Generated chirp pulses are modified so that they have an increased time bandwidth product to compensate for noise and/or attenuation in a communication channel In certain circumstances, the modification alone may be inefficient so a counterbalancing modification may be applied at the receiver.

Techniques and apparatuses are described that facilitate ambient computing using a radar system. Compared to other smart devices that rely on a physical user interface, a smart device with a radar system can support ambient computing by providing an eye-free interaction and less cognitively demanding gesture-based user interface. The radar system can be designed to address a variety of challenges associated with ambient computing, including power consumption, environmental variations, background noise, size, and user privacy. The radar system uses an ambient-computing machine-learned module to quickly recognize gestures performed by a user up to at least two meters away. The ambient-computing machine-learned module is trained to filter background noise and have a sufficiently low false positive rate to enhance the user experience.

A radio frequency communication system includes a radio frequency transmitter having a chirp generator operable to transmit a first chirp signal, and transmit a second chirp signal that is circular shifted relative to the first chirp signal. A receiver receives the first chirp signal and the second chirp signal, such that the proportion of phase offset between the first and second chirp signals is proportional to the frequency offset of the received signals. The first and second chirp signals are despread, and the phase difference between the first and second chirp signals is used to determine a frequency offset of the received first and second chirp signals that is proportional to the phase difference between the first and second chirp signals.

Methods and apparatus for transmitting power and data along a metal pipe using wideband acoustic waves. Arrangements use shear-horizontal waves, transmitting narrowband signals for power applications and wideband signals for communications having a bandwidth greater than the coherence bandwidth of the acoustic-electric channel. Chirp wave signals, direct sequence spread signals, and on-off keying are used. Acoustic-electric channels include wedges fixed to a pipe or other substrate, transducers fixed to the wedges, and electronics linked to each transducer for sending and receiving power and signals. Matching networks, rectification circuits, and non-coherent signal reception methods may be used.

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.

Methods, systems and devices for wireless communication are described. One example method includes mapping information bits to transmission resources in a two-dimensional delay-Doppler grid In this example, the two-dimensional delay-Doppler grid includes N Doppler elements along a Doppler dimension and M delay elements along a delay dimension, and N and M are positive integers. The example method continues with converting a result of the mapping to a signal waveform, and generating an orthogonal time frequency space (OTFS) waveform by spreading the signal waveform using a spreading scheme. In some examples, the signal waveform includes an ultra-wide band (UWB) waveform.

In one aspect, an apparatus comprises: a radio frequency (RF) front end circuit to receive and process an RF signal comprising a packet, the RF front end circuit to output a digital signal comprising the packet; and a baseband circuit coupled to the RF front end circuit. The baseband circuit may comprise: a demodulator to receive the digital signal comprising a plurality of extended and modulated symbols and to: perform a plurality of operations on at least some of a first block of the plurality of extended and modulated symbols according to a reverse recipe of operations to obtain a processed first block of the plurality of extended and modulated symbols; aggregate the processed first block of the plurality of extended and modulated symbols into an aggregated symbol; and demodulate the aggregated symbol to obtain at least one soft value.

In one embodiment, an apparatus includes a circuit to: modulate a symbol with a sequence; extend the modulated symbol to obtain a plurality of modulated symbols; and perform, on the plurality of modulated symbols, a plurality of operations according to a Recipe of operations, to obtain extended and modulated symbols. The apparatus may further include a radio frequency (RF) front end circuit coupled to the circuit to process and transmit the extended and modulated symbols.

Techniques and apparatuses are described that train machine-learned modules to perform radar-based gesture detection in an ambient compute environment. Compared to other smart devices that rely on a physical user interface, a smart device (104) with a radar system (102) can support ambient computing by providing an eye-free interaction and less cognitively demanding gesture-based user interface. The radar system (102) can be designed to address a variety of challenges associated with ambient computing, including power consumption, environmental variations, background noise, size, and user privacy. The radar system (102) uses an ambient-computing machine-learned module (222) to quickly recognize gestures performed by a user up to at least two meters away. The ambient-computing machine-learned module (222) is trained, at least in part, using a two-phase evaluation process, which includes a segmented classification task and an unsegmented recognition task.

Techniques are provided for generating secure radio frequency (RF) sensing waveforms to reduce the risk of a man-in-the-middle (MITM) attack for positioning, sensing and communications. An example method for transmitting a secure radio frequency sensing waveform includes transmitting a first set of parameters including timing information or frequency information associated with a radio frequency sensing waveform, transmitting the radio frequency sensing waveform, and transmitting a second set of parameters including scrambling information associated with the radio frequency sensing waveform.