A signal receiving equipment includes a reception unit configured to receive signals from a GNSS satellite, a first selection unit configured to select a plurality of signals from among the signals received by the reception unit using a preset first parameter, a first positioning unit configured to perform at least positioning of a location by code-based positioning using the plurality of signals selected by the first selection unit, a second selection unit configured to select a plurality of signals from among the signals received by the reception unit using a preset second parameter, and a second positioning unit configured to perform positioning of a location and time synchronization by carrier-phase-based positioning using the plurality of signals selected by the second selection unit, with coordinates indicated by the location positioned by the first positioning unit as initial coordinates.

A method is provided for acquiring a signal from a satellite in a global navigation satellite system. The signal includes a pseudorandom code. The method includes, for each time period of a plurality of time periods: generating samples of the signal, segments of the samples of the signal are correlated with a local copy of the pseudorandom code, thereby producing correlation values for the time period. A discrete Fourier transform is performed using, as inputs, the correlation values for the respective time period, thereby producing a frequency representation of the correlation values for the time period. The frequency representations of the correlation values for the plurality of time periods are combined according to a data hypothesis. When a magnitude of the combined frequency representations meets predefined criteria, a frequency corresponding to the magnitude is selected as a tracking frequency for the satellite.

A method is provided for acquiring a signal from a satellite in a global navigation satellite system. The signal includes a pseudorandom code. The method includes, for each time period of a plurality of time periods: generating samples of the signal, segments of the samples of the signal are correlated with a local copy of the pseudorandom code, thereby producing correlation values for the time period. A discrete Fourier transform is performed using, as inputs, the correlation values for the respective time period, thereby producing a frequency representation of the correlation values for the time period. The frequency representations of the correlation values for the plurality of time periods are combined according to a data hypothesis. When a magnitude of the combined frequency representations meets predefined criteria, a frequency corresponding to the magnitude is selected as a tracking frequency for the satellite.

A method for detecting a probe signal at an estimated code delay and an estimated doppler frequency includes: (i) dividing a period of the probe signal into sections each of a predetermined duration; (ii) assigning to each section one of a multiple code categories, each code category being indicative of a signal pattern of the probe signal within the section; and (iii) selecting multiple phase categories for a sinusoidal signal, each phase category being indicative of a range of phases in the sinusoidal signal. Thereafter, the method includes (i) receiving a signal from which the probe signal is to be detected; (ii) dividing the received signal into sections each of the predetermined duration; (iii) assigning each section of the received signal both a corresponding code category and a corresponding phase category, based respectively on the estimated code delay and the doppler frequency; and (iv) separately accumulating sections of the received signal according to the assigned code and phase categories of each section.

A method for detecting a probe signal at an estimated code delay and an estimated doppler frequency includes: (i) dividing a period of the probe signal into sections each of a predetermined duration; (ii) assigning to each section one of a multiple code categories, each code category being indicative of a signal pattern of the probe signal within the section; and (iii) selecting multiple phase categories for a sinusoidal signal, each phase category being indicative of a range of phases in the sinusoidal signal. Thereafter, the method includes (i) receiving a signal from which the probe signal is to be detected; (ii) dividing the received signal into sections each of the predetermined duration; (iii) assigning each section of the received signal both a corresponding code category and a corresponding phase category, based respectively on the estimated code delay and the doppler frequency; and (iv) separately accumulating sections of the received signal according to the assigned code and phase categories of each section.

A GNSS signal acquisition method based on FPGA step-by-step code phase refinement comprises steps as follows: (1) Coarse acquisition: correlate all received data with the locally generated carrier and the complete pseudo-random code to find the maximum correlation value; obtain the carrier and the rough code phase for fine acquisition if the maximum correlation value conforms to the acquisition threshold; otherwise, repeat Step (1). (2) Fine acquisition: feedback the carrier and the coarse acquisition code phase value from Step (1) to the controller so that the controller can intercept partial of the received signal for mixing with the local carrier from Step (1); then, correlate the result with partial pseudo-random code after eliminating the influence of the carrier to obtain a code phase with higher accuracy.

A GNSS signal acquisition method based on FPGA step-by-step code phase refinement comprises steps as follows: (1) Coarse acquisition: correlate all received data with the locally generated carrier and the complete pseudo-random code to find the maximum correlation value; obtain the carrier and the rough code phase for fine acquisition if the maximum correlation value conforms to the acquisition threshold; otherwise, repeat Step (1). (2) Fine acquisition: feedback the carrier and the coarse acquisition code phase value from Step (1) to the controller so that the controller can intercept partial of the received signal for mixing with the local carrier from Step (1); then, correlate the result with partial pseudo-random code after eliminating the influence of the carrier to obtain a code phase with higher accuracy.

A positioning system includes equipment that receives a signal from a GNSS satellite, and a server apparatus that is connected to the equipment via a communication network. The equipment includes a memory and a processor configured to transmit information indicated by the signal to the server apparatus, and perform positioning of the equipment by using the information indicated by the signal. The server apparatus includes a memory and a processor configured to perform positioning of the equipment by using the information indicated by the signal received from the equipment.

A positioning system includes equipment that receives a signal from a GNSS satellite, and a server apparatus that is connected to the equipment via a communication network. The equipment includes a memory and a processor configured to transmit information indicated by the signal to the server apparatus, and perform positioning of the equipment by using the information indicated by the signal. The server apparatus includes a memory and a processor configured to perform positioning of the equipment by using the information indicated by the signal received from the equipment.

A method of receiving two chip-by-chip multiplexed CSK signals (e.g., GNSS signals) and searching for a non-CSK signal with optimal performance at a given digit capacity of a sampling memory resided in parallel correlators. For CSK signals Prompt, Early and Late results for each of possible code shift are calculated as different sums of four punctured convolutions. Depending on configuration, the method allows to receive both multiplexed CSK signals with lesser quality or one of the CSK signals with better quality. The method can be implemented as an apparatus with four punctured correlators, a set of multipliers by 1 or 2.sup.N, another set of multipliers by 1 or 0, summers of four input to one result, a RAM, searchers of maximum, and conditional commutators.