This article explains abbreviations from the areas of measurement, testing, simulation and signal processing: from AFE and FEC to FFT and LXI to beyond OFDM and VNA.The following compilation contains definitions and explanations for abbreviations and terms from the areas of measurement, testing, simulation and signal processing.Links to topic-related specialist articles as well as to further web pages provide many more details and inform about the state of the art.The analog front end (AFE) is an industry-wide term for the first stage of a sensor signal processing chain.Signal processing in communications engineering modulates the amplitude of a frequently high-frequency signal (carrier) with a low-frequency useful signal (AF) in order to transmit analogue or digital information.The simple analog modulation method is susceptible to interference.Colloquially, AM is often used as a synonym for short/medium/long wave broadcasting.Active Noise Control/Cancellation/Reduction.Anti-noise or active noise compensation compensates for ambient noise (airborne noise) through destructive interference using artificially generated noise - an exact duplicate of the disturbing noise, but with opposite polarity.Engine and driving noise can be compensated for in the vehicle cabin - also in the exhaust, hands-free systems improve intelligibility and in the area of structure-borne noise (destructive) vibrations can be suppressed.In the consumer sector, ANC headphones/earbuds are important products that systematically block out ambient noise.Speech recognition systems often perform better when the microphone used has a high acoustic overload point (AOP).The AOP is defined as the sound pressure level (SPL) at which the distortion factor exceeds 10 percentage points, measured in dBSPL (Decibel Sound Pressure Level).A high AOP ensures that algorithms are better able to suppress interference signals and receive a relatively distortion-free speech signal.Learn more about this in the article Digital listening with MEMS microphones.Amplitude shift keying (ASK) is one of the digital modulation methods in communications engineering.The amplitude of a carrier is changed in leaps and bounds in order to transmit different values.The simplest form of amplitude keying is on-off keying (OOK), in which the carrier is turned on and off to transmit a 1 or 0.Different amplitude jumps allow several bits to be encoded per symbol step (four different amplitudes represent two bits: 00, 01, 10 and 11).Higher data rates use multiple carriers in parallel.In general, ATE includes automated metrological equipment for testing during production in the chip and electronics industry.For example, integrated circuits are tested using wafer, chip or module tests, soldered analogue components or printed circuit boards.Test contents are contact test, parameter test, function test.More complex test strategies and greater test depth can be implemented with the in-circuit test (ICT) and the boundary scan.The underlying digital volume tomography (DVT) is a three-dimensional, imaging tomography method using X-rays.The false alarm rate (FAR) is a measure of the quality of a radar system.Echo signals occur statistically distributed and lead to the detection of flat (non-existent) objects.The false alarm rate is the average number of false targets that can be detected at the receiver output in a certain time, for example per antenna revolution or per pulse repetition period (PRT).Modern radar systems regulate to a constant false alarm rate (CFAR) depending on the environmental conditions.They use Sensitivity Time Control (STC), which affects receiver dynamics and is also known as GTC (Gain Time Control).The resulting dynamic range compression causes near-end echo attenuation and thus improves object detection.Modern drones also orient themselves using radar.Computed tomography is an imaging method in radiology.In contrast to X-ray tomography, computed tomography uses a computer to generate cross-sectional images calculated from the absorption values of X-ray signals passing through the body.Digital sectional images are reconstructed by computer-based evaluation of a large number of X-ray images of an object taken from different directions.Alternative names are CT scan, CAT scan (from computer-assisted tomography or computed axial tomography) or tomography.On-premises cloud solutions in medicine aim to make the handling of large amounts of data and complex calculation software and computers generally available in the medical field.CW means here: permanent beam emission of a radar/lidar system (as opposed to pulsed radar/lidar)(Packet) data acquisition, mostly as part of XCP.The digital shaping of the emitted beam of rays makes it possible to send and receive (radar) waves from different directions at the same time.The three-dimensional, imaging computed tomography (CT) procedure uses X-rays and is mainly used in ear, nose and throat medicine, oral, maxillofacial and maxillofacial surgery and dentistry.Hounsfield-calibrated devices are called "Cone Beam CT" (CBCT) in Anglo-American literature.This technique opens up completely new avenues, so that the assessment of soft tissue structures and virtual endoscopy is now also possible.The Hounsfield scale describes the attenuation of X-rays in the tissue in CT.The resulting greyscale images allow tissue types to be assigned and thus pathological deviations can be identified.The density wavelength multiplex method is currently considered to be the most powerful multiplex method.Here the wavelengths (spectral colors) used for transmission in the fiber optic cable are very close together.The frequency range of the wavelengths is usually in the C or L band with a frequency spacing of 0.4 nm (50 GHz) to 1.6 nm (200 GHz).These small frequency distances can only be achieved with temperature and wavelength-stabilized lasers (thermostated DFB laser diodes) and high-quality filters.Data transmission rates of up to 100 Gbit/s per channel with a maximum of 80 channels are possible, the combination of the C and L band makes 160 channels usable.Forward error correction (also known as error detection and correction, EDAC) is a method of reducing the error rate when storing or transmitting digital data.In a transmission system, the sender encodes the data to be transmitted in a redundant manner so that the receiver can detect transmission errors without asking the sender and correct them up to a certain degree of error.Forward error correction is used in compact discs (CD), digital television (DVB) and mobile communications.Definition: The Fourier transformation describes a continuous analog signal of any form (time domain) based on its sinusoidal harmonics (frequency domain) – i.e. breaks down the signal into its frequency components.This representation of analog signals in the frequency range is essential for the processing of digital systems.Realistically, however, analog signals can only be sampled discretely, so that the discrete-time FT (DFT) is used within a sampling time window with n samples.The FFT is a fast and more efficient form of the DFT and has numerous applications in mobile radio technologies and in measurement technology.Signal processing in communications engineering modulates a frequently high-frequency carrier signal by changing its carrier frequency (detuning the oscillator) using a low-frequency useful signal (AF) in order to transmit analogue or digital information.The analog modulation method is robust against interference.Colloquially, FM is often used as a synonym for VHF radio broadcasting.Field-oriented control/regulation or vector control controls electric motors such as asynchronous induction machines (IM), also known as squirrel-cage or squirrel-cage rotors, or permanently excited synchronous machines (PMSM, BLDC, reluctance motor).The main feature of vector controls is the conversion of the three-phase stator current system into a two-axis orthogonal system, whose two-dimensional current space vector is used to control the magnetic flux density and rotor torque.This fact is a clear difference to the scalar control based on the three-phase system such as voltage to frequency in the classic inverter.In vector control, a DSC (digital signal controller) takes on the two-stage transformation to convert the three AC phases into two control variables that are constant over time for a PI control algorithm.The controller output signals must then be correspondingly inverse transformed in two stages before they can drive the three-phase inverter driver stage.In communications engineering, this modulation method is used to transmit digital signals, for example by radio.Like analog frequency modulation (FM), FSK is immune to interference.The modulation is done by varying a sinusoidal carrier frequency between a set of different frequencies that correspond to each transmit symbol.The simplest option is to switch between different frequency generators simultaneously.Because these do not have a synchronous phase relation to one another, a discontinuous signal curve results at the switching times, which results in an undesirably high bandwidth requirement (hard FSK).An improvement to the modulator is continuous phase frequency shift keying (CPFSK) switching, which results in a smooth waveform and saves bandwidth.An FSK modulator with an upstream Gaussian filter (GFSK) shapes the square-wave bit signal into bell-shaped pulses with a Gaussian curve.This results in the lowest time bandwidth requirement (soft FSK).However, the non-abrupt switching of the transmission frequencies also causes intersymbol interference, which can be corrected at the receiver.With this extended frequency shift keying, the FSK modulator is preceded by a Gaussian filter.The steep edges of the digital useful signal (rectangular bit data) become flatter because the high-frequency components of the signal are omitted, which saves bandwidth.However, the soft frequency shift keying also causes increased intersymbol interference.With the GSM mobile communications standard (Global System for Mobile Communications), the very similar GMSK method (Gaussian Minimum Shift Keying) converts the bit signals from 3.7 µs wide rectangles into 18.5 µs long Gaussian pulses.The demodulator can use error correction to compensate for the superimpositions (intersymbol interference) that sometimes occur as a result and the resulting misinterpretation of adjacent bits.The HCI communicates register-level status and control functions between the host controller of a hardware interface (FireWire, USB, Bluetooth) and the appropriate protocol stack.With Bluetooth, the HCI forms a link between the RF hardware module and the Bluetooth protocol stack.The HCI interface manages the connection parameters between the communication partners and displays the device settings.From the Bluetooth protocol stack, it then goes on to the Bluetooth application via the Bluetooth Embedded Control Interface (BECI).Many other naming conventions are common for the term HCI: Host adapter, Advanced Host Controller Interface (AHCI) for SATA, Enhanced Host Controller Interface (EHCI) for USB 2.0, Non-Volatile Memory Host Controller Interface (NVMHCI) for PCI Express (PCIe) , Open Host Controller Interface (OHCI) for USB 1.1, Universal Host Controller Interface (UHCI) for USB1.x, Wireless Host Controller Interface (WHCI) for wireless USB, Extensible Host Controller Interface (XHCI) up to USB 3.1, Virtual Host Controller Interface (VHCI) for USB/IP.for example, high light-dark dynamics in sensorsThe in-circuit test is a test method for electronic assemblies and printed circuit boards in electronics production.A special test adapter contacts the assembled printed circuit board and tests for errors in the conductor path, soldering errors and component errors, records analog component parameters and can stimulate and test digital circuits.— Extremely small and complex circuit designs often do not allow physical access to certain circuit points.Multilayer boards with a high component density or highly integrated components can then be tested using boundary scan.The IEEE 1149.1 test method implemented by JTAG (Joint Test Action Group) uses separate IC pins to inject test signals through predefined paths into the circuit under test.In normal operation, the test pins are inactive and there is no difference to ICs without boundary scan functionality.All boundary scan cells are linked in series to form a chain that encompasses the entire I/O structure of the integrated circuit.The IC has at least four dedicated control and data pins.In special cases, even signal generators and virtual oscilloscopes can be activated for the test in complex mixed-signal ICs.LEM is a Swiss manufacturer of measurement technology and components, where LEM stands for Liassons Electroniques-Mécaniques.Standard for networking measuring devices via EthernetA MAF sensor is known in German as an air mass sensor.boost pressure;a MAP sensor is used to measure the absolute pressure at the intake manifold of a vehicleSuch micromechanical systems are, for example, semiconductor sensors in chip size, which can measure acceleration, pressure or sound waves.There are also MEMS sound transducers or oscillators.Without MEMS, gyroscopes in cars would not be suitable for the masses, nor would ESP or DLP projection systems.MID is another name of the European Directive 2004/22/EC on measuring instruments.This serves to harmonize the legal regulations on the provision of measuring devices with verification in the EU.Types of meters include, but are not limited to, electricity meters, flow meters, taximeters, scales, and exhaust gas analyzers.More details on the MID policy at Wikipedia.Analog modulation methods: AM |FM |PM |vm |SSB |SSBSC |DSBSC Digital modulation method: ASK |FSK |GFSK |PSK |QPSK |QAM |APSK |OFDM |DMT |TCM |VSB pulse modulation method: PWM |PAM |PFM |PPM (1) |PPM (2) |PCM frequency spread modulation method: FHSS |DSSS |THSS |CSSEngine position sensor is a term coined by Hella in the field of EPS.The underlying measurement method is magnetic resonance imaging.Mid-range radar works in vehicles at around 77 GHz and achieves a range of around 200 m with a horizontal opening angle of around 70°.Using special modulation methods such as FM-FSK, MRR achieves effective interference and interference suppression.The wireless energy transmission through inductive coupling of two air coils works in resonance mode even with weak coupling and over long distances.A4WP (now the Air-Fuel Alliance) defined the Rezence interface standard for charging small battery-operated devices (e.g. smartphones), which can wirelessly transmit electrical energy of up to 50 W at distances of up to 5 cm via magnetic resonance.The Power Transmission Unit (PTU) can simultaneously power up to eight Power Receiver Units (PRU) and operates at 6.78 MHz.Highly Resonant Wireless Power Transfer (HR-WPT) is used to charge electric vehicles.Magnetic resonance tomography is an imaging method (also known as Magnetic Resonance Imaging, MRI) and is primarily used in medical diagnostics to display the structure and function of tissues and organs in the body.The method, also known as nuclear spin tomography, is physically based on nuclear magnetic resonance (NMR).The MRT system (also called nuclear spin tomography or MRT device) generates very strong alternating magnetic fields in the radio frequency range, with which certain atomic nuclei (usually the hydrogen nuclei/protons) in the body are resonantly excited, which induces an electrical signal in a receiver circuit.No harmful X-rays or ionizing radiation is generated in the device, but the effects of the alternating magnetic fields on living tissue have not been fully researched.As a special form of FDM, orthogonal frequency multiplexing is a special implementation of multicarrier modulation and uses multiple orthogonal carriers for digital data transmission.The useful information to be transmitted with a high data rate is divided into a number of partial data streams with a low data rate.These are then each modulated individually, for example using quadrature amplitude modulation (QAM), and the modulated RF signals are then added.In order to be able to distinguish between the individual signals during demodulation in the receiver, it is necessary for the carriers to be orthogonal to one another in the function space.The simplest form of amplitude shift keying (ASK) is on-off keying, where the carrier is turned on and off to transmit a 1 or 0.With the analog modulation method of pulse amplitude modulation, the analog message signal is sampled regularly, its signal level is measured and pulses are generated at the same rhythm, the amplitude level of which corresponds to the signal level.The PAM signal is time-discrete and value-continuous.Transmission systems with analog multiplex methods can transmit PAM pulses of other message signals in the pulse pauses.PAM is sensitive to interference and unsuitable for longer distances.Pulse amplitude modulation is the precursor to pulse code modulation (PCM), which also quantifies the amplitude values as a digital bit sequence.The pulse modulation process converts a time- and value-continuous analog signal into a time- and value-discrete digital signal.In addition to PCM, pulse amplitude (PAM), duration, phase, and frequency modulation are digital modulation schemes with varying degrees of resilience to systematic or random interference.The disadvantage of PCM coding is the high data transfer rate required (around 1.4 Mbit/s for audio CDs).With the extended PCM method, Differential Pulse Code Modulation (DPCM), only the difference to the previous value is transmitted, which allows smaller word lengths and higher compression.The delta modulation represents a special case of the DPCM and reduces the quantization to only 1 bit.The digitized telephone networks are the largest area of application for PCM technology.Positron emission tomography is an imaging method used in nuclear medicine.PET creates sectional images of living organisms by making the distribution of a weakly radioactively marked substance (radiopharmaceutical) visible in the organism and thus depicting biochemical and physiological functions (functional imaging).Today, PET is almost exclusively performed in combination with CT or MRI as a hybrid procedure and is also used in cancer diagnosis.On-premises cloud solutions in medicine aim to make the handling of large amounts of data and complex calculation software and computers generally available in the medical field.In signal processing, pulse frequency modulation (PFM) is also known as pulse density modulation (PDM) or delta modulation and is a variant of differential pulse code modulation (DPCM) in which the pulse-coded signal on the transmission channel can only have two logic levels.The process converts an analog signal curve into a signal that, like a digital signal, can only have two discrete values, but its pulse spacing can be changed continuously, i.e. not in a time-discrete manner.The larger the input signal to be converted, the more pulses of constant duration are generated per time span.Pulse width modulation (PWM) is related to the process, although the pulse width is varied at a constant frequency.In power electronics, pulse frequency modulation is used to control switching regulators and DC/DC converters.The AN6608 application note for the MAX17503 DC/DC converter clearly compares the three operating modes CCM, DCM and PFM with a signal curve.an optical sensor that works according to the time-of-flight method, which emits modulated light itself and then measures the transit time (time of flight).Enables highly selective, interference-free work.See also ToF sensorPrinciple for determining the heart rate by changing the heart ratePhase shift keying is a digital modulation method in communications engineering.In this case, a sinusoidal carrier oscillation is shifted into discrete phase steps by the digital data stream to be transmitted.The binary PSK (BPSK) or 2-PSK (phase shift in the time signal by 180°) transmits one bit per symbol.Due to its low spectral efficiency, it is only rarely used in practice, but it forms the basis of digital modulation processes based on it. With quadrature phase shift keying (QPSK) or quadrature amplitude modulation (QAM), the amplitude of the carrier oscillation is modulated in discrete steps in addition to the phase position.Electronic communications technology uses this modulation method for HF signal transmission - usually by radio - and combines amplitude and phase modulation.The term IQ, composed of the English terms “in-phase” and “quadrature”, is also common.The principle uses two sinusoidal carrier waves with a phase shift of 90° to each other, which represent the in-phase and quadrature components of the resulting RF signal.Physically, the radio signal is always analogue, the signal processing (modulation --> transmitter, interpretation --> receiver) is now digital as far as circuitry allows.Most of the common radio protocols on the market such as WLAN, Bluetooth, Zigbee, Z-Wave use analog-based RF architectures.Their power consumption is unfavorable for battery-based applications, especially at data rates above 1 Mbit/s.Learn how the digital form of QAM is done more efficiently in polar coordinates.The signal-to-noise ratio (SRV, S/R, SNR, S/N, also signal-to-noise ratio) describes the technical quality of a useful signal (speech, video) that is superimposed by a noise signal.The static variable in dB (decibels) is defined as the ratio of the mean power of the useful signal to the mean noise power of the interfering signal.The SNR plays an important role in high-frequency, measurement and communications technology and acoustics (MEMS microphones), but also in many other areas of automation technology or signal and image processing.Related quantities are peak signal-to-noise ratio (PSNR), carrier-to-noise ratio (C/N), and carrier-to-interference ratio (C/(I+N) or C/I).Very outdated designation for SNR.Semiconductor based lidar (as opposed to a rotating cylinder lidar)The system currently being tested, analogous to DuTThis test method runs through two temperature extremes.It is an environmental stress test used in both product reliability evaluation and manufacturing to detect early latent failures by causing thermal fatigue failures.Diagram editor for tests, element of a test environmentIn the context of signal analysis, the harmonic distortion is an indication to quantify the size of non-linear distortion of a signal.Various definitions relate either to the ratio of a power variable or to the time profile of an electrical voltage in the form of an amplitude ratio.The THD is defined as the ratio of the total power Ph of all harmonics to the power of the fundamental P1.Alternatively, in audio engineering (article MEMS microphone) or in electrical power supply networks (article portable oscilloscope) amplitude ratios are set in relation and referred to as THD.Distortion is similarly specified as an amplitude ratio, but uses the rms value of the entire signal as a reference and not just the rms value of the fundamental.In the field of signal processing, this transit time measurement method uses a modulated carrier signal to determine the distance to the reflection point.Measurement signals are, for example, ultrasonic parking distance control (PDC)), radio waves (radar, mobile phone navigation, keyless entry) or laser light (lidar, PMD).ToF is highly selective and interference-free.A TTE (Test Data Editor for Tests) is an element of a test environment.Ultra high resolution video signals, mostly 2160 x 3840 pixels;old name: 4kvirtual software development kit containing a virtual prototype as a hardware targetvirtual ECU, sometimes also vECU or V-ECUvirtual functional bus as part of AutosarA VIT is used for integration tests and testing of control units and systems in a simulated environment.The extensive HIL test environment combines remaining bus simulations, feeding in real measurement recordings and, for example, a PXI platform for test, measurement, control and regulation applications.Such a measuring device helps to characterize electronic circuits, components or lines as a kind of black box from the external connections.It is considered as a quadrupole (systems theory) and the four S-parameters (S11, S12, S21 and S22) are measured.To do this, a VNA feeds a high-impedance broadband HF test signal into the circuit or a component via a coupling network and measures the frequency-dependent current and voltage curve.The S-parameters provide the frequency and phase response of the test object and allow conclusions to be drawn about the transmission and reflection behavior.This is particularly important when adapting antennas in HF technology, so that transmission amplifiers are not damaged by excessive reflected power and receivers receive sufficient input levels.The cut-off frequency of VNAs is now well above 50 GHz.A virtual test or a virtual test system allows devices or functions to be tested by simulation at an early stage of development.This also saves effort, time and money and protects the test object.Dynamics compression is generally a reduction in the range of signal amplitude and frequency.In the case of acoustic signals (microphone signal, sound recording), signal processing reduces the volume depending on the frequency.The focus is on human auditory psychology (intelligibility in speech signal transmission, hearing aids), in amplifier and loudspeaker technology overload protection for the technology can be implemented at high signal levels and data and redundancy reduction is possible with digital signal transmission.In hearing aids, WDRC uses progressively less gain as volume increases, making soft speech audible or allowing louder sounds to remain comfortable.Universal communication solution (in the field of measurement technology), in which the "X" stands for an exchangeable or variable transport layer.Successor to CCPModulation methods in communications engineering --> see PSK.