Glossary
A small, integrated circuit that acts as a computer on a chip, designed to control specific operations within embedded systems.
A specific series of test to ensure that a GNSS product is good enough to be released to the mass market.
A type of non-volatile memory that stores data using magnetic states rather than electric charge, making it fundamentally different from traditional RAM like DRAM or SRAM.
The Japanese SBAS for QZSS. See SBAS
milliWatt
Navigation with Indian Constellation
A type of MOSFET with a laterally diffused structure, used for high power and high frequency applications.
A short-range wireless technology that allows devices to communicate with each other when they are in close proximity, typically a few centimeters apart. NFC works at a centre frequency of 13.56MHz with a 14kHz channel.
A signal that cannot be received directly at the GNSS receiver's antenna, but only a faint signal of it that is reflected by surrounding buildings or attenuated by an obstacle is received. A signal that is received from a reflection and/ or by travelling through an obstacle is referred to as multipath.
Using multipath GNSS satellite signals for the PVT calculation tends to result in poor position accuracy and time accuracy due to errors in the calculation of their pseudoranges and Doppler frequencies. Determining which GNSS satellites are NLOS satellites, masking them appropriately, and using only LOS satellites for the PVT calculation improves the position accuracy and time the accuracy.
A standards organization that develops protocols for communication between marine electronic devices, particularly for navigation and positioning systems.
A crucial component of the ARM Cortex-M processor family, responsible for managing interrupts and exceptions.
A form of memory that retains the stored data even when unpowered.
An original design manufacturer is a company that designs and manufactures products, often based on a client's general specifications, and then sells them under the client's brand name. Essentially, the ODM provides both the design and the manufacturing service.
Similar to an ODM, but only provides the manufacturing service and no design services.Products are still sold under the client's brand name.
An environment unobstructed with buildings, trees or any other structures all around the GNSS antenna. This is the GNSS equivalent of line of sight. Without obstruction or reflection of GNSS satellite signals the positioning result is usually optimal and for this reason, the specifications of all GNSS manufacturers generally recommend placing the GNSS antenna in an open-sky environment.
Third-party companies that provide semiconductor assembly, packaging, and testing services for chip designers and foundries.
A feature of the Galileo satellite navigation system designed to authenticate the navigation data sent to users, ensuring it originates from genuine Galileo satellites and hasn't been tampered with. This helps protect against spoofing attacks, where malicious actors transmit fake satellite signals to mislead receivers.
A fundamental component in electronic devices, acting as the foundation for mounting and connecting electronic components. PCBs provide both physical support and electrical connections for these components.
An amplifier with a programmable gain, which can be modified in a specified range by a dedicated control signal.
An integrated circuit that manages the power supply and consumption of an electronic device or system.
A mechanism in electronic devices that ensures the system starts up in a known, predictable state when power is initially applied or restored after a power interruption.
A method used in satelitte navigation that calculates very precise positions, with errors as small as a few centimeters under good conditions.
A specific type of code used in satellite navigation systems. Each GNSS satellite transmits a unique PRN code, which allows a receiver to identify the satellite and measure the distance to it. A PRN code is a sequence of seemingly random binary digits (0s and 1s) that is used to modulate the GNSS signal. While it appears random, it's actually generated by a deterministic algorithm, meaning it can be precisely reproduced by both the satellite and the receiver.
In GNSS (Global Navigation Satellite System) positioning, a pseudorange is an approximate distance measurement between a satellite and a receiver, calculated by multiplying the time it takes for a signal to travel from the satellite to the receiver by the speed of light. It's called "pseudo" because it's not a true, error-free range, as it's affected by various factors like atmospheric delays and receiver clock errors.
Ensures that the silicon behaves as expected in real-world conditions.
It's a type of analog signal or circuit used primarily in temperature sensing and temperature compensation in integrated circuits.
The core output of a Global Navigation Satellite System receiver. It's the process where the receiver calculates its location, speed, and precise time based on signals received from GNSS satellites. This information is crucial for various applications, from navigation in cars to tracking movements in scientific research.
The three primary sources of performance variation of integrated circuits.
The final stage in product development before mass production begins.
A type of surface-mount semiconductor package, characterized by its flat, leadless design with conductive pads on the bottom surface instead of protruding leads. QFNs are used to connect integrated circuits to printed circuit boards.
QZSS is a satellite-based augmentation system (SBAS) developed by the Japanese government to provide precise positioning services over Japan and the surrounding region. QZSS is designed to complement and enhance the existing global navigation satellite systems (GNSS) such as GPS.
A wide range of frequencies used for wireless communication.
The process of capturing real-world Global Navigation Satellite System signals and then replaying them for testing or simulation purposes.
A measurement of the power level of a received radio signal.
A clock that keeps track of the current time, often used in computers and embedded systems to maintain accurate timekeeping.
A technique that enhances the accuracy of a GNSS system by including real-time corrections from nearby reference stations with a known position. This offers fast convergence and centimeter-level accuracy.
This refers to the part of a device that receives signals. A radio receiver picks up radio waves, while a computer's RX pin receives data from another device.
A type of ADC that converts an analog input signal into a digital output using a binary search algorithm. It’s widely used because of its balance between speed, power efficiency, and resolution.
Satellite bands refer to the frequency ranges within the electromagnetic spectrum that are allocated for satellite communication, navigation, remote sensing, and other satellite-based applications. There are several satellite bands commonly used for these purposes, including:
- L-band: typically range from approximately 1 to 2 GHz, L-band frequencies are commonly used in satellite communication and navigation systems like GPS, GLONASS, Galileo, and others.
- S-band: typically range from 2 to 4 GHz. They are used in various satellite communication systems, weather monitoring satellites, and radar applications.
- C-band: typically range from 4 to 8 GHz, C-band frequencies are extensively used for satellite communication, including television broadcasting, maritime and aeronautical communication, and fixed satellite services.
- X-band: typically range from 8 to 12 GHz. They are commonly used in satellite communication for high-data-rate links, military applications, radar systems (such as weather radar and ground-based surveillance radar), and remote sensing.
- Ku-band: typically range from 12 to 18 GHz, Ku-band is widely used in satellite communication for direct broadcast satellite television, VSAT (very small aperture terminal) networks, broadband internet access, and maritime and aeronautical communication.
- Ka-band: typically range from 26.5 to 40 GHz. They are increasingly utilized for high-throughput satellite communication systems, broadband internet services, and certain types of radar applications.
- V-band: typically range from 40 to 75 GHz. They are being explored for satellite communication systems due to their potential for high-data-rate links, especially for terrestrial backhaul and inter-satellite communication.
A technology that improves the accuracy, reliability, and availability of Global Navigation Satellite System (GNSS) signals, like GPS. SBAS achieves this by broadcasting correction and integrity information via geostationary satellites
A technology where the functionality of RF systems is implemented primarily in software running on general-purpose digital signal processors, field-programmable gate arrays, or software-defined radio platforms. SDR allows for reconfigurable and flexible radio systems that can adapt to different communication standards and requirements.
A synchronous serial communication interface often used in embedded systems to connect microcontrollers with peripheral devices. It's known for its simplicity and speed making it a prime choice for short-distance communications.
A form of computer memory that retains data as long as it is powered, but does not need to be constantly refreshed to maintain it's data.
In contrast to double-sideband, where a signal’s frequency content spans two identical bands on either side of a center frequency (0 or the carrier frequency), single-sideband is a technique to transmit and receive only one of the two bands. Double-sideband communication is less efficient due to redundancy and increased bandwidth.
It is the serial number given to each navigation satellite and each satellite constellation is assigned a non-overlapping numbers. For example, for the GPS satellites, as of November 2020, SVN from 1 to 77 have been issued. Some of these SVNs are operational and others are decommissioned due to the satellite having reached its lifespan. SVN are used by the entities managing the satellite constellations, while users of GNSS receivers use PRN numbers to identify navigation satellites.
A debugging and programming interface for microcontrollers, particularly those based on ARM Cortex cores. It's a streamlined version of the JTAG interface, using only two pins for communication instead of the five typically used in JTAG.
A specific temperature stabilised crystal providing much better frequency stability over temperature variations compared to normal crystals.
A system that digitizes the time difference between two signals.
A method of separating uplink and downlink signals in communication systems by using different time slots.
A specific sequence of bits within the navigation message broadcast by GNSS satellites. The telemetry word is crucial for receiver synchronization, specifically marking the beginning of each subframe within the navigation message.
The cumulative number of seconds in a week starting on Sunday at 00:00:00. It ranges from 0 to 604799, which corresponds to the following Saturday at 23:59:59. After which it restarts at 0 again rollovers to 0 each week on Sunday at 00:00:00. Each GNSS satellite broadcasts the current time using this concept of the TOW expressed in seconds and the week number.
The continuous process of a receiver monitoring and synchronizing with signals from multiple satellites to determine its position and other relevant data.
Time to First Fix
This refers to the part of a device that sends out signals. For example, a radio transmitter sends out radio waves, while a computer's TX pin sends data to another device.
A hardware communication protocol that enables serial data transmission between devices. It is "asynchronous" because it doesn't rely on a shared clock signal to synchronize the data transmission. Instead, it uses predefined baud rates and start/stop bits to manage data flow.
A standardized file format used in low-power digital design to describe power intent—how power is managed in a chip—independently of the functional design.
A standardized methodology used in functional verification of digital hardware designs, especially in SystemVerilog. UVM provides a framework and set of guidelines for building reusable, scalable, and modular testbenches.
An oscillator whose frequency is controlled by an input voltage, used in applications like frequency synthesis and modulation.
The power supply for the analog circuitry in a mixed-signal integrated circuit (IC).
It is the power supply voltage provided to the core logic of a chip — the part that performs the main processing tasks. This voltage is usually lower than the I/O voltage (like VDDIO) to reduce power consumption and heat.
Generic name for supply voltages.
A key component in digital communication systems, especially in error correction. It’s used to decode convolutionally encoded data by finding the most likely sequence of transmitted bits, even in the presence of noise.
Visual Line of Sight
The SBAS for GPS. See SBAS
Wide Area Differential Corrections
Several GNSS express their time system using the aforementioned concept of time of week and week number. The data size to transmit the week number differ for different systems and signals. For example, the GPS and QZSS L1C/A signals use a 10bit data size to transmit the week number; providing a week number from 0 to 1023. The week number that follow week 1023 is again week 0. This event is called week number rollover.
After a week number rollover occurs, GNSS receivers without special measures may output a date 1024 weeks out of date. Our GPS/GNSS receivers have been designed to deal with a GPS/ QZSS week number rollover and will continue to display the correct date after such an event. However, the range of date that can be properly converted is still up to 1024 weeks.
Depending on the product, this date, until which the correct date can be computed independently, is different. Please refer to the product specifications for details. Once this limited period of time has past, upon a restart without backup, the GPS/ GNSS receivers may display a date 1024 weeks or multiple of 1024 weeks out of date. In this case it is possible to set the correct date by sending a command to the GNSS receivers or by enabling the use of GLONASS and/ or Galileo satellites if supported. In the case of a continuous operation, our GPS/ GNSS receivers correctly maintain the current date and time upon week number rollovers.
A type of semiconductor packaging where the integrated circuit is packaged directly on the wafer, resulting in a package that is roughly the same size as the die itself
An informal abbreviation used to specifically refer to a quartz crystal oscillator.