Various examples of methods and systems are provided for generation of correlated finite alphabet waveforms using Gaussian random variables in, e.g., radar and communication applications. In one example, a method includes mapping an input signal comprising Gaussian random variables (RVs) onto finite-alphabet non-constant-envelope (FANCE) symbols using a predetermined mapping function, and transmitting FANCE waveforms through a uniform linear array of antenna elements to obtain a corresponding beampattern. The FANCE waveforms can be based upon the mapping of the Gaussian RVs onto the FANCE symbols. In another example, a system includes a memory unit that can store a plurality of digital bit streams corresponding to FANCE symbols and a front end unit that can transmit FANCE waveforms through a uniform linear array of antenna elements to obtain a corresponding beampattern. The system can include a processing unit that can encode the input signal and/or determine the mapping function.

Various examples of methods and systems are provided for generation of correlated finite alphabet waveforms using Gaussian random variables in, e.g., radar and communication applications. In one example, a method includes mapping an input signal comprising Gaussian random variables (RVs) onto finite-alphabet non-constant-envelope (FANCE) symbols using a predetermined mapping function, and transmitting FANCE waveforms through a uniform linear array of antenna elements to obtain a corresponding beampattern. The FANCE waveforms can be based upon the mapping of the Gaussian RVs onto the FANCE symbols. In another example, a system includes a memory unit that can store a plurality of digital bit streams corresponding to FANCE symbols and a front end unit that can transmit FANCE waveforms through a uniform linear array of antenna elements to obtain a corresponding beampattern. The system can include a processing unit that can encode the input signal and/or determine the mapping function.

A radar receiver (Rx) receives a reflected wave signal corresponding to a radar transmitting signal having been reflected on a target by using a plurality of antenna system processors (D1 to D4), and estimates an arrival direction of the reflected wave signal. A peak frequency selector (21) selects a peak value of a correlation vector. An adjacent time-frequency component extractor (22) extracts correlation vectors in number of (NE×NT−1) corresponding to NE Doppler frequencies and NT times respectively adjacent to a Doppler frequency and a time giving a peak value. A correlation matrix generating adder (23) generates a correlation matrix corresponding to correlation of the reflected wave signal received by a plurality of receiver antennas on the basis of the (NE×NT) extracted correlation vectors.

A radar receiver (Rx) receives a reflected wave signal corresponding to a radar transmitting signal having been reflected on a target by using a plurality of antenna system processors (D1 to D4), and estimates an arrival direction of the reflected wave signal. A peak frequency selector (21) selects a peak value of a correlation vector. An adjacent time-frequency component extractor (22) extracts correlation vectors in number of (NE×NT−1) corresponding to NE Doppler frequencies and NT times respectively adjacent to a Doppler frequency and a time giving a peak value. A correlation matrix generating adder (23) generates a correlation matrix corresponding to correlation of the reflected wave signal received by a plurality of receiver antennas on the basis of the (NE×NT) extracted correlation vectors.

In an embodiment, a method of operating a radar includes: transmitting a radiation pulse with the radar during an active mode; asserting a sleep flag after transmitting the radiation pulse; turning off a crystal oscillator circuit of the radar after the sleep flag is asserted; clocking a counter of the radar with a low power oscillator during a low power mode after the sleep flag is asserted; asserting a timer flag when the counter reaches a first threshold; and transitioning into the active mode after the timer flag is asserted.

A method for operating a stepped frequency radar system is disclosed. The method involves performing stepped frequency scanning across a frequency range using frequency steps of a step size, the stepped frequency scanning performed using at least one transmit antenna and a two-dimensional array of receive antennas, changing at least one of the step size and the frequency range, and performing stepped frequency scanning using the at least one transmit antenna and the two-dimensional array of receive antennas and using the changed at least one of the step size and the frequency range.

A radar system and method for maintaining radar performance of radar system in jammed environment are provided. The radar system has a main antenna arrangement for transmitting and/or receiving electromagnetic waves. Main antenna arrangement includes at least one main antenna element and at least one main electronics module for transmitting and/or receiving signals to/from at least one main antenna element. The system has auxiliary antenna arrangement for transmitting and/or receiving electromagnetic waves, auxiliary antenna arrangement includes at least one auxiliary antenna element and at least one auxiliary electronics module for transmitting and/or receiving signals to/from the at least one auxiliary antenna element. System has a controller connected to main antenna arrangement and to auxiliary antenna arrangement. Controller is configured to transmit first radar waveform from main antenna element, and transmit second radar waveform from auxiliary antenna element.

A radar system and method for maintaining radar performance of radar system in jammed environment are provided. The radar system has a main antenna arrangement for transmitting and/or receiving electromagnetic waves. Main antenna arrangement includes at least one main antenna element and at least one main electronics module for transmitting and/or receiving signals to/from at least one main antenna element. The system has auxiliary antenna arrangement for transmitting and/or receiving electromagnetic waves, auxiliary antenna arrangement includes at least one auxiliary antenna element and at least one auxiliary electronics module for transmitting and/or receiving signals to/from the at least one auxiliary antenna element. System has a controller connected to main antenna arrangement and to auxiliary antenna arrangement. Controller is configured to transmit first radar waveform from main antenna element, and transmit second radar waveform from auxiliary antenna element.

The invention relates to a measuring system (2) for measuring a measured object, in particular a plastic profile (3), said measuring system (2) comprising: an antenna arrangement (4) made of a plurality of THz transceivers (5) each at times actively emitting a THz transmission beam (6) and at times passively receive reflected THz radiation (11), where said antenna arrangement (4) puts out measuring signals (S1) of the measurements of the THz transceivers (5), an adjustment means (12) for adjusting the antenna matrix (4) into several measuring positions (MP1, MP2, MP3) along an adjustment direction (m1, m2), e.g. on a circular path around the measured object (3), a controller and evaluation device (14) for receiving and evaluating the measuring signals (S1) which is configured in such a way that the measuring signals (S1) of said several THz transceivers (5) in said several measuring positions (MP1, MP2, . . . ) are evaluated by means of an SAR evaluation process and a virtual model (VM) of the boundary surfaces (8) of the measured object (3) is created, and subsequently the controller and evaluation device (14) determines layer thicknesses (d, d4) between the boundary surfaces (8) from the virtual model (VM).

An illustrative example embodiment of a detector device includes a plurality of transmitters and a controller that controls the transmitters to transmit respective signals defined at least in part by a sequence of 2N pulses within a period. N is an integer greater than 1. A first one of the transmitters transmits 2N first signal pulses within the period. Each of the 2N first signal pulses have a first phase. A second one of the transmitters transmits 2N second signal pulses within the period. Each of the 2N first signal pulses is simultaneous with one of the 2N second signal pulses. N second signal pulses have a phase shift of 180° relative to the first phase. Others of the second signal pulses have the first phase. The N second signal pulses having the phase shift are immediately adjacent each other in the sequence.