Abstract: The present invention discloses methods of accuracy improving for code measurements in GLONASS GNSS receivers. One component of error budget in code measurements of GLONASS receivers is caused by a difference in signal delays arising in the receiver analog Front End and antenna filter on different channel frequencies specific to GLONASS satellites. Methods to compensate for differences in delays for different GLONASS channel frequencies have been proposed using data collected from a GLONASS signals simulator.

Abstract: 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

Abstract: 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

Abstract: The present invention discloses methods of accuracy improving for code measurements in GLONASS GNSS receivers. One component of error budget in code measurements of GLONASS receivers is caused by a difference in signal delays arising in the receiver analog Front End and antenna filter on different channel frequencies specific to GLONASS satellites. Methods to compensate for differences in delays for different GLONASS channel frequencies have been proposed using data collected from a GLONASS signals simulator.

Abstract: 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.

Abstract: 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.

Abstract: The present invention discloses methods of accuracy improving for code measurements in GLONASS GNSS receivers. One component of error budget in code measurements of GLONASS receivers is caused by a difference in signal delays arising in the receiver analog Front End and antenna filter on different channel frequencies specific to GLONASS satellites. Methods to compensate for differences in delays for different GLONASS channel frequencies have been proposed using data collected from a GLONASS signals simulator.

Abstract: 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.

Abstract: 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 IY and QY of the received signal in a quadrature mixer; determining a mean-square IY2 of IY; determining a mean-square QY2 of QY; determining a square/squared value of mean absolute value (modulus) |IY|2; determining a square of mean value for quadrature component ]QY[2, where values of the quadrature component QY are averaged taking into account a sign of a symbol received in a channel; determining a current absolute value (vector length) for ?{square root over (Iy2+Qy2)}; determining the current SNR based on IY2, QY2, |IY|2, ]QY[2 and ?{square root over (Iy2+Qy2)}; and compensating for a systematic error of the current SNR.

Abstract: 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 IY and QY of the received signal in a quadrature mixer; determining a mean-square IY2 of IY; determining a mean-square QY2 of QY; determining a square/squared value of mean absolute value (modulus) |IY|2; determining a square of mean value for quadrature component ]QY[2, where values of the quadrature component QY are averaged taking into account a sign of a symbol received in a channel; determining a current absolute value (vector length) for Iy2+Qy2; determining the current SNR based on IY2, QY2, |IY|2, ]QY[2 and ?{square root over (Iy2+Qy2)}; and compensating for a systematic error of the current SNR.