51results about How to "Reduced dynamic range requirements" patented technology

An adapter allows the interconnection of a sensor originating from one manufacturer to be coupled with conventionally incompatible monitors originating from other manufacturers to form a properly functioning pulse oximetry system. The adapter matches a sensor driver in a monitor to the current requirements and light source configuration of a sensor. The adapter also matches a sensor's light detector signal level to the dynamic range requirements of a monitor preamplifier. Further, the adapter provides compatible sensor calibration, sensor type and security information to a monitor. The adapter may have a self-contained power source or it may derive power from the monitor, allowing both passive and active adapter components. The adapter is particular suited as an adapter cable, replacing a conventional patient cable or sensor cable as the interconnection between a sensor to a monitor in a pulse oximetry system.

A method is provided for controlling EGR flow in turbocharged engine. The method comprises operating a low-pressure exhaust gas recirculation (LP-EGR) system at a fixed EGR percentage rate of fresh airflow from mid-load down to a minimum engine load, even as load changes. In this way, errors in the delivered LP-EGR rate during transient conditions may be alleviated by providing a fixed EGR percentage of fresh airflow at all engine loads within a fixed mode range.

The invention discloses a co-channel full-duplex system based on MPPSK modulation. After the system isolates receiving and sending signals at the radio-frequency head normally, cancellation conducted on leakage self-interference signals is finished on a digital baseband; the cancellation method is conducted after conducting shock filter on MPPSK receiving and sending aliasing signals, extracting and multiplying by coherent carrier, band-pass filtering and digitizing, the result of initial channels of all self-interference channels between the output end of a modulator and a receiver ADC is estimated before formal communication, self-interference offset signals are rebuilt by the adoption of the estimated result, further residual errors are filtered out with the combination of methods of coding rate filtering and double matched filtering of a method of shock filtering-multiplying by the coherent carrier-band-pass filtering-coherent demodulation, and MPPSK receiving signals are demodulated reliably. The co-channel full-duplex system based on MPPSK modulation is free of radio-frequency self-interference cancellation, has low requirements for the dynamic range and sampling rate of the ADC, has high isolation degree for the self-interference signals, and is simple in structure, low in complexity, high in spectrum efficiency and good in demodulation performance.

The use of wideband or software defined radio is attractive in terms of cost reduction since it allows re-use of base stations for different transmission modes. However, wideband radio also introduces the problem of how to deal with high level interfering signals. Presently, such signals saturate parts of the receive circuit—typically the ADC. By detecting interference and determining its frequency, it is possible to tune a bandpass or bandpass with notch filter, to take the interfering signal out of the reception band of the receiver thereby taking the ADC out of saturation whilst retaining the ability to resolve low level signals.

A method and apparatus for reducing crosstalk in a multi-channel communication system is disclosed. In one embodiment, outgoing signals in a multi-channel environment are manipulated into a transform domain, such as the frequency domain. Thereafter, the signals may be combined and modified based on a weighting variable to create a cancellation signal. Combined processing greatly reduces system complexity and increases processing speed. After processing in the transform domain, the cancellation signal undergoes further processing to return the cancellation signal into the time domain. The cancellation signal may then be combined with received signals to cancel crosstalk or echo. A method and apparatus for crosstalk cancellation in the analog domain and digital domain is also disclosed. Cancellation at least partially in the analog domain reduces the dynamic range requirements for digital to analog converters within the front-end processing system of a receiver and thereby reducing clipping and increasing operating speed.

In magnetic resonance data acquisition, decoupling between the transmit and receive coils is achieved by using a transmit array system wherein induced currents from the transmit coils cancel each other, resulting in a total of zero current in the receive coil. Forward and reversed polarized transmit coil pairs are set to cancel the individual currents of each other, or of a receive coil. Linearly polarized fields can also be used to effect the decoupling. The decoupling allows the magnetic resonance data acquisition system to be operated for concurrent excitation of the nuclear spins and reception of the resulting magnetic resonance signals.

A method and apparatus for reducing crosstalk in a multi-channel communication system is disclosed. In one embodiment, outgoing signals in a multi-channel environment are manipulated into a transform domain, such as the frequency domain. Thereafter, the signals may be combined and modified based on a weighting variable to create a cancellation signal. Combined processing greatly reduces system complexity and increases processing speed. After processing in the transform domain, the cancellation signal undergoes further processing to return the cancellation signal into the time domain. The cancellation signal may then be combined with received signals to cancel crosstalk or echo. A method and apparatus for crosstalk cancellation in the analog domain and digital domain is also disclosed. Cancellation at least partially in the analog domain reduces the dynamic range requirements for digital to analog converters within the front-end processing system of a receiver and thereby reducing clipping and increasing operating speed.

A method and apparatus for reducing crosstalk in a multi-channel communication system is disclosed. In one embodiment, outgoing signals in a multi-channel environment are manipulated into a transform domain, such as the frequency domain. Thereafter, the signals may be combined and modified based on a weighting variable to create a cancellation signal. Combined processing greatly reduces system complexity and increases processing speed. After processing in the transform domain, the cancellation signal undergoes further processing to return the cancellation signal into the time domain. The cancellation signal may then be combined with received signals to cancel crosstalk or echo. A method and apparatus for crosstalk cancellation in the analog domain and digital domain are also disclosed. Cancellation at least partially in the analog domain reduces the dynamic range requirements for digital to analog converters within the front-end processing system of a receiver and thereby reduces clipping and increases operating speed.

A flat panel antenna used at a wall in a through-the-wall CW radar application is spaced from the wall by a half wavelength to eliminate the effects of energy reflected by the wall back to the antenna. In one embodiment, a ½-wavelength dielectric absorbing material insert is placed adjacent the flat panel antenna, which allows the flat panel antenna to be pressed against the wall for antenna stabilization, with the index of refraction of the material desirably being 3.

The invention discloses a signal feedback loop and a method for predistorter, and power amplification equipment. The signal feedback loop comprises: a down converter for converting feedback signals downward into baseband signals or intermediate frequency signals, a first filer for filtering the baseband signals or the intermediate frequency signals to preliminarily inhibit main band signals among the signals, thereby outputting first filtering signals, an analog-to-digital converter for converting first filtering signals into digital signals from analog signals, a second filer for filtering digital signals to further inhibit the main band signals among the signals, thereby outputting second filtering signals, a power calculator for calculating the out-of-band power of the feedback signals according to the second filtering signals; and a coefficient updating controller for updating the coefficient of the predistorter according to the out-of-band power. With the technology scheme of the invention, the dynamic scope requirement of analog-to-digital conversion and the complexity of simulation circuits can be reduced by shifting part of the simulation loop complexity to digital field and utilizing two-level filtering structure.

The invention refers to a method and device for wideband radar, the method comprising: generating a wideband signal (1, 6) with a bandwidth B; copying the wideband signal (1, 6); transmitting the wideband signal (6′); receiving a returned echo signal (11) from the transmitted signal (6′); dividing the copied signal into a number, Nf, of subsequent frequency bands b; manipulating the copied and divided signal into an anticipated signal (10) by adding a number Nd of anticipated delays and a number of ND Doppler stretches to the copied and divided signal for each Nf subsequent frequency band b; dividing the received signal (17) into a number, Nf, of subsequent frequency bands b; correlating corresponding frequency bands in the divided received signal (17) and the anticipated signal (10) giving NdND correlated signals (19) for determining range (R) to a target and velocity (v) of the target.

The invention discloses a method and a device for sending and receiving data in high-sensitivity narrow band wireless communication. The method comprises the steps of treating two continuously reversed linear frequency modulation signal as a synchronous sequence in a front synchronizing head, treating two same complex sine signals as reference symbols in the front synchronizing head, and then forming a frame to be sent tighter with baseband data to be sent through a sending end; modulating the frame to be sent to two in-phase orthographic carriers to form and send a radio frequency sending signal. With the adoption of the method, the angle features can be jointly demodulated without precise frequency offset estimation by the FFT algorithm and the phase; the various conditions and algorithm advantages are combined, so that the single bit calculation quantity is greatly reduced, and moreover, the receiving sensitivity can be improved, and the data transmission distance can be increased.

A reflection type artificial crystal aberration Hartmann instrument mainly comprises a light source, a beam matching system, a standard spherical reflector, a aperture segmentation element, a photoelectric detector and a computer, wherein, a Hartmann wave-front sensor is composed of the aperture segmentation element and the photoelectric detector. Lights emitted by the light source are collimated to be emitted in parallel. The parallel lights pass through an artificial crystal to be measured by a reflector and a spectroscope in sequence. Transmission light waves arrive at the standard spherical reflector which is axially adjusted to lead to the coincidence of the back focus of the artificial crystal to be measured and the spherical center of the standard spherical reflector. Reflected light waves return along an original optical path, pass through the artificial crystal to be measured again, then pass through the spectroscope and the beam matching system in sequence and are segmented and sampled by the aperture segmentation element, and then are focused on the photoelectric detector to form light spot arrays. The acquired light sport data is sent to the computer to be processed, so as to obtain the aberration of the artificial crystal to be measured. The reflection type artificial crystal aberration Hartmann instrument has the advantage of simple and stable structure, which is a convenient, fast and reliable detection tool for the ophthalmology clinical artificial crystal transplantation and processing and the detection of artificial crystals for personalized human eye aberrations correcting.

The invention relates to a method and circuit used to improve high frequency ground wave radar receiver dynamic range. Its features are sea echo signal are divided into two or multi ways; under the control of sequential control circuit, sea approach echo enter analog front end of the receiver after great attenuation; high sea echo directly enter it. This can make receiver have different sensitivity at different detecting distance to realize its word time gain control. The invention not only can hold echo amplitude and phase information, but also can reduce the demand of high frequency ground wave radar receiver dynamic range, corresponding to increase receiver transient dynamic range, and greatly increase phased array radar system action range.

A method and apparatus for reducing crosstalk in a multi-channel communication system is disclosed. In one embodiment, outgoing signals in a multi-channel environment are manipulated into a transform domain, such as the frequency domain. Thereafter, the signals may be combined and modified based on a weighting variable to create a cancellation signal. Combined processing greatly reduces system complexity and increases processing speed. After processing in the transform domain, the cancellation signal undergoes further processing to return the cancellation signal into the time domain. The cancellation signal may then be combined with received signals to cancel crosstalk or echo. A method and apparatus for crosstalk cancellation in the analog domain and digital domain are also disclosed. Cancellation at least partially in the analog domain reduces the dynamic range requirements for digital to analog converters within the front-end processing system of a receiver and thereby reduces clipping and increases operating speed.

The invention discloses a method for transmitting data based on random wave beam shaping, comprising the following steps: a base station terminal generates a beam shaping unitary matrix with constant amplitude for each element and random variable phase position; the base station terminal transmits a plurality of different training symbols to user equipment through the unitary matrix; the user equipment feeds back a received maximum value in a plurality of SINR corresponding to a launching beam and a corresponding number of the launching beam to a base station; and the base station selects the user equipment corresponding to the maximum SINR in the beam for different launching beams for data transmission. The method is applicable to arbitrary number of launching antennae, not only ensures the same amplitude for all the elements of a beam shaping matrix so as to significantly reduce the requirement on a dynamic range of a power amplifier and realize the random beam shaping technology with only one set of phase switcher as well, but also can obtain the same thuoughput as the prior random beam shaping system.

An array detector signal readout channel multiplexing method comprises the steps of dividing array detectors into M groups; each group includes at least two detectors; readout channels are converted into M rows and N columns to readout signals in a rank coding manner, namely the ath row signal and the bth column signal are correspondingly output when the detector at the ath row and the bth column outputs a signal; the signals read out from the row and the column are respectively accessed to different positions of two transmission lines; and determining the source row and column number of the signal according to time difference when the signal reaches two end points of each transmission line, and marking the source detector where the signal is generated according to two groups of time differences of the row and column signals. Application of multiple electronics channels is prevented, and cost and engineering implementation difficulty of an electronics system are reduced; and due to the fact that application of a resistor weighting network is prevented during the channel multiplexing process, the amplitude of the signal cannot be largely changed due to different access points of the signal after multiplexing, and requirements on dynamic ranges of a rear-end readout circuit are reduced.

In magnetic resonance data acquisition, decoupling between the transmit and receive coils is achieved by using a transmit array system wherein induced currents from the transmit coils cancel each other, resulting in a total of zero current in the receive coil. Forward and reversed polarized transmit coil pairs are set to cancel the individual currents of each other, or of a receive coil. Linearly polarized fields can also be used to effect the decoupling. The decoupling allows the magnetic resonance data acquisition system to be operated for concurrent excitation of the nuclear spins and reception of the resulting magnetic resonance signals.

A CMOS integrated circuit for multi-channel neuronal recording with twelve true-differential channels, band separation and digital offset calibration. The recorded signal is separated into 2 bands: a low-frequency, local field potential (LFP); and high-frequency spike data. Digitally programmable gains for the LFP and spike bands are provided. A mixed-signal front-end processor for multi-channel neuronal recording is also described. It receives twelve differential-input channels of implanted recording electrodes. A programmable cutoff HPF blocks DC and low frequency input drift at about 1 Hz. The signals are band-split at about 200 Hz to low-frequency local field potential (LFP) and high-frequency spike data (SPK), which is band limited by a programmable-cutoff LPF. The analog signals are converted into digital form, and streamed out over a serial digital bus at up to 8 Mbps. A special interface system incorporating an embedded CPU core in a programmable logic device accompanied by real-time software allows connectivity to a computer host.

The invention provides a digital signal modulation method of a photon artificial intelligence computing chip. The method comprises the following steps: modulating one or more digital electric signal groups into optical signals, wherein the digital electric signal group comprises a plurality of time sequence signals which are sequentially output in a fixed time period, each time sequence signal hasthe same basic clock and signal time length, a single time sequence signal for transmitting N-bit digital information is provided with 2N-1 basic clocks, the number value of the basic clocks occupiedby a high-level signal or a digital signal '1' in the time sequence signal is the signal value of the time sequence signal and is equal to the value of the transmitted N-bit digital information, andthe time sequence signal is a modulation signal for converting an electric signal into an optical signal. Compared with an existing calculation scheme based on digital-to-analog conversion and analogsignal modulation, a digital-to-analog conversion converter high in cost and power consumption is not needed, the method can be directly connected with digital signals of an electronic chip, and quantization errors generated when the digital signals are subjected to digital-to-analog conversion are avoided.

The device includes at least transmitter receive (T-R) switch, front end sending channel in radio frequency, front end linear low noise amplifier in radio frequency, indication circuit of receiving frequency conversion and receiving field intensity of signal, and baseband control circuit. The method includes steps: baseband control circuit sends the control signal to control T-R switch in radio frequency to set T-R switch in state of receiving channel; linear low noise amplifier magnifies signal from T-R switch, and its output signal is inputted to the said indication circuit; the indication circuit magnifies converted frequency, and outputs intermediate frequency signal, and outputs indication signal; modulating signal, baseband control circuit controls T-R switch by using field intensity indication signal of received signal. If input signal is in radio frequency, baseband control circuit switches channel to sending channel.

The disclosure relates to an error-compensated direct digital modulation device (800), including: a direct digital radio frequency modulator (DDRM) (801), configured to generate a radio frequency (RF) signal (804) based on a modulation of a digital baseband signal (802); an error estimator (803) configured to determine an error signal (806) resulting from a deviation based on the generated RF signal (804) and a representation of the digital baseband signal (802); and an error compensator (805) configured to subtract the error signal (806) from the RF signal (804) to provide an error compensated RF signal (808).

The invention discloses a full duplex system with a high dynamic receiver and a use method thereof. The system comprises a transmitting antenna module, a receiving antenna module, a first shunt, a waveform detection module, a second shunt, an adjustable gain device, a receiving channel module, a first ADC, a second ADC and an envelope restoration module. The output signal of the waveform detection module is an envelope inverse ratio function of an input signal. Gain adjustment can be carried out through an adjustable gain module, compared with the input signal g(t), the output signal j(t) obtained through zooming processing controlled by a gain control signal h(t) has the advantage of remarkably reducing the peak-to-average power ratio, and therefore compared with g(t), the requirement of j(t) for the dynamic range of a receiving channel is remarkably reduced. In ideal conditions, the output signal x(n) of the envelope restoration module is the discretization signal of g(t), it is equivalent to the fact that the receiver completely receives a high dynamic signal, and on the contrary, it is equivalent to the fact that the dynamic state of the receiver is greatly improved.

Disclosed are methods, circuits and systems for image reject filtering in a multi-tap direct sampling mixer (MTDSM) of an IF or RF system. Disclosed is the use of rotating capacitors among the in-phase and quadrature branches of a signal processing system. The exchange of information among the branches of the I and Q channels is used in the implementation of a complex filter. Rotation of a switched capacitor CR between the I and Q channels of the circuit causes a sharing of the charge among the four paths, I+, I-, Q+, Q-, resulting in a direct sampling and a complex filtering arrangement (10). The preferred embodiment of the filter (10) shown can be seen to have four sub-circuits (12, 14, 16, 18), which may be understood as single-pole IIR filters. Embodiments using cascaded multiple stages of the complex filter to provide higher order complex filters are also disclosed.

A method is provided for controlling EGR flow in a turbocharged engine. The method comprises operating a low-pressure exhaust gas recirculation (LP-EGR) system at a fixed EGR percentage rate of fresh airflow from mid-load down to a minimum engine load, even as load changes. In this way, errors in the delivered LP-EGR rate during transient conditions may be alleviated by providing a fixed EGR percentage of fresh airflow at all engine loads within a fixed mode range.

The invention discloses an apparatus and a method for monitoring extra long distance optical cables by using one monitoring wavelength. The method comprises the following steps: 1) checking the output state of an optical receiver R2; 2) if the output state of the optical receiver R2 is that "a test channel is busy", entering the 1) step again; 3) if the output state of the optical receiver R2 is that "the test channel is idle", transmitting a test channel occupation signal; 4) if the output state of the optical receiver R2 is that "the test channel is busy", entering the 1) step again; 5) if the output state of the optical receiver R2 is always that "the test channel is idle", entering an OTDR test state; 6) entering a test termination silence period; and 7) after the test is terminated, receiving an OTDR test command again. The method has the advantages that a time division multiplexing mode is used on both ends to use one monitoring wavelength to monitor the extra long distance optical cables.