A radio receiver for processing digital chirp spread-spectrum modulated signals that comprise a plurality of frequency chirps that are cyclically time-shifted replicas of a base chirp profile, said time-shifts being an encoded representation of a transmitted message. Includes a soft demapping unit that is adapted for working on fully populated as well as on partial modulation sets, and implements a timing error correction loop that acts back both in the time domain and in the frequency domain.

A communication device can be configured to detect radar signals within an operating channel. The communication device can include a mixer, filter, scanning and spreading circuit and a radar signal detector. The mixer can be configured to modulate a received communication signal based on an oscillating signal to generate a modulated signal. The filter can have a first bandwidth and be configured to filter the modulated signal. The scanning and spreading circuit can be configured to control the oscillating signal to scan an operating channel having a second bandwidth. The second bandwidth can be greater than the first bandwidth. The radar signal detector can be configured to detect a radar signal within the scanned operating channel.

An electronic device may include communications circuitry, sensing circuitry, and a set of antennas having first and second feeds for covering different polarizations. The communications circuitry may transmit signals with a first polarization using each of the antennas and may concurrently transmit signals with a second polarization using all but a selected one of the antennas. The sensing circuitry may concurrently transmit sensing signals with the first polarization using one of the antennas and may receive sensing signals with the second polarization using the selected antenna. The sensing signals may include chirp signals generated to include muted periods that correspond to a range of frequencies that overlap frequencies at which the wireless circuitry is subject to radio-frequency interference. This may allow for concurrent wireless communications and sensing operations without interference between the communications circuitry and the sensing circuitry.

A device comprises a digital ramp generator, an oscillator, a power amplifier, a low-noise amplifier (LNA), a mixer, and an intermediate frequency amplifier (IFA). The oscillator generates a chirp signal based on an output from the digital ramp generator. The power amplifier receives the chirp signal and outputs an amplified chirp signal to a transmitter antenna. The LNA receives a reflected chirp signal from a receiver antenna. The mixer receives output of the LNA and combines it with the chirp signal from the oscillator. The IFA receives the mixer output signal and includes a configurable high-pass filter, which has a first cutoff frequency during a first portion of the chirp signal and a second cutoff frequency during a second portion of the chirp signal. In some implementations, the first cutoff frequency is chosen based on a frequency of a blocker signal introduced by couplings between the transmitter and receiver antennas.

Certain aspects provide a method for radar detection by an apparatus. The method including transmitting a radar waveform in transmission time intervals (TTIs) to perform detection of a target object. The method further includes varying the radar waveform across TTIs based on one or more radar transmission parameters.

Methods for building, transmitting, and receiving frame structures in power line communications (PLC) are described. Various techniques described herein provide a preamble design using one or more symbols. One or more preamble symbols may be interspersed within a header portion of a PLC frame to facilitate estimation of a frame boundary and/or sampling frequency offset, for example, in the presence of impulsive noise.

A method is provided. In some examples, the method includes generating, by processing circuitry, a spread of chips representing an input bit. In addition, the method includes converting, by the processing circuitry, the spread of chips to a plurality of symbols comprising a pair of symbols. The method also includes mapping, by the processing circuitry, the pair of symbols to a single carrier signal and generating, by the processing circuitry, a radio-frequency (RF) signal based on the single carrier signal. The method further includes transmitting, by the processing circuitry via an antenna, the RF signal.

A novel and useful radar sensor incorporating detection, mitigation and avoidance of mutual interference from nearby automotive radars. The normally constant start frequency sequence for linear large bandwidth FMCW chirps is replaced by a sequence of lower bandwidth chirps with start frequencies spanning the wider bandwidth and randomly ordered in time to create a pseudo random chirp hopping sequence. The reflected wave signal received is reassembled using the known hop sequence. To mitigate interference, the signal received is used to estimate collisions with other radar signals. If detected, a constraint is applied to the randomization of the chirps. The chirp hopping sequence is altered so chirps do not interfere with the interfering radar's chirps. Offending chirps are re-randomized, dropped altogether or the starting frequency of another non-offending chirp is reused. Windowed blanking is used to zero the portion of the received chirp corrupted with the interfering radar's chirp signal.

Techniques are provided for asset location using backscatter communication. A methodology according to an embodiment includes receiving a signal, generated by a tag associated with an asset in response to a broadcast signal. The broadcast signal comprising a base code sequence, and the received signal comprising the broadcast signal modulated by a tag code sequence and shifted in frequency by a frequency offset. The methodology further includes translating the received signal by the frequency offset to generate a translated received signal, demodulating the translated received signal to remove the tag code sequence modulation to generate a demodulated received signal, cross-correlating the base code sequence with the demodulated received signal to generate a correlation signal, and determining a range to the asset based on a time delay associated with a peak of the correlation signal. The tag may be located based on the range and an estimated direction to the tag.

Described are power line communication (PLC) systems, devices and techniques which are reliable and suitable for use in control applications which can operate with relatively low data rates while complying with governing regulatory rules. Such systems, devices and techniques enable demand-side management of electrical loads in a building or facility or other environment.