Nordnav Technologies Ab

Other

Cambridge Silicon Radio Limited

Christian Stahlberg

Per-Ludvig Normark

Alexander Mitelman

James Burgess Tidd

Robin Hakanson

Fredrik Lindstrom

Thomas Renstrom

A GNSS receiver design is tested, which design includes software for generating position/time related data (DPT) based on raw digital data (dRAW) when the software is executed in a processing unit of the receiver. GNSS signals (SRF) are received via a radio frequency input device while moving the radio frequency input device along a route trajectory. The received GNSS signals (SRF) are fed to a radio-frequency front end of a Representative example of a receiver unit built according to the design to be tested. The radio-frequency front end produces raw digital data (dRAW) representing the received GNSS signals (SRF), and the raw digital data (dRAW) are stored in a primary data storage as a source file (Fsc). The source file (Fsc) is read from the primary data storage, and the source file (Fsc) is processed by means of the software to generate at least one set of position/time related data (DPT). Each set of position/time related data (DPT) is stored to a respective result file (Fres), and the result file(s) (Fres) is/are evaluated against reference data (Dref) to determine the performance of the design.

GNSS receiver design testing

A digital processing unit for use in a spread spectrum signal receiver, the digital processing unit being adapted to receive an incoming stream of data samples and in response thereto produce a decoded signal, the digital processing unit comprising a correlation module adapted to correlate data blocks formed from the incoming stream of data samples with a local code replica segment to produce a first number of intermediate accumulation results and an aggregation module adapted to receive the first number of intermediate accumulation results and to combine the first number of consecutive ones of said intermediate accumulation results to form a target number of aggregated accumulation results, said target number being less than or equal to the first number.

Software based spread spectrum signal processing

A proposed data processing device includes at least two processor units, which each is adapted to process digitized precorrelation navigation satellite signal data as well as to process alternative data and/or signals relating to at least one function being uncorrelated with the satellite signal data. The device includes at least one data buffer adapted to store data sets, where each set includes a number of instances of the satellite signal data. A control module in the device controls execution of a processing job with respect to a stored data set by allocating individual processing tasks to at least one of the at least two processor units based on a current processing load on each processor unit.

Software-based spread spectrum signal processing

A software correlator comprising: a partitioning module adapted to divide a number of the received data samples into a first number of data blocks; a first correlation module adapted to correlate each of the data blocks with a respective local code replica segment to produce a first number of intermediate accumulation results; an aggregation module adapted to combine a number of consecutive results of the intermediate accumulation results into a target number of aggregated accumulation results, the target number expresses a number of discrete carrier values in a carrier vector that represents a Doppler shift of the at least one spread spectrum source signal relative to a downconverting frequency for this signal; and a second correlation module adapted to correlate the aggregated accumulation results with the carrier vector to produce the decoded signal, which is compensated for the Doppler shift relative to the downconverting frequency.

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Sollentuna, Sweden

Christian Stahlberg