Stmicroelectronics (research & Development) Limited

Imagination Technologies Limited

Stmicroelectronics Gmbh

Peter Bagnall

Adrian John Anderson

Philip G Mattos

Philip Mattos

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.

GNSS receiver candidate selection

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.

GNSS correlator

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.

Efficient detection of ranging code correlation function of a GNSS signal

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.

Frequency compensation

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.

Method and apparatus for compensating a frequency generator such as an oscillator for frequency inaccuracies

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.

Signal verification

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.

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Bath, United Kingdom

Peter Bagnall