An apparatus for surveying a position of a static point, consisting of a GNSS receiver and a mobile computing device, connected with GNSS receiver via communication interface. The mobile computing device accepts from GNSS receiver several estimations of position of a static point within a single session and computes combined result for the current session, which is the average of those estimations. After that, a reset command is send to a GNSS receiver, and another session is performed in order to get another combined result. The process continues until a required number of mutually consistent session results is collected, where ‘consistent’ means having the scatter of session results within a certain margin. Upon collecting the required number of consistent session results, they are combined to compute a single estimate of the position of a static point, which is considered as a result of survey.

A demodulator comprises a first-stage carrier demodulator and a second-stage carrier demodulator. The first-stage carrier demodulator is configured to remove or compensate for the tracking error in the baseband signal, where the tracking error comprises aggregate, channel tracking error of carrier phase for the same received band, sub-band, (baseband) GNSS satellite channel, or set GNSS channels. The second stage carrier demodulator is configured to remove or strip a carrier signal component without any unwanted image or carrier-related frequency artifacts and to prepare for correlation-based decoding or demodulation of the encoded baseband signal by the correlators. First correlators are configured to determine correlations for code phase tracking loop, where the code phase tracking loop is configured to estimate a corresponding code error component of the tracking error for the code local oscillator for a respective channel. Secondary correlators are configured to determine correlations for a carrier phase tracking loop, where the carrier phase tracking loop configured to estimate a corresponding aggregate feedback error for multiple channels or a set of channels.

An electromagnetic transmission carrying a bauded signal, such as a transmission from an orbiting satellite, is processed for Doppler shift analysis. The electromagnetic transmission is captured and a non-linear operation is performed to expose a cyclostationary feature of the captured transmission that defines a rate-line having a rate-line frequency that is related to the bauded signal and to the motion of the transmitter relative to the receiver. The rate-line frequency is tracked in time to generate data indicative of Doppler shift associated with the satellite. The data are then supplied to a tracking receiver.

Disclosed is a method for global navigation satellite system (GNSS) positioning and an electronic device performing the method. According to an example embodiment, the method includes monitoring whether an error of the GNSS positioning occurs, determining, when the error of the GNSS positioning is detected, whether a first output frequency of a first phase locked loop (PLL) used for demodulating a GNSS signal received from a satellite for the GNSS positioning is stable, and changing, when the first output frequency of the first PLL is unstable, a frequency used for demodulating the GNSS signal to a second output frequency of a second PLL or a basic frequency input to the first PLL and the second PLL.

A GNSS receiver comprises a memory interface and a vector processor. The vector processor is configured to: receive, via the memory interface, an array comprising a plurality of correlation results stored in a memory, each correlation result associated with a respective combination of possible receiver parameters for the GNSS receiver; process the array to identify a subset of the correlation results in the array; and retain, in the memory, the identified subset and discard, from the memory, those correlation results of the plurality of correlation results not in the identified subset.

A GNSS receiver comprises a memory interface and a vector processor. The vector processor is configured to: receive, via the memory interface, an array comprising a plurality of correlation results stored in a memory, each correlation result associated with a respective combination of possible receiver parameters for the GNSS receiver; process the array to identify a subset of the correlation results in the array; and retain, in the memory, the identified subset and discard, from the memory, those correlation results of the plurality of correlation results not in the identified subset.

A global navigation satellite system (GNSS) receiver for improving accuracy of a GNSS position estimation using a sigma-delta based fractional interpolation in a delay-locked loop is provided. The GNSS receiver includes a correlator, a code phase discriminator, a first loop filter, a code numerically controlled oscillator, and a sigma-delta modulator. The correlator correlates a GNSS C/A signal received from a satellite with a locally generated GNSS C/A code by multiplying the locally generated GNSS C/A code with incoming data samples. The code phase discriminator determines a delay between the locally generated GNSS C/A code and the GNSS C/A signal received from the satellite. The first loop filter averages the delay measured by the code phase discriminator. The code numerically controlled oscillator generates the local GNSS C/A code based on a unique CA code that corresponds to the satellite. The sigma-delta modulator imparts a fractional delay to the locally generated GNSS C/A code based on an output of the first loop filter.

A global navigation satellite system (GNSS) receiver for improving accuracy of a GNSS position estimation using a sigma-delta based fractional interpolation in a delay-locked loop is provided. The GNSS receiver includes a correlator, a code phase discriminator, a first loop filter, a code numerically controlled oscillator, and a sigma-delta modulator. The correlator correlates a GNSS C/A signal received from a satellite with a locally generated GNSS C/A code by multiplying the locally generated GNSS C/A code with incoming data samples. The code phase discriminator determines a delay between the locally generated GNSS C/A code and the GNSS C/A signal received from the satellite. The first loop filter averages the delay measured by the code phase discriminator. The code numerically controlled oscillator generates the local GNSS C/A code based on a unique CA code that corresponds to the satellite. The sigma-delta modulator imparts a fractional delay to the locally generated GNSS C/A code based on an output of the first loop filter.

A Global Navigation Satellite System (GNSS) receiver for performing GNSS outlier detection and rejection is provided. When the GNSS receiver receives GNSS signals from satellites in the GNSS, the GNSS receiver processes the GNSS signals to perform positioning. Then, the GNSS receiver sequentially performs a Doppler-pseudorange comparison, a Random Sampling Consensus (RANSAC) check for selected subsets of the satellites, and a history-based check for the satellites to determine a status of each satellites as an outlier or an inlier. Specifically, in the RANSAC check, the subsets of the satellites are selected using results of the Doppler-pseudorange comparison as inputs to filter the satellites, thus reducing the number of subsets needed for computation in the RANSAC check. The status of the satellites are recorded for the history-based check, which further exploits the correlations of outliers across time.

A Global Navigation Satellite System (GNSS) receiver for performing GNSS outlier detection and rejection is provided. When the GNSS receiver receives GNSS signals from satellites in the GNSS, the GNSS receiver processes the GNSS signals to perform positioning. Then, the GNSS receiver sequentially performs a Doppler-pseudorange comparison, a Random Sampling Consensus (RANSAC) check for selected subsets of the satellites, and a history-based check for the satellites to determine a status of each satellites as an outlier or an inlier. Specifically, in the RANSAC check, the subsets of the satellites are selected using results of the Doppler-pseudorange comparison as inputs to filter the satellites, thus reducing the number of subsets needed for computation in the RANSAC check. The status of the satellites are recorded for the history-based check, which further exploits the correlations of outliers across time.