency domain of the feedback signal can be close to that of the original input signal as much as possible.
According to one exemplary embodiment, a voltage up-conversion circuit includes a modulated voltage generator circuit, where the modulated voltage generator circuit is configured to receive an input voltage and generate a modulated voltage, and where the modulated voltage generator circuit includes at least one transistor. The voltage up-conversion circuit further includes a switching circuit coupled to the modulated voltage generator circuit, where the switching circuit is configured to couple the modulated voltage to a load capacitor when the modulated voltage is at a high level and decouple the modulated voltage to the load capacitor when the modulated voltage is at a low level. In the voltage up-conversion circuit, the load capacitor reaches a voltage greater a breakdown voltage of the at least one transistor in the modulated voltage generator circuit. The breakdown voltage can be a reliability breakdown voltage.
Methods and compositions for using an up-conversion phosphor as an emitting material in a reflective displays and Polymer compositions for display mediums, and blue green red (BRG) display mediums. Roles of the pumping duration and character on the temperature and the efficiency of the up-conversion process in (Ytterbium, Erbium or Thulium) co-doped fluoride crystals are set forth. Methods, compositions and display mediums for using up-conversion phosphors in both reflective and transmissive displays in which the substrate and pixel shapes are designed to maximally remove heat deposited in the emitting material and thereby improve the efficiency of up conversion.
A method and apparatus compensate for a non-linear characteristic of a wideband power amplifier in a transmitter for a communication system, which has the wideband power amplifier for amplifying a digital inputsignal. The method involves the steps of (a) generating an address based on the digital inputsignal, reading a distortion control value corresponding to the address from a look-up table, and applying the read distortion control value to the digital inputsignal to predistort the digital input signal; (b) frequency up-converting the predistorted signal and amplifying the frequency up-converted signal; (c) frequency down-converting the amplified signal and compensating for a delay of the frequency down-converted signal; and (d) updating a predetermined distortion control value in the look-up table to compensate for an error value generated in the power amplifier and an analog path occurring in steps (b) and (c) based on the compensated signal.
An Encoder Assisted Frame RateUp Conversion (EA-FRUC) system that utilizes various motion models, such as affine models, in addition to video coding and pre-processing operations at the video encoder to exploit the FRUC processing that will occur in the decoder in order to improve the modeling of moving objects, compression efficiency and reconstructed video quality. Furthermore, objects are identified in a way that reduces the amount of information necessary for encoding to render the objects on the decoder device.
The invention discloses a modulation mode identification system and method based on a convolutional neural network, which solve the problems of complex feature extraction steps and low identificationrate under a low signal-to-noise ratio in the prior art. The simple feature in the identification system is constructed as a simple feature using a co-directional component and a quadrature componentof a basebandsignal as signals, and the simple feature is sent to a convolutional neural network module for identification. The identification method comprises the steps of: modulating a transmittedsignal and performing pulse shaping; performing up-conversion on the transmitted signal and then transmitting the transmitted signal through an additive white Gaussian noise channel; performing pre-processing first by a receiving end to obtain the co-directional component r(t) of the analyzed signal; constructing the simple feature, i.e., constructing the co-directional component r(t) and the quadrature component of the analyzed signal into a two-dimensional matrix; performing feature learning and classification by the convolutional neural network; and sending a modulation method to a demodulation end to obtain a demodulated signal. The method is low in feature design complexity, avoids explicit feature extraction, has high classification correctness, and can be applied to communication systems having high recognition performance requirements.
The invention discloses a vehicle-mounted millimeter-wave radar moving target recognizer. The vehicle-mounted millimeter-wave radar moving target recognizer is characterized in that the recognizer is a frequency synthesizer; a frequency agilitycontinuous signal is modulated into a pulse signal and then is processed into a millimeter-wave signal by up-conversion; after being amplified by a power amplifier, the millimeter-wave signal is transmitted out; an antenna receives a radarecho signal back to a circulator and then the signal is transmitted into a frequency mixer; a high-frequency echo pulse and constant-amplitude high-frequency voltage generated by a high-stability local oscillator are mixed and the signal is reduced to a middle frequency and then is processed by a middle-frequency amplifier; the middle-frequency signal is directly sampled by an A / D (Analogue / Digital) conversion module; after being sampled, echo signals of a whole pulse string are stored into a storage unit; and information of targets, such as quantity, speed and direction, is measured by a signal processing unit and then is transmitted to an alarm executing unit. With the adoption of the structure, the vehicle-mounted millimeter-wave radar moving target recognizer has the advantages that 1 the distance measuring precision and the angle measuring precision of a moving target are improved; and 2 excessive hardware does not need to be added and the production cost is lower.
The invention relates to an intelligent insomnia therapeutic instrument, aiming at providing a therapeutic instrument which can induce and regulate potential action of the sleep center of a patient so as to accelerate the falling asleep speed of the patient and improve the sleep quality or realize a natural timing awaking function. The technical proposal is as follows: the instrument comprises a signal output module generating time varying magnetic fields, a bipolar electrode brain wave acquiring module acquiring real-time brain waves of the patient and a main controller obtaining the brain waves and carrying out down-conversion or up-conversion, wherein the signal output module converts digital brain signals output by the main controller into analogue signals which are amplified so as to drive a magnetic field generator to generate time varying magnetic fields used for treating.
The embodiment of the invention discloses an active antenna, a base station, a method for refreshing amplitude and phases and a signalprocessing method, which are invented for solving the problems of complex structure and less unreliability of a phase shifting network. The active antenna or the base station comprises an antenna oscillator array, a transceiver unit array, a digital processing unit and a transceiving calibration unit. When receiving signals, a transceiver unit modulates radio frequency signals of an antenna oscillator into IQ analog signals by down-conversion, and outputs the IQ analog signals to the digital processing unit; and the digital processing unit converts the IQ analog signals after down-conversion modulation into IQ digital signals, and forms digital beams of the IQ digital signals according to the transceiving calibration unit. When transmitting the signals, the transceiver unit modulates the IQ analog signals of the digital processing unit into the radio frequency signals by up-conversion, and outputs the radio frequency signals to the antenna oscillator; and the digital processing unit converts signals of a base band unit into IQ digital signals by serial / parallel conversion, and forms digital beams of the IQ digital signals according to the transceiving calibration unit.
A linear high powered integrated circuittransmitter includes an up-conversion module, a plurality of power amplifiers, balanced integrated circuitcoupling, and a combining circuit. The up-conversion module is operably coupled to produce a differential up-converted signal by mixing one or more local oscillations with a low intermediate frequency (IF) signal. The balanced integrated circuitcoupling couples the plurality of power amplifiers to the up-conversion module such that the power amplifiers amplify the up-converted signal to produce a plurality of amplified radio frequency (RF) signals. The combining circuit is operably coupled to combine the plurality of amplified RF signals to produce a transmit RF signal.
A broadband integrated receiver for receiving input signals and outputting composite video and audio signals is disclosed. The receiver employs an up-conversion mixer and a down-conversion mixer in series to produce an intermediate signal. An intermediate filter between the mixers performs coarse channel selection. The down-conversion mixer may be an image rejection mixer to provide additional filtering.
The method comprises: after sequentially making RS coding and byte interlace, LDPC coding, bit interlace and constellation mapping for the upper layer data, the acquired data symbol, discrete pilot frequency and the continuous polite frequency are multiply connected to form OFDM polite frequency and make scrambling; generating OFDM symbol through IFFT transformation, and after forming time slot through inserting frame head, they are connected to form signal frame of physical layer; after making low pass filter and quadrature up-conversion for the physical layersignal frame, they are sent out. The invention can provide radio broadcast such as audio, video and multicast for mobile, fixed and portable receiver. The system thereof uses micro wave and large-scale IC technology. The method adopts OFDM of LDPC solution.
The invention discloses a phased array digital multi-beam generator for electronic reconnaissance, for the high resolution direction measurement having strong and weak signals or coherent multi signals, and forming the multi-target signal into anti-interference digital multi-beam to form a multi-beam process: first, in a data acquisition pretreatment board, an AD samples intermediate frequency analogue real signals output by each array antenna receiver, a DPS and a FPGA chip are cooperated to complete quadrate sampling and amplitude phase error correction; the intermediate frequency analogue actual signals are converted into a baseband digital complex signal and the amplitude phase error between the multi channels is corrected; a LVDS channel transmits the baseband digital complex signal to a signalprocessing board, the DPS completes the high resolution direction measurement having strong and weak signals or coherent multi signals and calculates the weight value group formed by the adaptive beam; the weight value group is added into the wave beam in the signal processing board FPGA to form a network; completing forming anti-interference digital multi-beam of the multi-target signal; an up frequency converter converts the output of the anti-interference digital multi-beam into needed intermediate frequency analogue signal.
An apparatus and method applicable for generating ultravioletlaser light having a wavelength in the 200-nm range and / or 250-nm range; in some embodiments, using a single fiberlaser pump source (in some embodiments, a pulsed source). In some embodiments, the invention provides methods of generating 250-nm or 200-nm photons using a mode-locked 1000-nm fiberlaser and efficient 4th / 5th harmonic frequency up-conversion. In other embodiments, the invention uses continuous wave (cw) single-frequency fiber lasers and external resonant frequency conversion. In still other embodiments, the invention uses cw single-frequency optically-pumped semiconductor lasers (OPSLs) and electrically driven vertical-cavity surface-emitting lasers (VCSELs) and externally resonant frequency conversion. All of these produce both of the ultraviolet wavelengths of interest
An apparatus for a wireless transmission of high data rate signals such as received from an optical interface including gigabitfiber channel or a sonet. The architecture combines direct detection of the optical signal with clock and data recovery circuit and a differential signalencoder which is preferably a differential quadrature phase shift encoder and modulator pair. A millimeter wave, local oscillator and up conversion chain converts the optical input signal to a microwave carrier. In the opposite direction, the down converted signal is non-coherently phase detected and fed to a pair of synchronized clock and data recovery circuits to recover I and Q channel signals. These recovered signals are then combined prior to re-timing before they are fed back to the optical transceiver.
A method and a micro power generator for generating electrical power from low frequency, vibrational energy includes a frequency up-conversion process. The generator is preferably an electromagnetic, vibration-to-electrical power generator which can efficiently scavenge energy from low frequency external vibrations. The generator up-converts low frequency environmental vibrations to a much higher frequency through a mechanical frequency up-converter, and hence provides efficient energy conversion even at low frequencies. This mechanical frequency up-conversion process can be realized in a number of ways. A magnetic method is described as an example. After frequency up-conversion, voltage is induced on coils mounted on resonators by electromagnetic induction. Due to the movement of the coils on their respective resonating cantilevers with respect to the magnet, voltage is generated on the coils and energy conversion is realized.