Abstract: 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.

Abstract: A GNSS correlator comprises a buffer and a processing unit. The buffer is configured to store input data representing sample values of a GNSS signal captured over a pre-defined time window. The processing unit is configured to receive one or more correlation parameters in a control signal, and, in a first pass, read the input data from the buffer and perform a first correlation operation on the input data, and, in a second pass, re-read the same input data from the buffer and perform a second correlation operation on the same input data, wherein the second correlation operation is different to the first correlation operation.

Abstract: A ranging code correlation function detection system for use in a global navigation satellite system (GNSS) receiver includes a correlation block to correlate a digitized GNSS signal (e.g. at or above a critical sampling rate) with a corresponding ranging code at each of a plurality of different offsets from a current estimate of a code delay to generate a plurality of correlation data points; an interpolation filter configured to generate at least one estimated correlation data point that lies between two of the correlation data points based on the current estimate of the code delay. In some cases the ranging code correlation function detection system may also include a discriminator block configured to generate an updated estimate of the code delay based on the at least one estimated correlation data point.

Abstract: 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.

Abstract: A GNSS receiver comprises a memory interface, at least one front end processor and a correlator. The at least one front end processor is configured to receive a GNSS signal, generate a plurality of data samples, form a set from the data samples, and write the set to a memory via the memory interface. The correlator is configured to retrieve from the memory, via the memory interface, a first batch of data for processing, the first batch of data comprising data samples from at least a portion of the set, process the first batch of data, and subsequent to retrieving the first batch of data, retrieve from the memory, via the memory interface, a second batch of data for processing, the second batch of data comprising different data samples from those in the first batch.

Abstract: A GNSS receiver comprises an input, at least one front end processor, and an interference mitigation unit. The input is configured to receive from a wireless communication module a control signal comprising timing information, the timing information indicating one or more transmission times during which the wireless communication module wirelessly transmits data. The at least one front end processor is configured to capture a set of data samples from a received GNSS signal and store the data samples in a memory, each sample captured at a corresponding sample time. The interference mitigation unit is configured to configured to identify data samples of the set of data samples that have a sample time that corresponds with one or more transmission times as candidate samples for interference.

Abstract: A GNSS receiver is configured to operate in a first mode and in a second mode. The GNSS receiver comprises a processor clock, a memory interface, and a correlator. The processor clock is controllable to operate at a first rate and a second rate, wherein the first clock rate is different to the second clock rate. The correlator is configured to retrieve from a memory, via the memory interface, at least a portion of a set of captured data samples, perform one or more correlation operations on the data samples to generate at least one correlation result, wherein the correlator is configured to generate the at least one correlation result at a rate determined by the processor clock. When the GNSS receiver is operating in the first mode, the correlator is clocked at the first clock rate and, when the GNSS receiver is operating in the second mode, the correlator is clocked at a second clock rate.

Abstract: A GNSS receiver comprises a memory interface, one more front end processors, a correlator and a computation unit. The one more front end processors are configured to store, using the memory interface, in a first portion of a shared memory, a set of captured data samples of a received GNSS signal. The correlator is configured to retrieve, using the memory interface, at least a portion of the data samples from the first portion, generate a plurality of correlation results, each correlation result indicating a degree of correlation between the retrieved data samples and a ranging code of a plurality of ranging codes, and store, using the memory interface, the plurality of correlation results in a second portion of the shared memory.

Abstract: A GNSS correlator comprises a buffer and a processing unit. The buffer is configured to store input data representing sample values of a GNSS signal captured over a pre-defined time window. The processing unit is configured to receive one or more correlation parameters in a control signal, and, in a first pass, read the input data from the buffer and perform a first correlation operation on the input data, and, in a second pass, re-read the same input data from the buffer and perform a second correlation operation on the same input data, wherein the second correlation operation is different to the first correlation operation.

Abstract: A ranging code correlation function detection system for use in a global navigation satellite system (GNSS) receiver includes a correlation block to correlate a digitized GNSS signal (e.g. at or above a critical sampling rate) with a corresponding ranging code at each of a plurality of different offsets from a current estimate of a code delay to generate a plurality of correlation data points; an interpolation filter configured to generate at least one estimated correlation data point that lies between two of the correlation data points based on the current estimate of the code delay. In some cases the ranging code correlation function detection system may also include a discriminator block configured to generate an updated estimate of the code delay based on the at least one estimated correlation data point.

Abstract: A first oscillator generates a first frequency. A second oscillator generates a second frequency. A controller determines a difference between the first frequency and the second frequency and determines a non-ideal component of the first frequency in dependence on a temperature response of the first and second oscillators.

Abstract: An input receives a generated frequency having a first frequency component and a second frequency component. A filter block includes filter coefficients describing a relationship between the second frequency component and an environmental characteristic. The filter block predicts the first frequency component based on the environmental characteristic, and updates the filter coefficients based on an offset between the predicted first frequency component and a received frequency corresponding to the first frequency component.

Abstract: A first oscillator generates a first frequency. A second oscillator generates a second frequency. A controller determines a difference between the first frequency and the second frequency and determines a non-ideal component of the first frequency in dependence on a temperature response of the first and second oscillators.

Abstract: A first position of a satellite is calculated at a first time in dependence on received orbit data corresponding to an orbit path of the satellite. An orbit path of the satellite is modeled from the first position at the first time to a second time to determine a second position of the satellite at the second time. A third position of the satellite is then calculated at the second time in dependence on the received orbit data. The second position and third position are compared to determine a validity of the orbit data.

Abstract: An input receives a generated frequency having a first frequency component and a second frequency component. A filter block includes filter coefficients describing a relationship between the second frequency component and an environmental characteristic. The filter block predicts the first frequency component based on the environmental characteristic, and updates the filter coefficients based on an offset between the predicted first frequency component and a received frequency corresponding to the first frequency component.

Abstract: A first position of a satellite is calculated at a first time in dependence on received orbit data corresponding to an orbit path of the satellite. An orbit path of the satellite is modeled from the first position at the first time to a second time to determine a second position of the satellite at the second time. A third position of the satellite is then calculated at the second time in dependence on the received orbit data. The second position and third position are compared to determine a validity of the orbit data.

Abstract: A first position of a satellite is calculated at a first time in dependence on received orbit data corresponding to an orbit path of the satellite. Anan orbit path of the satellite is modeled from the first position at the first time to a second time to determine a second position of the satellite at the second time. A third position of the satellite is then calculated at the second time in dependence on the received orbit data. The second position and third position are compared to determine a validity of the orbit data.

Abstract: A first position of a satellite is calculated at a first time in dependence on received orbit data corresponding to an orbit path of the satellite. Anan orbit path of the satellite is modeled from the first position at the first time to a second time to determine a second position of the satellite at the second time. A third position of the satellite is then calculated at the second time in dependence on the received orbit data. The second position and third position are compared to determine a validity of the orbit data.