Abstract: The present disclosure provides an authentication method for a satellite-based navigation system that in some implementations includes: obtaining, by an authentication server, a plurality of message authentication bundles from a plurality of reference receiver stations, each message authentication bundle comprising at least one hash for authenticating a corresponding SNS message received by a respective reference receiver station from at least one satellite of the SNS; inserting, by the authentication server at least a subset of the hashes of the obtained message authentication bundles into a probabilistic data structure (PDS), which forms at least a part of a validation filter for authenticating a corresponding subset of SNS messages; and distributing the validation filter to at least one receiver-side device.

Abstract: A method and apparatus are provided for calculating a position of a first device relative to a reference device for a current time. The method comprises obtaining first reference GNSS measurements, made at the reference device for a first time, obtaining the position of the reference device for the first time, obtaining first device GNSS measurements, made at the first device for the current time, and calculating a first relative position between the first device at the current time and the reference device at the first time. The method further comprises obtaining second reference GNSS measurements, made at the reference device for a second time subsequent to the first time, calculating a position change of the reference device from the first time to the second time, and calculating the second relative position between the first device at the current time and the reference device at the second time.

Abstract: A method for position estimation in a positioning system includes receiving, by locator devices, positioning signals from a mobile device, generating positioning information with associated synchronization identifiers based on the respective received positioning signals, and providing the positioning information with the associated synchronization identifiers to a positioning engine. The positioning engine compiles a set of related positioning information selected from the provided positioning information based on a similarity measure of the associated synchronization identifiers, and determines an estimated position of the mobile device based on the set of related positioning information.

Abstract: A method for determining a protection level of a position estimate using a single epoch of GNSS measurements, the method includes: specifying a prior probability density P(x) of a state x; specifying a system model h(x) that relates the state x to observables z of the measurements; quantifying quality metrics q associated with the measurements; specifying a non-Gaussian residual error probability density model ƒ(r|?, q) and fitting model parameters ? using a set of experimental data; and defining a posterior probability density P(x|z, q, ?); estimating the state x; and computing the protection level by integrating the posterior probability density P(x|z, q, ?) over the state x.

Abstract: A method and apparatus are provided for processing a GNSS signal received at a receiver. The GNSS signal may be tracked in different ways in two or more respective operation modes. A first epoch is processed according to a first operation mode. In this mode, a carrier phase of a local carrier signal is controlled to track the carrier phase of the GNSS signal using a phase locked loop. A second epoch is processed according to a second operation mode. In this operation mode, the carrier phase is controlled based at least in part on at least one Doppler estimate. The at least one Doppler estimate depends on inertial measurements made at the receiver.

Abstract: A method for determining positions of a plurality of terminal devices by a server includes receiving by the server from the terminal devices, each allocated to one of predetermined one or more clusters, first global navigation satellite system (GNSS) information according to predetermined transmission patterns of the terminal devices, and second GNSS information at random. The method includes collecting context related data from one or more context sources, and updating, by the server, the set of predetermined clusters based on a part of the context related data and the first and the second GNSS information and a predetermined criteria of cluster's level of accuracy. The method further includes determining, by the server, based on the first and the second GNSS information and on the updated clusters, respective positions of the clusters and individual positions of the terminal devices according to the respective positions of the clusters.

Abstract: A method and apparatus are provided for demodulating an L1S signal from a satellite in the Quasi-Zenith Satellite System (QZSS). The method comprises tracking another L1 signal transmitted by the satellite, and predicting, based on the tracking parameters of the other L1 signal, one or more parameters of the L1S signal. The L1S signal is demodulated based on the one or more predicted parameters.

Abstract: The present disclosure relates to a method for performing key management for a plurality of communication devices, each of the plurality of communication devices being configured to perform wireless communication using a first wireless communication technology. The method comprises establishing, by at least one of the plurality of communication devices, a first secure connection with a key management service using a second wireless communication technology. The method further comprises negotiating, by the at least one communication device with the key management service using the first secure connection, first authentication information comprising a first authentication bundle for secure communication and/or data protection on the first wireless communication technology.

Abstract: Methods and devices for odometry are disclosed. A previous position estimate and a current position estimate for a device are obtained. A current velocity estimate for the device is also obtained. A first distance estimate is calculated based on the position estimates, and a second distance estimate is calculated based on the velocity estimate. These two distance estimates are combined to generate a combined or hybrid distance estimate for the distance travelled by the device.

Abstract: An antenna includes an optically transparent substrate layer having a first surface and an opposing second surface; a radiating element having a first mesh structure and disposed on the first surface of the substrate layer; a ground plane having a second mesh structure formed on the second surface of the substrate layer; at least two feed lines configured to connect the radiating element to an external circuit; and at least two stubs connected to the radiating element.

Abstract: A static GNSS receiver, a base station module, a method of estimating a position of a static GNSS receiver, and an associated computer program are provided. An example method includes calculating a first difference between a first pseudorange and a second pseudorange, each made at a first time. A second difference between a third pseudorange and a fourth pseudorange, each made at a second time, is calculated, with the second time different to the first time. A position of the GNSS receiver is calculated based at least in part on the accumulated pseudorange differences.

Abstract: Methods and apparatus are disclosed for assisting in the determination of the position of a wireless communication device. One wireless communication device is provided comprising a transmitter configured to broadcast a direct sequence spread spectrum reference signal in a predefined ISM band. Another wireless communication device is provided comprising a receiver that is configured to receive direct sequence spread spectrum reference signals in the predefined ISM band. The same transmitter and receiver are used to communicate between the respective wireless communication devices and one or more base stations in a wireless infrastructure network (of which each wireless communication device is a part).

Abstract: In one embodiment a tracking circuit for tracking a frequency of a sweeping signal component in an input signal comprises an input for receiving the input signal (Sin) comprising the sweeping signal component and a noise component, a mixer coupled to the input and configured to mix the input signal with a replica signal and therefrom provide a residual input signal, a low-pass filter coupled downstream of the mixer, a discriminator circuit coupled downstream of the low-pass filter, a loop filter coupled downstream of the discriminator circuit and configured to provide a frequency control value, and a replica signal generator circuit coupled downstream of the loop filter and configured to provide the replica signal with a frequency adjusted based on the frequency control value, wherein the frequency of the replica signal represents an estimation of a frequency of the sweeping signal component propagated to a current time unit of the input signal.

Abstract: A method and apparatus are provided for processing GNSS measurements to infer state information. An example method includes obtaining one or more residual error models for the plurality of GNSS measurements. The one or more residual error models describe a probability distribution of errors in each of the GNSS measurements. The method further includes inferring the state information based on the one or more residual error models. The GNSS measurements include at least one carrier phase measurement. The residual error model for the at least one carrier phase measurement is cyclic, such that errors in carrier phase that are separated by an integer number of cycles are regarded as equivalent. The probability distribution for the at least one carrier phase measurement comprises a function having a continuous first derivative, for example, a continuous first derivative at a phase boundary between successive cycles.

Abstract: A method and apparatus are provided for demodulating a B2b signal from a satellite in the BeiDou Navigation Satellite System. The method comprises tracking a first signal transmitted in a first GNSS operational band by the satellite, to estimate one or more parameters of the first signal; predicting, based on the estimated one or more parameters of the first signal, one or more parameters of the B2b signal transmitted by the satellite; and demodulating the B2b signal to obtain data bits of a data message modulated on the B2b signal by the satellite. The demodulating is based on the one or more predicted parameters of the B2b signal.

Abstract: A method and apparatus are provided for calculating a position based on Global Navigation Satellite Systems (GNSS) signals. The method includes estimating a first state vector comprising a first set of float carrier range ambiguities using a first estimator, basedon first observations of the GNSS signals; and estimating a second state vector comprising a second set of float carrier range ambiguities using a second estimator, based on second observations of the GNSS signals. It further comprises fixing one or more first carrier range ambiguities, using a first strategy, based on the first set of float carrier range ambiguities; and fixing one or more second carrier range ambiguities, using a second strategy, based on the second set of float carrier range ambiguities. The first strategy for fixing the one or more first carrier range ambiguities is different from the second strategy for fixing the one or more second carrier range ambiguities.

Abstract: In a method for protecting payload data transmitted via a one-to-many communication channel from a provider device to at least one receiver device a public key set (PK) supporting asymmetric bilinear pairings is generated. A number of receiver device keys (DKi) that are generated based on the public key set (PK) are distributed to respective devices including the at least one receiver device. A provider key (K) is generated based on the public key set (PK) and inter alia on an encryption random number (t) and stored in the provider device. An envelope (ENV) is generated based on the public key set (PK) and on the encryption random number (t) and is distributed, via the one-to-many communication channel, to the respective devices including the at least one receiver device. The at least one receiver device generates a receiver key, which corresponds to the provider key, based on the distributed envelope (ENV) and the distributed receiver device key (DKi).

Abstract: In a method for determining a 3D directional vector between a sending device and a receiving device, the receiving device comprises at least two antenna arrays that each comprise a plurality of linearly arranged antenna elements that are aligned to different orientations.

Abstract: A GNSS receiver, a method of estimating position, and an associated computer program are provided. An example method includes calculating a first (full) position solution based on pseudorange measurements made at a first time. One or more position updates are then calculated based on the first position solution, using delta carrier range measurements which compare first carrier range measurements, made at the first time, with second carrier range measurements, made at a second time. When calculating the one or more position updates, the delta carrier range measurements may be corrected to compensate for satellite motion between the first time and the second time. Corrections may also be made to compensate for changes in ionospheric delay.

Abstract: In an example embodiment, a method for adjusting a phase of a carrier replica signal includes receiving, by a tracking loop, a digital baseband signal, generating within the tracking loop the carrier replica signal, generating within the tracking loop a sequence of samples from the digital baseband signal and the carrier replica signal, and controlling a phase of the carrier replica signal depending on the sequence of samples. The example method further includes receiving a trigger signal indicating an upcoming phase shift of the digital baseband signal, blanking the tracking loop and controlling the phase of the carrier replica signal using a constant value, determining a magnitude of the phase shift, adjusting the phase of the carrier replica signal using the determined magnitude of the phase shift, and un-blanking the tracking loop and controlling the phase of the carrier replica signal depending on the sequence of samples.