291 results about "Receiver front end" patented technology

A method and system for performing distributed outer loop power control in a wireless communication network are disclosed. The method includes the steps of determining a transmit power for a plurality of transmitting nodes such that signals sent from each of the transmitting nodes are received at a receiver associated with a receiving node at a predetermined signal-to-interference plus noise ratio (SINR) set point, increasing the SINR at the receiving node of one or more transmitting nodes of the plurality of transmitting nodes if a saturation value for a front end of the receiver associated with the receiving node is not near a predetermined saturation value, and decreasing the SINR at the receiving node of the one or more transmitting nodes of the plurality of transmitting nodes if the saturation value for the front end of the receiver associated with the receiving node is near the predetermined saturation value.

A BT receiver RF front end receives RF energy in a sequence of BT scan windows. Throughout a scan window, the front end is tuned to one hop frequency. Before and after the window the front end is in a disabled state. A WLAN energy detector processes an output of the front end during the window and determines whether more than a predetermined amount of RF energy was received onto the front end during the window. A BT baseband processor attempts to demodulate the output of the front end. If the WLAN energy detector determines that the predetermined amount of RF energy was received and if a BT signal could not be demodulated, then a WLAN wake-up signal is asserted, thereby causing a WLAN transceiver to be powered up to receive WLAN signals. BT scan intervals are varied in duration to facilitate a BT scan window overlapping a WLAN beacon.

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.

An integrated multimode radio includes a multimode receiver and a multimode transmitter. The multimode receiver includes a shared receiver front-end, a receiver multiplexor, and a plurality of receiver IF stages. The multimode transmitter includes a shared transmitter front-end, a transmitter multiplexor, and a plurality of transmitter IF stages.

A radio receiver supporting cancellation of thermal and phase noise in a down-converted RF signal. An inbound RF signal and blocking signal are provided directly to a passive mixer for down-conversion into a first baseband signal having data, thermal noise, and reciprocal mixing (RM) noise components. The inbound signals are also provided to a transconductance circuit, the output of which is provided to a second passive mixer for conversion into a current signal having data and blocking signal components, and a RM image. The blocking signal component and the RM image are mixed with a second LO signal, derived from the blocking signal, to produce a RM noise cancellation signal. The data component of the current signal is converted into a second baseband signal having data and thermal noise components. The first baseband signal, second baseband signal and RM noise cancellation signal are then combined through harmonic recombination.

An apparatus and method for determining the position of a user terminal comprise an antenna subsystem which is able to receive signals of GPS and TV, a receiver front end which converts the frequency of the incident signals and filters out unwanted signals so that the desired signals can be sampled, a digital processing component which accommodates the imperfections of the front end and converts the measured signals into a position information. The apparatus is capable of receiving at the user terminal, broadcast television signals from television signal transmitters; determining a first set of pseudo-ranges between the user terminal and the television signal transmitters based on a known component of the broadcast television signals; receiving at the user terminal global positioning signals from a global positioning satellites; determining a second set of pseudo-ranges between the user terminal and the global positioning satellites based on the global positioning signals; and determining a position of the user terminal based on the first and second sets of pseudo-ranges, locations of the television signal transmitters, and locations of the global positioning satellites.

A communication system is presented. The system includes one or more transmitters configured to transmit a signal, where each of the signals generated by the one or more transmitters corresponds to a respective frequency. Further, the system includes a plurality of receiver front-ends configured to receive the signal transmitted by each of the one or more transmitters. The system also includes a plurality of remodulator modules configured to translate each of the received signals to a signal having a respective intermediate frequency. In addition, the system includes a combining module configured to combine each of the signals having respective intermediate frequencies to generate a single composite signal. Also, the system includes a single analog-to-digital converter configured to process the composite signal and generate a digital output. Additionally, the system includes a digital signal processor module configured to extract the signal transmitted by each of the one or more transmitters.

There is disclosed a transceiver for use in a base station of a fixed wireless network that communicates with a plurality of subscriber transceivers via time division duplex (TDD) channels. The transceiver comprises: 1) a receiver front-end for receiving data burst transmissions from the plurality of subscriber transceivers in an uplink portion of a TDD channel, wherein the receiver front-end demodulates the received data burst transmissions into a digital baseband signal in-phase (I) signal and a digital baseband quadrature (Q) signal; 2) a first frequency domain feedforward equalization filter for receiving the I signal; 3) a second frequency domain feedforward equalization filter for receiving the Q signal; 4) an adder for producing a combined symbol estimate sequence; 5) a slicer for receiving and quantizing the combined symbol estimate sequence; and 6) a time domain feedback filter for generating a symbol correction sequence.

Pushbroom and flash lidar operations outside the visible spectrum, most preferably in near-IR but also in IR and UV, are enabled by inserting—ahead of a generally conventional lidar receiver front end—a device that receives light scattered from objects and in response forms corresponding light of a different wavelength from the scattered light. Detailed implementations using arrays of discrete COTS components—most preferably PIN diodes and VCSELs, with intervening semicustom amplifiers—are discussed, as is use of a known monolithic converter. Differential and ratioing multispectral measurements, particularly including UV data, are enabled through either spatial-sharing (e. g. plural-slit) or time-sharing.

The invention provides a framing method of the receiver front-end of multimode satellite navigation, which discloses a frontend chip of the receiving RF of multimode satellite navigation which is applicable to a plurality of satellite navigation systems. The method of the invention comprises six modules which are a multimode PF frontend low-noise amplifier/ mixer group of monolithic integrated and completed type, a reconfigurable image rejection filter, a band-variable gain amplifier, an analog-to-digital converser, a configurable frequency synthesizer and a multimode control logic module. The reconfigurable module can realize the distribution of functional parameters according to the requirement through the multimode control logic management, causing the working performance to be optimized and meeting the functional requirement on the RF front end of the receiving platform of multimode satellite navigation. The framing method of the invention requires no external supporting accessories and has the advantages of being easy to carrying out cascade connection with preceding and backward stages, high gain, small noise coefficient and good integration. The invention is applied to the current communication and navigation positioning equipment for receiving multimode satellite navigation signals, has a wide application range and quite remarkable economic benefit, is largely on demand, supports the integration making use of multimode satellite navigation positioning information, improves positioning precision and has large social benefit.

An integrated receiver with dual channel transport stream decoding and delivery substantially implemented on a single CMOS integrated circuit is described. A receiver front end provides multiple time-base clocks for two transport streams. Transport processor circuitry uses multiple PCRs to track transport streams through decoding, storage and or delivery of the decoded signals for display. Provision of a multiple time-base clock for decoding and delivering multiple transport streams allows display of the two decoded audio-video signals on independent monitors.

A radio frequency receiver front-end includes a low noise amplifier, a mixing stage, and a selectable channel filter. The low noise amplifier is operably coupled to amplify inbound RF signals to produce amplified inbound RF signals. The mixing stage is operably coupled to mix amplified inbound RF signals with a 1^st local oscillation to produce a 1^st intermediate frequency (IF) signal. The selectable channel filter is operably coupled to pass a 1^st channel of the 1^st IF signal when a channel select signal is in a 1^st state and to pass a 2^nd channel of the 1^st IF signal when the channel select signal is in a 2^nd state to produce a selected channel.

A Gaussian Frequency Shift Key (GFSK) receiver includes a receiver front end to receive a GFSK-modulated signal and convert the received GFSK-modulated signal to a baseband frequency modulated signal, a channel filter to reduce channel interference which is adjacent to a desired channel of the baseband frequency modulated signal, a demodulator to demodulate the channel filtered baseband modulated signal and to recover a sequence of symbols, a digital filter to reduce inter-symbol interference (ISI) from the sequence of symbols, a slicer to produce symbol decisions based on the filtered sequence of symbols, and a symbol-to-bit mapper to map the symbol decisions to data bits.

This invention generally relates to wired and wireless ultra wideband (UWB) data communications apparatus and methods, and in particular to UWB receiver systems and architectures, and to correlators therefore. An ultra wideband (UWB) receiver system comprising: a receiver front end to receive a UWB signal having a plurality of multipath components; and a correlator coupled to said receiver front end to correlate said UWB signal with a reference signal; and wherein said UWB signal comprises a plurality of pulses; wherein each said pulse has a plurality of multipath components; wherein said reference signal comprises a plurality of multipath components of a said pulse; and wherein said correlator comprises at least one correlator module configured to correlate a plurality of said multipath components of a said pulse with said reference signal.

The system and method for radar calibration using antenna leakage is a simplified means of calibrating the channels in amplitude and phase using natural signal leakage between antennas. It utilizes as calibration signal a wideband sinusoidal Frequency Modulated Continuous Wave (FMCW) waveform with a modulation index and modulation frequency chosen to generate spectral components (or discrete signal frequencies) that fall within the receiver Doppler passband of the radar. The calibration signal is radiated out of the transmitting antenna and enters the radar receiver front-end through the transmit-to-receive antenna leakage which occurs naturally. This technique provides a low-complexity (simpler hardware realization) means for achieving a wideband calibration rapidly and is a practical alternative to the conventional calibration approach that relies on generating offset Doppler signals that are coupled into the radar receiver front-end through the use of couplers and cabling within the radar.

This invention generally relates to wired and wireless ultra wideband (UWB) data communications apparatus and methods, and in particular to UWB receiver systems and architectures, and to UWB transmission systems and signals. A UWB receiver system for receiving a UWB signal comprising a plurality of pulses, the system comprising: a receiver front end to receive a UWB signal; a reference UWB signal store for storing a reference UWB signal; and a correlator configured to correlate said received UWB signal with a plurality of differently delayed versions of said stored reference signal to co-determine a timing and a phase of a received UWB signal pulse; whereby a UWB signal carrying data encoded by both pulse position and pulse phase is decodeable.

An integrated receiver with channel selection and image rejection substantially implemented on a single CMOS integrated circuit. A receiver front end provides programable attenuation and a programable gain low noise amplifier. LC filters integrated onto the substrate in conjunction with image reject mixers provide image frequency rejection. Filter tuning and inductor Q compensation over temperature are performed on chip. Active filters utilize multi track spiral inductors with shields to increase circuit Q. The filters incorporate a gain stage that provides improved dynamic range through the use of cross coupled auxiliary differential pair CMOS amplifiers to cancel distortion in a main linearized differential pair amplifier. Frequency planning provides additional image rejection. Local oscillator signal generation methods on chip reduce distortion. A PLL generates needed out of band LO signals. Direct synthesis generates in band LO signals. PLL VCOs are centered automatically. A differential crystal oscillator provides a frequency reference. Differential signal transmission throughout the receiver is used. ESD protection is provided by a pad ring and ESD clamping structure. Shunts utilize a gate boosting at each pin to discharge ESD build up. An IF VGA utilizes distortion cancellation achieved with cross coupled differential pair amplifiers having their V_ds dynamically modified in conjunction with current steering of the differential pairs sources.