The embodiments provide a cryptography key for two communicating devices that is based on information known only to the devices. Each of the communicating devices determines the information without communicating key information related to the encryption key with the other. Each device receives a setup signal sent by the other device. Each device samples the received signal, generates sampling results, creates a plurality of keys based on the sampling results, selects a key of the plurality of keys based on criteria, and utilizes the selected key. The sets of plurality of keys may be created by creating each of the keys based on a different power threshold applied to the sampling results. The sets of plurality of keys may also be created by inputting the sampling results into each of a plurality of decoders to generate a key at each decoder that comprises a key of the plurality of keys.

Embodiments of the present disclosure include an OFDM receiver circuit, which includes an FFT circuit configured to calculate an FFT of a plurality of sample values received by the receiver circuit, and a smoothing circuit configured to identify equalizer coefficients for the sample values by truncating portions of an impulse response of the FFT.

Fiber, cable, and wireless data channels are typically impaired by reflectors and other imperfections, producing a channel state with echoes and frequency shifts in data waveforms. Here, methods of using OTFS pilot symbol waveform bursts to automatically produce a detailed 2D model of the channel state are presented. This 2D channel state can then be used to optimize data transmission. For wireless data channels, an even more detailed 2D model of channel state can be produced by using polarization and multiple antennas in the process. Once 2D channel states are known, the system turns imperfect data channels from a liability to an advantage by using channel imperfections to boost data transmission rates. The methods can be used to improve legacy data transmission modes in multiple types of media, and are particularly useful for producing new types of robust and high capacity wireless communications using non-legacy OTFS data transmission methods.

A method for estimating performance of a serial communication channel using processing circuits. The channel is configured to transmit a binary input stream from a transmitting end to an output stream at a receiving end. The method includes modeling by the processing circuits the channel at the receiving end as a first finite impulse response (FIR) system. The modeling includes estimating a cursor pulse response of the first FIR system by analyzing the output stream received at the receiving end, and estimating one or more pre-cursor or post-cursor pulse responses of the first FIR system from the received output stream using the estimated cursor pulse response. The method further includes determining by the processing circuits a performance metric by using the estimated one or more pre-cursor or post-cursor pulse responses.

A multilevel power line communication quantization method for physical layer security is provided. The multilevel quantization method includes generating an estimated channel impulse response of at least one link between a first node and a second node; performing a quantization of the estimated channel impulse response; generating a virtual channel impulse response; performing a quantization of the virtual channel impulse response for generating a first key and a second key, wherein the first key has a corresponding first position vector and the second key has a corresponding second position vector; and confirming that the first key and the second key are equal.

There is provided a method performed by a user equipment (UE). The method comprises: receiving a reference signal over multiple time instances; determining time domain properties of a channel, based on the received reference signal; and sending a report to a network node, the report comprising information about the determined time domain properties of the channel. A UE for implementing this method is also provided.

A method for estimating the distance of an element with respect to a vehicle on the basis of a detection module. The method includes, implemented by the detection module, determining the standard deviation of the phase of signals reflected from the element for each distance index of a series of distance indices, determining, in the order of the series, the first index for which the standard deviation is below a predetermined threshold for at least a predetermined length of time, and estimating the distance of the element with respect to the detection module on the basis of the determined index, the estimated distance corresponding to the predetermined distance associated with the determined index.

To increase positioning accuracy, channel characteristics are determined taking into account receive filter response and transmit filter response. For example, upon receiving assistance data for positioning an apparatus, a transmit sequence is generated using the assistance data; and a combination of the transmit sequence is generated by combining the transmit sequence. Further, a receive filter response is determined, a transmit filter response is obtained, and a combined filter response is generated using the receive filter response and the transmit filter response. Reference signals received over a channel are measured by sampling them into a plurality of time-domain samples, and the channel is estimated from the plurality of time-domain samples using the combined filter response and the combination of the transmit sequence. Then, per channel characteristics, a value of the channel characteristics based on the channel estimated is determined.

Embodiments of wireless communications systems, ultra-wide band (UWB) systems, and methods for wireless communications are described. In an embodiment, a wireless communications system includes a processor configured to obtain an angle of arrival (AoA) estimate from wireless signals; perform a Channel Impulse Response (CIR) analysis, and determine a confidence level for the AoA estimate based on the CIR analysis.

This disclosure provides methods, components, devices and systems for adjacent channel interference (ACI) mitigation techniques for ultra-wideband (UWB) systems. Some aspects more specifically relate to ACI mitigation for UWB systems. In some implementations, a wireless communication device may receive control information that identifies a preamble for communications to the wireless communication device in a UWB system. The wireless communication device may receive, via a signal in the UWB system, a data packet that includes the preamble. The wireless communication device may estimate a channel impulse response (CIR) of the signal and determine an interference metric that is based on the estimated CIR. The wireless communication device may process the data packet based on the interference metric.