A tones processing system including an interference tone determination module (ITDM), an interference tone tracker module (ITTM) and an interference tone removal module (ITRM) is provided. The ITDM sequentially searches for one or more continuous wave interference (CWI) tones in N samples of intermediate frequency (IF) data within a programmable signal frequency band. The ITTM tracks the detected CWI tones. The ITRM removes the tracked CWI tones from the N samples of IF data using one or more interference tone removal units (ITRUs). Each of the ITRUs includes a second signal generator, a second mixer, a tone filter for suppressing the tracked CWI tones, and a quantizer for reducing the number of processing bits in a tone suppressed output signal. The ITRM performs frequency shift compensation and phase rotation compensation with reduced logic area and power consumption in the global navigation satellite system, receiver.
G01S 19/35 - Détails de construction ou détails de matériel ou de logiciel de la chaîne de traitement des signaux
G01S 19/36 - Détails de construction ou détails de matériel ou de logiciel de la chaîne de traitement des signaux concernant l'étage d'entrée du récepteur
G01S 19/37 - Détails de matériel ou de logiciel de la chaîne de traitement des signaux
2.
Tones processing system in a global navigation satellite system receiver
A tones processing system including an interference tone determination module (ITDM), an interference tone tracker module (ITTM) and an interference tone removal module (ITRM) is provided. The ITDM sequentially searches for one or more continuous wave interference (CWI) tones in N samples of intermediate frequency (IF) data within a programmable signal frequency band. The ITTM tracks the detected CWI tones. The ITRM removes the tracked CWI tones from the N samples of IF data using one or more interference tone removal units (ITRUs). Each of the ITRUs includes a second signal generator, a second mixer, a tone filter for suppressing the tracked CWI tones, and a quantizer for reducing the number of processing bits in a tone suppressed output signal. The ITRM performs frequency shift compensation and phase rotation compensation with reduced logic area and power consumption in the global navigation satellite system, receiver.
G01S 19/35 - Détails de construction ou détails de matériel ou de logiciel de la chaîne de traitement des signaux
G01S 19/36 - Détails de construction ou détails de matériel ou de logiciel de la chaîne de traitement des signaux concernant l'étage d'entrée du récepteur
G01S 19/37 - Détails de matériel ou de logiciel de la chaîne de traitement des signaux
3.
Time interval measurement code-division multiple access transceiver
A time interval measurement code-division multiple access (CDMA) transceiver including a clock manager, a transmit channel, one or more receive channels, and a processor for performing time interval measurement in two-way satellite time and frequency transfer and satellite ranging, is provided. The transmit channel generates a spread signal that is digitally phase modulated to generate and transmit the modulated intermediate frequency signal. The baseband processing of the received signal from each of the remote ground stations is performed in receive channels. A transmission time generation module generates a transmission time measurement and a reception time generation module generates a reception time measurement. The transmission time measurement and the reception time measurement are generated on a latch measurement signal that is received from a latch epoch generation module in each of the receive channels.
H04B 7/26 - Systèmes de transmission radio, c.-à-d. utilisant un champ de rayonnement pour communication entre plusieurs postes dont au moins un est mobile
H04W 72/08 - Affectation de ressources sans fil sur la base de critères de qualité
A tones processing system including an interference tone determination module (ITDM), an interference tone tracker module (ITTM) and an interference tone removal module (ITRM) is provided. The ITDM sequentially searches for one or more continuous wave interference (CWI) tones in N samples of intermediate frequency (IF) data within a programmable signal frequency band. The ITTM tracks the detected CWI tones. The ITRM removes the tracked CWI tones from the N samples of IF data using one or more interference tone removal units (ITRUs). Each of the ITRUs includes a second signal generator, a second mixer, a tone filter for suppressing the tracked CWI tones, and a quantizer for reducing the number of processing bits in a tone suppressed output signal. The ITRM performs frequency shift compensation and phase rotation compensation with reduced logic area and power consumption in the global navigation satellite system receiver.
G01S 19/35 - Détails de construction ou détails de matériel ou de logiciel de la chaîne de traitement des signaux
G01S 19/36 - Détails de construction ou détails de matériel ou de logiciel de la chaîne de traitement des signaux concernant l'étage d'entrée du récepteur
G01S 19/37 - Détails de matériel ou de logiciel de la chaîne de traitement des signaux
5.
TONES PROCESSING SYSTEM IN A GLOBAL NAVIGATION SATELLITE SYSTEM RECEIVER
A tones processing system including an interference tone determination module (ITDM), an interference tone tracker module (ITTM)and an interference tone removal module (ITRM) is provided. The ITDM sequentially searches for one or more continuous wave interference (CWI) tones in N samples of intermediate frequency (IF) data within a programmable signal frequency band. The ITTM tracks the detected CWI tones. The ITRM removes the tracked CWI tones from the N samples of IF data using one or more interference tone removal units (ITRUs). Each of the ITRUs includes a second signal generator, a second mixer, a tone filter for suppressing the tracked CWI tones, and a quantizer for reducing the number of processing bits in a tone suppressed output signal. The ITRM performs frequency shift compensation and phase rotation compensation with reduced logic area and power consumption in the global navigation satellite system receiver.
A global navigation satellite system (GNSS) receiver including a sequential chip mixed frequency correlator array system (SCMFCAS) is provided. The SCMFCAS includes P signal generators, each receiving N samples of intermediate frequency (IF) data of a GNSS signal. Each signal generator includes a primary mixer, a pseudo random noise code generator, and Q mixed frequency correlators (MFCs). Each MFC generates accumulated correlation components of the N samples of the IF data by processing the N samples of the IF data. Adders and subtractors operably connected to the SCMFCAS are time division multiplexed for generating correlation values of a positive frequency and a negative frequency of the N samples of the IF data by combining the accumulated correlation components. Time division multiplexing the adders and the subtractors across the SCMFCAS and generation of the correlation values reduce logic area of the SCMFCAS, thereby reducing power consumption of the GNSS receiver.
A global navigation satellite system (GNSS) signal tracking system (GNSSSTS), deployed in a tracking channel of a GNSS baseband engine, includes a piecewise down sampling module for generating code bit accumulated values (CBAVs) at different time instants at a reduced rate from samples of intermediate frequency data received at a high rate, and a pseudo random noise (PRN) code generation module for generating a PRN code bit sequence (PRNCBS) corresponding to a GNSS signal and storing arms of the PRNCBS. The GNSSSTS includes a primary mixer for generating a despread value for a selected arm of the PRNCBS and a phase component generation module (PCGM) for generating inphase and quadrature phase correlation components of the despread value for storage in a storage array. The primary mixer, the PCGM, and the storage array perform their functions continuously for each CBAV generated at a corresponding time instant in a time multiplexed manner.
A global navigation satellite system (GNSS) receiver including a sequential chip mixed frequency correlator array system (SCMFCAS) is provided. The SCMFCAS includes P signal generators, each receiving N samples of intermediate frequency (IF) data of a GNSS signal. Each signal generator includes a primary mixer, a pseudo random noise code generator, and Q mixed frequency correlators (MFCs). Each MFC generates accumulated correlation components of the N samples of the IF data by processing the N samples of the IF data. Adders and subtractors operably connected to the SCMFCAS are time division multiplexed for generating correlation values of a positive frequency and a negative frequency of the N samples of the IF data by combining the accumulated correlation components. Time division multiplexing the adders and the subtractors across the SCMFCAS and generation of the correlation values reduce logic area of the SCMFCAS, thereby reducing power consumption of the GNSS receiver.
A global navigation satellite system (GNSS) antenna sharing receiver (GNSSASR) for sharing a GNSS antenna with one or more secondary GNSS receivers is provided. The GNSSASR includes an input radio frequency (RF) port for receiving a GNSS signal from the GNSS antenna, one or more output RF ports for transmitting the GNSS signal to the secondary GNSS receivers, a coupler for reducing attenuation in the GNSS signal transmitted to the secondary GNSS receivers, a power supply circuit for supplying a direct current (DC) voltage with reduced loss to the GNSS antenna based on availability of a secondary GNSS receiver, and a current monitoring circuit for monitoring DC flow to the GNSS antenna from the power supply circuit, limiting an increase in the DC flow due to a fault in the GNSS antenna, and indicating a fault in the GNSS antenna to the GNSSASR and the secondary GNSS receivers.
G01S 19/36 - Détails de construction ou détails de matériel ou de logiciel de la chaîne de traitement des signaux concernant l'étage d'entrée du récepteur
G01S 19/37 - Détails de matériel ou de logiciel de la chaîne de traitement des signaux
G01S 19/14 - Récepteurs spécialement adaptés pour des applications spécifiques
G01S 19/33 - Fonctionnement multimode dans différents systèmes transmettant des messages horodatés, p. ex. GPS/GLONASS
10.
Cross correlation detection in a satellite navigation receiver
A method and a system for detecting cross correlation in a satellite navigation receiver (SNR) in real tune are provided. The SNR parallelly receives navigation signals from multiple satellites via multiple input channels. The SNR extracts ephemeris data from sub-frames of navigation data of each of the navigation signals. The SNR compares the ephemeris data of each navigation signal with the ephemeris data of another navigation signal. The SNR detects cross correlation between the navigation signals when the ephemeris data comparison results in a match and discards the navigation signal with low signal strength. The SNR also retrieves a ranging code from the sub-frames of navigation data of each navigation signal. The SNR compares the ranging code with a pre-programmed satellite identity code of a corresponding satellite. The SNR detects cross correlation when the code comparison results in a mismatch and discards the navigation signal with the mismatched ranging code.
G01S 19/27 - Acquisition ou poursuite des signaux émis par le système création, prévision ou correction des éphémérides ou des almanachs au sein du récepteur
G01S 19/08 - Éléments coopérantsInteraction ou communication entre les différents éléments coopérants ou entre les éléments coopérants et les récepteurs fournissant des informations d'intégrité, p. ex. la santé des satellites ou la qualité des éphémérides
G01S 19/07 - Éléments coopérantsInteraction ou communication entre les différents éléments coopérants ou entre les éléments coopérants et les récepteurs fournissant des données pour corriger les données de positionnement mesurées, p. ex. DGPS [GPS différentiel] ou corrections ionosphériques
G01S 19/20 - Contrôle d'intégrité, détection ou isolation des défaillances du segment spatial
A method and a system for defecting cross correlation in a satellite navigation receiver (SNR) in real time are provided. The SNR parallelly receives navigation signals from multiple satellites via multiple input channels. The SNR extracts ephemeris data from sub-frames of navigation data of each of the navigation signals. The SNR compares the ephemeris data of each navigation signal with the ephemeris data of another navigation signal. The SNR detects cross correlation between the navigation signals when the ephemeris data comparison results in a match and discards the navigation signal with low signal strength. The SNR also retrieves a ranging code from the sub-frames of navigation data of each navigation signal. The SNR compares the ranging code with a pre-programmed satellite identity code of a corresponding satellite. The SNR detects cross correlation when the code comparison results in a mismatch and discards the navigation signal with the mismatched ranging code.
G01S 19/27 - Acquisition ou poursuite des signaux émis par le système création, prévision ou correction des éphémérides ou des almanachs au sein du récepteur
G01S 19/08 - Éléments coopérantsInteraction ou communication entre les différents éléments coopérants ou entre les éléments coopérants et les récepteurs fournissant des informations d'intégrité, p. ex. la santé des satellites ou la qualité des éphémérides
G01S 19/07 - Éléments coopérantsInteraction ou communication entre les différents éléments coopérants ou entre les éléments coopérants et les récepteurs fournissant des données pour corriger les données de positionnement mesurées, p. ex. DGPS [GPS différentiel] ou corrections ionosphériques
G01S 19/20 - Contrôle d'intégrité, détection ou isolation des défaillances du segment spatial
A method and a system for reducing time to first fix (TTFF) in a satellite navigation receiver generate a navigation data structure including three sub-frames. A first sub-frame and a second sub-frame accommodate selective ephemeris data. The third sub-frame accommodates a text message including almanac data optionally, ionospheric data, coordinated universal time (UTC) data, textual data optionally, and any combination thereof. A signal generation system (SGS) in the system selectively groups the almanac data, the ionospheric data, and the UTC data, and selectively transmits the navigation data with the almanac data or free of the almanac data in the navigation data structure to the satellite navigation receiver. The signal generation system also staggers the navigation data in each sub-frame into a first portion and a second portion for parallelly transmitting the navigation data over a first carrier frequency and a second carrier frequency in reduced time.
G01S 19/05 - Éléments coopérantsInteraction ou communication entre les différents éléments coopérants ou entre les éléments coopérants et les récepteurs fournissant des données d'assistance
13.
Time to first fix optimization in a satellite navigation receiver
A method and a system for reducing time to first fix (TTFF) in a satellite navigation receiver (SNR) includes constructing an integrated satellite constellation system (ISCS) for transmitting navigation signals over a combination of a first carrier frequency, a second carrier frequency, and a third carrier frequency. The ISCS includes a predetermined number of geosynchronous satellites positioned at first predetermined geographic coordinates in a geosynchronous orbit and a predetermined number of geostationary satellites positioned at second predetermined geographic coordinates in a geostationary orbit. The ISCS transmits navigation data to the SNR over the combination of the first carrier frequency, the second carrier frequency, and the third carrier frequency in reduced time, thereby reducing the TTFF in the SNR. The method and the system also reduce TTFF in a hot start mode and a snap start mode of the SNR by utilizing the third carrier frequency as a data channel.
G01S 19/07 - Éléments coopérantsInteraction ou communication entre les différents éléments coopérants ou entre les éléments coopérants et les récepteurs fournissant des données pour corriger les données de positionnement mesurées, p. ex. DGPS [GPS différentiel] ou corrections ionosphériques
G01S 19/05 - Éléments coopérantsInteraction ou communication entre les différents éléments coopérants ou entre les éléments coopérants et les récepteurs fournissant des données d'assistance
14.
Cross correlation detection in a satellite navigation receiver
A method and a system for detecting cross correlation in a satellite navigation receiver (SNR) in real time are provided. The SNR parallelly receives navigation signals from multiple satellites via multiple input channels. The SNR extracts ephemeris data from sub-frames of navigation data of each of the navigation signals. The SNR compares the ephemeris data of each navigation signal with the ephemeris data of another navigation signal. The SNR detects cross correlation between the navigation signals when the ephemeris data comparison results in a match and discards the navigation signal with low signal strength. The SNR also retrieves a ranging code from the sub-frames of navigation data of each navigation signal. The SNR compares the ranging code with a pre-programmed satellite identity code of a corresponding satellite. The SNR detects cross correlation when the code comparison results in a mismatch and discards the navigation signal with the mismatched ranging code.
A method and a system for reducing time to first fix (TTFF) in a satellite navigation receiver generate a navigation data structure including three sub-frames. A first sub-frame and a second sub-frame accommodate selective ephemeris data. The third sub-frame accommodates a text message including almanac data optionally, ionospheric data, coordinated universal time (UTC) data, textual data optionally, and any combination thereof. A signal generation system (SGS) in the system selectively groups the almanac data, the ionospheric data, and the UTC data, and selectively transmits the navigation data with the almanac data or free of the almanac data in the navigation data structure to the satellite navigation receiver. The signal generation system also staggers the navigation data in each sub-frame into a first portion and a second portion for parallelly transmitting the navigation data over a first carrier frequency and a second carrier frequency in reduced time.
G01S 19/24 - Acquisition ou poursuite des signaux émis par le système
G01S 19/05 - Éléments coopérantsInteraction ou communication entre les différents éléments coopérants ou entre les éléments coopérants et les récepteurs fournissant des données d'assistance
16.
Satellite navigation system for optimal time to first fix using code and carrier diversity
A satellite navigation receiver and method for enhancing time to first fix are provided. The receiver comprises a radio frequency (RF) translator, correlator blocks, and a navigation data processor. The RF translator conditions navigation signals over carrier frequencies. The correlator blocks comprise a predetermined number of correlator channels configured for the carrier frequencies. The predetermined number of correlator channels is divided for parallel collection of sub-frames of navigation data across one or more operation service codes. The sub-frames of navigation data are collected across one or more operation service codes and on one of the carrier frequencies. The sub-frames of navigation data are collected across the carrier frequencies and on one of the operation service codes. The sub-frames of navigation data are collected across the carrier frequencies and across the operation service codes. The navigation data processor processes the parallelly collected sub-frames to estimate position of the satellite navigation receiver.
A method and system for transmitting navigation data to a satellite navigation receiver for reducing time to first fix is provided. A signal generation system generates a navigation data structure comprising a first sub-frame and a second sub-frame for accommodating selective ephemeris data, a third sub-frame for accommodating first parameters of almanac data, and a fourth sub-frame for accommodating a text message comprising second parameters of almanac data, and transmits the selective ephemeris data and the first and second parameters of almanac data to the satellite navigation receiver. The configuration of the navigation data structure enables the satellite navigation receiver to collect the navigation data in reduced time. Each satellite of a constellation simultaneously transmits distinct first parameters of the almanac data in the third sub-frame of the navigation data structure to the satellite navigation receiver, thereby allowing the satellite navigation receiver to receive collective almanac data in reduced time.
G01S 19/02 - Détails des installations de contrôle terrestres ou spatiales
G01S 19/01 - Systèmes de positionnement par satellite à radiophares émettant des messages horodatés, p. ex. GPS [Système de positionnement global], GLONASS [Système global de navigation par satellite] ou GALILEO
G01S 19/23 - Test, contrôle, correction ou étalonnage d'un élément récepteur
C between each N code bit sequences. A first carrier and code generator is provided within each signal generator for generating an in-phase and a quadrature-phase component of a first carrier signal, and N code bit sequences. The first carrier and code generators within adjacently arranged signal generators are programmed with same code chip offset, different carrier signal frequency, different code frequency, and different code phase offset. M in-phase and M quadrature-phase carrier mixed signals, and N code bit sequences are generated by the M signal generators based on the programmable parameter.
A system and method of achieving a reduced time for first fix in a global positioning system receiver (GPS). The GPS receiver includes a low gate count sequential multitap correlator (102) in combination with a digital signal processor (106) and a down converter (101). The low gate count sequential multitap correlator (102) conducts sequential correlation on the incoming GPS signals using a multitapping and pipelining scheme. The multitapping process involves tapping the shift register and simultaneously correlating the signal samples and tapped chips. The pipelining process includes sampling data, mapping incoming samples, shifting carrier acquisition code, multiplying and accumulating the code and signal products. The digital signal processor conducts the frequency search.
H04L 27/06 - Circuits de démodulationCircuits récepteurs
H04B 1/00 - Détails des systèmes de transmission, non couverts par l'un des groupes Détails des systèmes de transmission non caractérisés par le milieu utilisé pour la transmission
This invention is directed to a method for estimating and compensating for multipath errors in a pseudorandom noise ranging receiver. The method exploits the asymmetry of the correlation function and proportionately relates it to the magnitude of multipath error. In a pseudorandom noise ranging receiver, the correlation function is obtained by generating the local pseudorandom noise sequences at different programmed non-uniform phases resulting in non-uniformly spaced correlators. Numerically controlled oscillators, code generators and shift registers are programmed to determine the correlation values at non-uniformly distributed points on a correlation function. Curve fitting is undertaken to determine the code phase at which the correlation function peaks. A proportionality constant is applied to the measure of asymmetry of the correlation function to determine the multipath error in the pseudorandom noise signal. A filter is used to detect and eliminate outliers.
H03K 9/00 - Démodulation d'impulsions qui ont été modulées par un signal à variation continue
H04B 1/00 - Détails des systèmes de transmission, non couverts par l'un des groupes Détails des systèmes de transmission non caractérisés par le milieu utilisé pour la transmission
A method for acquisition of a weak signal from a satellite in the presence of a strong interfering signal from another satellite is disclosed. The method encompasses identifying the auto-correlation peak due to the weak satellite signal from the cross correlation peaks due to the strong satellite signal. This invention presents a method and apparatus of acquiring a weak satellite signal in the presence of a strong interfering satellite signal in a receiver by two techniques, namely, the millisecond boundary correlation histogram method, and the frequency response correlation histogram method. Both the techniques distinguish between the correlation characteristics for auto-correlation and cross-correlation. The apparatus presented in the invention implements the methods of weak satellite signal acquisition in presence of a strong interfering satellite signal in a pseudorandom noise (PRN) receiver.
G01S 1/00 - Radiophares ou systèmes de balisage émettant des signaux ayant une ou des caractéristiques pouvant être détectées par des récepteurs non directionnels et définissant des directions, situations ou lignes de position déterminées par rapport aux émetteurs de radiophareRécepteurs travaillant avec ces systèmes
brevets
