307 results about "Maximum gain" patented technology

A video input processor is disclosed. The processor includes: an imaging signal-generating portion configured to image a subject and producing first imaging signals containing visible light components and a second imaging signal containing near-infrared light components; a gain adjustment portion configured to adjustably set a maximum gain value according to a relative magnitude between the visible light components and the near-infrared light components and adjust a gain for the first imaging signals at the set maximum gain value; and a noise reduction portion configured to reduce noises in the first imaging signals after the gain has been adjusted.

A system and method for controlling amplification of a signal received by a ZIF radio having a power level within a full power range relative to a minimum noise floor. The ZIF radio includes a ZIF receiver front end, an overload detector, an ADC, a saturation detector, a DC and power estimator, and control logic. The control logic utilized full visibility of the ADC to limit gain of the baseband amplifier to a maximum gain setting sufficient to view the minimum noise floor and to view a received signal having a power level within any of several segments of the power spectrum. The segmentation of the power spectrum is based on an overload condition of the ZIF receiver front end and a saturation condition of the ADC. The control logic further employs limited gain stepping of the baseband amplifier to avoid exceeding a DC budget of the ADC.

A multiple-input multiple-output (MIMO) wireless communication system. A transmitter that includes a plurality of transmit antennas selects one of a spatial multiplexing scheme and a spatial diversity scheme, processes a signal in the selected transmission scheme, and transmits the signal through the plurality of transmit antennas. A receiver that includes a plurality of receive antennas processes a signal in a reception scheme mapped to a transmission scheme of the transmitter. The transmission schemes include a transmission scheme for maximizing diversity gain and a transmission scheme for maximizing spectral efficiency. The MIMO communication system using an adaptive transmission mode switching technique performs switching between MIMO transmission modes using spatial selectivity of a channel, thereby obtaining maximum gain in a signal to noise ratio (SNR) and spectral efficiency according to channel state.

A method of amplification includes amplifying an input signal with a predetermined or user adjustable maximum gain to produce a second signal and compressing the dynamic range of the second signal with an automatic gain control to produce an output signal. The compression ratio of the automatic gain control is greater than one for output signals below a predetermined threshold output signal level and is essentially one for output signals above the predetermined threshold output signal level. The compression ratio may be predetermined or the method may include determining the compression ratio of the automatic gain control. The compression ratio may be determined according to the amplitude of the output signal or according to an input-output curve. The input-output curve my be predetermined and may be selected according to the auditory needs of a listener. Preferably the input-output curve is determined according to the predetermined or user adjustable maximum gain.

A wireless LAN technology for reducing interference between (or among) wireless LAN access points is provided. A wireless LAN access point is provided with a directional antenna, an interference detector detecting interference effected by another wireless LAN access point on the directional antenna, and a direction adjusting mechanism adjusting a maximum gain direction of the directional antenna in response to the detected interference.

An RF tag reading apparatus reads information from RF tags affixed to postal envelopes by a single operation. An article container contains a large number of postal envelopes provided with RF tags. A reader antenna, which is connected to an interrogator via a coaxial cable, is disposed under the article container. Maximum gain directions of the RF tags of the respective postal envelopes are uniformly directed to the reader antenna. The respective postal envelopes contained in the article container are arranged face to face with each other in a direction orthogonal to the maximum directions of the RF tags. Since a maximum gain direction of the reader antenna is oriented toward a base end surface of the article container, the maximum gain directions of the RF tags are opposed to the maximum gain direction of the reader antenna.

Systems and methods are provided to determine a subset of D microphones in a set of N microphones on a perimeter of a space to monitor a target location. The space is divided into L interference locations. An equation is solved to determine microphone weights for the N microphones by minimizing the maximum gain for signals related to the target location and interference locations, further optimized over an l¹ penalty by applying a Lagrange multiplier to an l¹ norm of the microphone weights in a manner that determines a set of D non-zero microphones weights and a set of (N−D) microphone weights that are zero or close to zero. Microphone weights are determined for at least 2 different frequencies.

A low power IF strip architecture suitable for Zero-IF (ZIF) or low-IF (LIF) radio receivers for filtering and amplifying a received signal. The apparatus includes a plurality of sequentially connected complex filter/amplifier stages. Each stage includes a complex filter having one or more poles and an automatic gain controlled amplifier (AGC). Each AGC may be feedback or feedforward with fixed minimum and maximum gains. Each stage further includes a control circuit that produces a gain control signal for controlling the amplifier gain within the fixed minimum and maximum gains as a function of a projected amplitude level. The received signal passes through multiple stages of filtering and controlled amplification to attenuate the interfering signal and amplify the desired signal. This is done at a restricted level in each stage such that the circuits in the stages operate at efficient power saving levels. The individual gain control signals from each stage are summed in a received signal strength indicator to provide the overall gain of the apparatus. The overall gain when taken with the amplitude of the apparatus output signal determines the original strength of the desired received signal.

This invention relates to a signal processing method and apparatus for an adaptive array antenna. The objective is to suggest an adaptive procedure of computing the suboptimal weight vector for an array antenna system that provides a beampattern having its maximum gain along the direction of the mobile target signal source in a blind signal environment, where the transmitted data are not known (or not to be estimated) at the receiver. It is the ultimate goal of this invention to suggest a practical way of enhancing both the communication quality and communication capacity through the optimal weight vector of the array system that maximizes SINR(Signal to Interference+Noise Ratio). In order to achieve this goal, the method of Lagrange multiplier is modified in such a way that the suboptimal weight vector is produced with the computational load of about O(8N), which has been found to be small enough for the real-time processing of signals in most land mobile communications with the digital signal processor (DSP) off the shelf, where N denotes the number of antenna elements of the array.

The invention discloses a target clustering method of imaging satellite observation scheduling. In the method, an optimal target clustering scheme is obtained by obtaining target clustering conditions and qualities of satellite observation, a maximum gain value of the target clustering scheme of a satellite in the orbit circle and an optimal target clustering scheme and finishing a target clustering step, and a set of targets covered by various observation activities of the satellite is further obtained. The target clustering method of the imaging satellite observation scheduling can satisfy using rules and performance characteristics of various operations of the satellite with small computation cost, ensure that the satellite can finish more observation tasks within the given time and improve the using efficiency and the benefits of satellite resources, and has small imaging distortion.

A fast-settling digital automatic gain control circuit comprises first and second gain-controllable amplifiers in series. Each amplifier can be digitally switched between minimum and maximum gains by control logic that receives inputs from a multi-level voltage comparator. A peak detector connected to the output of the first gain-controlled amplifier is used to set the overall operating ranges for several threshold detectors. Four reference voltages are generated from the peak detector. The highest reference voltage is used to clock and reset the gain control logic with a hysteresis comparator to the instantaneous input signal from the first gain-controlled amplifier. The three other lower reference voltages are used to provide three-bits of digital input data to the gain control logic. Two digital controls are output, a min/max gain bit for the first gain-controlled amplifier, and a similar min/max gain bit for the second gain-controlled amplifier.

The invention discloses a detection system for radio frequency performance of a repeater product, which comprises a control computer, a testing instrument unit, a signal control unit and tested equipment. The control computer is respectively connected with the testing instrument unit, the signal control unit and the tested equipment through communication cables, and is also connected with a printer through a data wire. A method for realizing the detection system comprises the steps of starting the detection system, calibrating the system, connecting the tested equipment, automatically testingvarious radio frequency indexes, saving test data, disconnecting the tested equipment, performing system inquiry, exporting a test report form, closing the detection system and so on. The detection system can automatically, accurately and quickly test performance indexes of the repeater product such as maximum gain, output power, in-band fluctuation, noise factor, transmission time delay and so on, and form a report form with a unified form to be convenient for the maintenance and management of engineering personnel.

An image is segmented into superpixels by constructing a graph with vertices connected by edges, wherein each vertex corresponds to a pixel in the image, and each edge is associated with a weight indicating a similarity of the corresponding pixels, A subset of edges in the graph are selected to segment the graph into subgraphs, wherein the selecting maximizes an objective function based on an entropy rate and a balancing term. The edges with maximum gains are added to the graph until a number of subgraphs is equal to some threshold.

A radar antenna has a reflector and maximum gain along its boresight. The reflector has a periphery, typically circular, rectangular or elliptical. A plurality of Global Positioning System (GPS) satellite signal receiving antennas are rigidly, mechanically attached to the reflector near its periphery. The plurality of GPS satellite signal receiving antennas are connected pairwise to a phase comparator for comparing a plurality of first phase differences induced by a first GPS satellite signal received concurrently between the plurality of GPS satellite signal receiving antennas. A Phase comparator measures the phase difference of the signal received at GPS satellite signal receiving antennas pairwise thus performing a differential phase measurement. This differential phase measurement is supplied to a computer for identifying an ambiguous boresight position using the phase differences measured by the phase comparator. The position of the GPS satellites is known with respect to the geo-location of the antenna. Thus, the boresight angle is derived from the phase difference of the carrier signal from the GPS satellite being received and the mechanical alignment information between the GPS satellite receiving antennas and radar antenna boresight stored during calibration/manufacture of the radar antenna. The ambiguity in the computed boresight position is resolved by making differential phase readings using the same GPS antennas from a second GPS satellite signal supplied by a second satellite.

An array antenna pattern time domain measurement method belongs to the technical field of antennas, and comprises the following steps: measuring the patterns of array antenna units firstly, irradiating the array units from different angles (theta and Phi) by uniform plane waves, measuring the transient state responses of the array units under the irradiation of the plane waves by a digital oscilloscope, normalizing the transient state responses to obtain patterns of the array units under the conditions of uniform amplitude and cophase excitation, and synthesizing the array pattern through adopting a digital signal processing technology and a superposition principle of the patterns of the array antenna unit finally. The array antenna pattern time domain measurement method has the advantages that (1) the array pattern is beneficial for the precise synthesis under the array circumstance; (2) the patterns of the array units under the random given excitation can be measured; and (3) the array scanning grain pattern can be synthesized so as to be more beneficial for obtaining the maximum gain distribution area and the scanning blind point distribution area. The array antenna pattern time domain measurement method has the characteristics of simplicity in operation and high testing efficiency, and reduces the site requirement and the testing cost at the same time.

The invention discloses a single ended differential gain amplifier with a configurable radio frequency broadband gain. The gain amplifier comprises a single ended differential circuit with a configurable gain, a broadband amplifying circuit with the configurable gain and a buffer driving circuit with the configurable gain which are sequentially connected in series. Gain control ends of the circuits are connected with a gain control signal from an outer digital base band processing module to form a gain value of the single ended differential gain amplifier with the configurable radio frequency broadband gain in combination, according to the control of each circuit at a set fixed step pitch, fine adjustment on the gain is implemented, thus a range of the broadband signal output by the differential conforms to a range value of a set signal, and strong disturbance is effectively restrained. Since the strong detection and processing capability of a digital processing module chip of the outer base band is good for a gain control mode, the gain control is enabled not to be affected from temperature, process, noise and the like, and more precise and flexible control can be realized. The control range of the gain is a summation of the maximum gain control ranges of the three circuits with the configurable gains, so that the gain amplifier is suitable for application of the high dynamic input with strong disturbance or weak signal, and is suitable for a radio frequency chip with multiple frequencies and multiple modes of a single ended broadband radio frequency signal input.

The invention relates to a high-gain G-shaped dual-frequency monopole antenna with a loaded dual-frequency AMC reflection plate, and belongs to the technical field of electromagnetism propagation and receiving. According to the micro-strip-line-feed G-shaped dual-frequency monopole antenna with the loaded dual-frequency AMC reflection plate, the dual-frequency AMC reflection plate is loaded under the G-shaped dual-frequency antenna. The antenna is characterized in that under the condition that the section of the antenna is kept low, the maximum gain of a 2.4-GHz frequency band and a 5.2-GHz frequency band in a WLAN system reaches 7.2dBi, and backward radiation of the 2.4-GHz frequency band and the 5.2-GHz frequency band in the WLAN system reduces by 14.1dB and 13.7dB respectively. The designed high-gain dual-frequency antenna with the loaded AMC reflection plate can be used for a 2.4-GHz system (2.4GHz-2.48GHz) and a 5.2-GHz system (5.15 GHz-5.35GHz) in the WLAN system, and provides guidance for a high-gain antenna working in a dual-frequency WLAN system.

In current applications, when a short distance wireless transceiver chip transmits and receives data, transmitting power and receiving power are fixed, usually in order to achieve the purpose of signal communication, the data are transmitted and received by utilization of maximum power/maximum gain, in actual applications, under most conditions, the data are not needed to be transmitted and received by utilization of the maximum power/maximum gain, and extremely large waste of power consumption is caused. The invention provides a method dynamically controlling the transmitting power and the receiving power of the transceiver chip, communication equipment and a communication system based on an RSSI, the transmitting power and the receiving power are further lowered according to the actual applications, the power consumption is reduced, and the service life of a battery is prolonged.

The invention relates to a method and a system for adjusting an automatic exposure, which are used for a camera device. The method comprises the following steps: a, calculating a deviation measure value according to current brightness and target brightness of a picture of the camera device; b, comparing the deviation measure value with a frame reduction threshold value and a frame increasing threshold value respectively to determine a way of adjusting the frame rate of the camera device; reducing the frame rate of the camera device when the deviation measure value is smaller than the frame reduction threshold value and gain of the camera device reaches the maximum gain; increasing the frame rate of the camera device when the deviation measure value is greater than or equal to the frame reduction threshold value; keeping the frame rate of the camera device when the deviation measure value is greater than the frame reduction threshold value and is smaller than the frame increasing threshold value, wherein the frame reduction threshold value is smaller than the frame increasing threshold value.