Topcon Positioning Systems, Inc.

Fedor Borisovich Serkin

Andrey Vladimirovich Veitsel

Nikolay Afanasievich Vazhenin

Vladimir Victorovich Veitsel

Dmitry Anatolyevich Rubtsov

Nikolay Afanasyevich Vazhenin

Leonid Victorovich Purto

Sergey Sayarovich Bogoutdinov

Vladimir Viktorovich Veitsel

Igor Anatolievich Orlovsky

Dmitry Yuryevich Goldberg

An apparatus includes an antenna, RF path, Analog to Digital convertor (ADC), filter, and navigation channel for processing a received GNSS signal based on a navigation clock. A communication modem is configured to receive the signal via a first antenna, RF path, and ADC and process the received signal in order to generate a signal based on a modem clock. The communication modem is further configured to transmit the signal based on the modem clock using a R+1 antenna via a R+1 RF path and a Digital to Analog Convertor (DAC). A multichannel synchronous signal analysis system (MSSAS) receives outputs of the ADCs and processes them using a plurality of decimators and plurality data receivers. Each of the decimators is configured to process the outputs of the ADCs and output data to one of a plurality of data receivers. A CPU is configured to control all of the devices.

Multichannel synchronous analysis system for analyzing global navigation satellite system signals and methods of signal processing

Method of reducing multipath effects on phase measurements, including receiving radio signals with different pseudo-random codes transmitted by at least four base stations, each at particular frequency received by one channel; measuring delay difference and phase difference from different pairs of base stations; calculating a current position of the receiver based on the measured phase differences and delay differences, wherein the base stations differ in pseudo-random codes at same frequencies or differ in carrier frequency or polarization type if using the same pseudo-random codes, and wherein a number of channels in the receiver exceeds a number of channels needed for the calculating of the current position; detecting anomalous jumps in phase of one or more channels, based on first or second derivative of the phase, as being indicative of multipath signal reception; removing those channels from calculation of current position; and calculating current position based on remaining channels.

Method and device for reducing multipath channel effects on phase measurements in navigation radio systems

Navigation receiver includes antennas receiving signals from different satellite constellations, Low Noise Amplifiers, a Block of Analog Filters, a Block of Quadrature mixers (BQM) translating in phase and quadrature signals to an intermediate frequency, analog converters digitizing the in phase and quadrature signals, a Block of Digital Quadrature Mixers (BDQM) shifting the digitized signals to zero frequency, a Set Block of Digital Filters (SBDF) band-pass filtering the shifted signals, and reducing a sampling rate, and a Block of Digital Processing (BDP) calculating coordinates, all series-connected; a Block of Digital Generators (BDG) for fine control of the BDQM; and a Block of Analog Generators (BAG) that defines which signal is processed by its corresponding BQM; SBDF including Blocks of Digital Filters (BDFs), each BDF including a chain of Blocks of MultiRate Filters for antialiasing filtering/down-sampling of shifted signals, programmable commutators for controlling decimation, and FIR-filters; each BDF controlled by control block.

Block of digital filters for multisystem navigational receivers integrated with data transmission systems

Position determination for a mobile station is achieved through the modification of certain Wi-Fi access point and station signals, that are radiated by a certain master (i.e., guiding) base station, combined with slave (i.e., guided) stations having known coordinates, and processing the signals received from these base stations at the mobile station to determine the desired position.

Position determination of a mobile station using modified Wi-Fi signals

An apparatus to measure signal-to-thermal noise ratio (SNR) and signal-to-pulse noise ratio (SPNR), the apparatus including a quadrature mixer, a pulse noise reduction unit, an SNR estimation unit and an offset compensation unit, connected in series, the quadrature mixer receiving the input radio signal and outputting an in-phase component and a quadrature component; a pulse noise separation unit, and an SPNR estimation unit connected series, the pulse noise reduction unit and the pulse noise separation unit inputting the in-phase and quadrature components; the SPNR estimation unit inputting a filtered in-phase component from the pulse noise reduction unit. The offset compensation unit outputs a current SNR. The SPNR estimation unit outputs a current SPNR. The pulse noise separation unit includes a first LPF, an impulse noise separator and an HPF, connected in series; and a second LPF, a pulse noise detection unit and an inverter, connected in series.

Method and apparatus for estimating the current signal-to-thermal noise ratio and signal-to-pulse noise ratio

Apparatus to measure signal-to-thermal noise ratio (SNR) and signal-to-pulse noise ratio (SPNR) includes a pulse noise reduction unit, an SNR estimation unit and an offset compensation unit; a pulse noise separation unit, and an SPNR estimation unit. Pulse noise separation unit includes (i) a first low pass filter (LPF), an impulse noise separator and a high pass filter (HPF), connected in series; and (ii) a second LPF, a pulse noise detection unit and an inverter. Pulse noise detection unit includes two channels, each with a high pass filter, an absolute value calculation unit, a low pass filter, a comparator, a pulse generator. The channels connect to OR gate, which outputs a pulse detection signal. Pulse noise reduction unit and pulse noise separation unit input in-phase and quadrature components. The SPNR estimation unit inputs a filtered in-phase component. The offset compensation unit outputs SNR, and the SPNR estimation unit outputs SPNR.

Apparatus for estimating a current SNR of a signal, including an SNR estimator and an offset compensator connected in series, the offset compensator outputting the current SNR; the SNR estimator including (i) a first squaring unit, a summer, a square root unit, a first mean unit, a first subtractor, a scaling unit, a divider, a second subtractor and a decibel (dB)-recalculator, all connected in series, wherein an output of the second squaring unit is also connected to the divider; (ii) a third squaring unit connected to the first summer, and a second mean unit connected to an output of the summer at its input and to the subtractor at its output; and (iii) a correction calculator connected to the square root unit and to the second subtractor; the first squaring unit inputting an I component of the signal; and the second squaring unit inputting a Q component of the signal.

Method and apparatus for estimating the current signal-to-noise ratio

A method of estimating current SNR in a sequence of symbols, including receiving a signal representing an additive mixture y(t)=s(t)+n(t) of a sequence of phase-modulated symbols with fixed length and phase modulation s(t) and including white Gaussian noise (AWGN) n(t); separating quadrature components Iand Qof the received signal in a quadrature mixer; determining a mean-squareof I; determining a mean-squareof Q; determining a square/squared value of mean absolute value (modulus); determining a square of mean value for quadrature component, where values of the quadrature component Qare averaged taking into account a sign of a symbol received in a channel; determining a current absolute value (vector length) for; determining the current SNR based on,, ||,and &#x221a;{square root over (I+Q)}; and compensating for a systematic error of the current SNR.

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Moscow, Russia

Fedor Borisovich Serkin