Aspects of the present disclosure are directed to radar transmissions and related componentry. As may be implemented in accordance with various embodiments, radar signals are generated and transmitted using both scanning and fixed beam analog signal codes concurrently/as combined for each radar signal. Reflections of the radar signals from a target are processed for ascertaining positional characteristics of the target.

Techniques and systems are described for Spatial-Block Code Division Multiplexing (CDM) for MIMO waveforms. A radar system includes multiple transmitters, receivers, and phase shifters. Electromagnetic (EM) signals are transmitted and received in a Spatial-Block CDM scheme. Each spatial block has multiple slots outnumbering the channels. In addition, each slot corresponds to a specific code of phase shifts applied across the channels by the phase shifters during that slot. Fast-Fourier Transformations are applied to reflections of the EM signals to generate complex observations at each of the channels during each slot. Based on the observations, whether a Doppler phase shift exists between two slots can be determined based in part on whether the phase shift has one or multiple possible values. The techniques allow velocities to be resolved, despite a mixed-Doppler interval detected. Analog beamforming is supported; slots can be directed at particular angles to change gain in a field of view.

A method of generating a reference signal for transmission over a wireless communication channel comprises generating a first signal of a first characteristic, generating a second signal with second characteristic, scaling the second signal at least in time and an amplitude to form a scaled signal and iteratively adding the scaled signal to the first signal to generate the reference signal. The iteratively adding comprises time indexing the first signal with plurality of time points, adding the scaled signal to first signal at each time point in the plurality of time points, computing a cost function to determine the cost of adding the scaled signal at each time point in the plurality of time points, selecting a set of time points that indicate reduction in the cost when the scaled signal is added and adjusting the amplitude of the scaled signal at each time point in the set of time points to reduce the cost.

Disclosed herein are embodiments that relate to phase coded linear frequency modulation for a radar system. Embodiments include transmitting at least two signal pulses. The transmitting includes transmitting a first pulse with a first phase modulation and a first chip rate, and transmitting a second pulse with a second phase modulation and a second chip rate. The second chip rate may be different than the first chip rate. Embodiments also include receiving a signal that includes at least two reflection signals associated with reflection of the at least two transmitted signal pulses. Embodiments further include processing the received signal to determine target information. The processing includes filtering the received signal to time-align the at least two reflection signals. The filtering includes applying a frequency-dependent time delay to one or more of the at least two reflection signals. Additionally, embodiments include removing phase code modulations from the time-aligned reflection signals.

Embodiments include methods for managing operation of a first radar system executed by a processor of a first user equipment (UE) of a first vehicle having the first radar system. In various embodiments, a processor of a first UE of the first vehicle may receive at the first UE from a base station, a wireless communication control message including radar transmission configuration information or radar reception interference information regarding the radar signals from a second radar system of a second vehicle having a second UE. Some embodiments may use the radar transmission configuration information or radar reception interference information received from the base station to manage operation of the first radar system.

Automotive radar methods and systems for enhancing resistance to interference using a built-in self-test (BIST) module. In one illustrative embodiment, an automotive radar transceiver includes: a signal generator that generates a transmit signal; a modulator that derives a modulated signal from the transmit signal using at least one of phase and amplitude modulation; at least one receiver that mixes the transmit signal with a receive signal to produce a down-converted signal, the receive signal including the modulated signal during a built-in self-test (BIST) mode of operation; and at least one transmitter that drives a radar antenna with a selectable one of the transmit signal and the modulated signal.

A radar system has different modes of operation. In a method for operating the radar system, at least one of one or more transmitters are configured to transmit modulated continuous-wave radio signals, while at least one of one or more receivers are configured to receive radio signals. The received radio signals include the transmitted radio signals transmitted by the one or more transmitters and reflected from objects in the environment. The method further includes selectively modifying an operational parameter of at least one of the transmitters or at least one of the receivers. The selected operational parameter is modified to meet changing operational requirements of the radar sensing system.

A method includes: receiving a ranging signal from the transmitter comprising a set of multiplexed sub-signals, each multiplexed sub-signal characterized by a frequency in a set of frequencies; calculating a time-based time-of-arrival estimate based on the series of time-domain samples of the ranging signal; calculating a time-based uncertainty of the time-based time-of-arrival; for each sub-signal pair in a subset of multiplexed sub-signals of the set of multiplexed sub-signals, extracting a phase difference of the sub-signal pair; calculating a phase-based time-of-arrival estimate based on the phase difference of each sub-signal pair in the subset of multiplexed sub-signals; calculating a phase-based uncertainty of the phase-based time-of-arrival estimate; and calculating a hybrid time-of-arrival estimate as a weighted combination of the time-based time-of-arrival estimate, the phase-based time-of-arrival estimate, based on the time-based uncertainty and the phase-based uncertainty.

A radar sensing system including transmit antennas and receive antennas, transmitters, receivers, and a controller. The system further includes a transmit antenna switch selectively coupling each of the transmitters to a respective transmit antenna, and a receive antenna switch selectively coupling at least one receiver of the receivers to respective receive antennas. A quantity of receivers is different from a quantity of the receive antennas. The controller is operable to select a quantity of receivers to be coupled to receive antennas to realize a desired quantity of virtual receivers. The controller is operable to select an antenna pattern as defined by the selected quantity of receivers coupled to receive antennas.

A radar sensing system for a vehicle includes a transmitter, a receiver, and an interference mitigation processor. The transmitter transmits radio signals. The receiver receives radio signals. The received radio signals include reflected radio signals that are each transmitted radio signals reflected from objects in the environment. The receiver also down-converts and digitizes the received radio signals to produce a baseband sampled stream. The interference mitigation processor produces a second received radio signal that includes reflected radio signals that are transmitted radio signals reflected from a first object. The interference mitigation processor uses the second received radio signal to remove selected samples from the baseband sampled stream that are attributed to radio signals reflected from the first object to produce a modified baseband sampled stream. The receiver uses the modified baseband sampled stream to detect a second object more distant than the first object.