Wireless communications systems and methods related to wireless communications in a system are provided. A user equipment (UE) may receive from a base station (BS), an uplink (UL) scheduling grant indicating subband precoding information and a resource allocation spanning a plurality of subbands. The UE may determine a plurality of subband precoders based on the subband precoding information. Each precoder of the plurality of subband precoders may be associated with a subband of the plurality of subbands. The UE may transmit to the BS, an UL communication signal in the resource allocation using the plurality of subband precoders.

A system for receiving multipath signals is disclosed. The system includes an equalizer that includes an input for a received data signal, wherein the received data comprises a first multipath component and a second multipath component. The equalizer further includes a channel impulse response estimator coupled to the input configured to determine one or more channel impulse response (CIR) estimates for the first multipath component and the second multipath component. The equalizer further includes a statistical estimation module coupled to the channel impulse response estimator configured to estimate a state of the first multipath component and the second multipath component based on the one or more channel impulse response estimates. The equalizer further includes a detector coupled to the statistical estimation module configured to detect data from the received data signal based on an estimated future state of the first multipath component and the second multipath component.

The embodiments provide cryptography that is performed in each of two communicating devices and is based on information known only to the devices. The information is determined in each of the devices at the time of communications. Each of the devices determines the information without communicating key information related to the encryption key with each other. Channel characteristic reciprocity between the two devices allows creation of identical keys in each device. Each of the devices sends a first setup signal to the other device, receives a second setup signal from the other device, where the second setup signal may be a looped back version of the first setup signal, samples the second setup generates sampling results, creates a key based on the sampling results, and utilizes the key to exchange one or more secure data signals with the other device.

The embodiments provide a cryptography key for two communicating devices that is based on information known only to the devices. The information may only be determined by the devices. Each device determines the information without communicating key information related to the encryption key with the other. Channel characteristic reciprocity between the devices allows creation of identical keys in each device. Each device sends a signal to the other device at the same power level based on the distance between the devices. The power level may be set to result in a target receive power level at the other device. Each device samples the received signal, generates sampling results, creates a key based on the sampling results and a threshold power level, and utilizes the key. The threshold power level may be based on the target receive power level, or a median power determined from the sampling results.

This disclosure describes systems, methods, and devices related to a trigger-based null data packet (NDP) for channel sounding system. A device may send a trigger frame to a group of station devices, the group of station devices including a first station device, the trigger frame indicating a high efficiency (HE) long training field (HE-LTF) mode and a guard interval duration. The device may identify a HE trigger-based (TB) null data packet (NDP) received from the first station device, the HE TB NDP including a first packet extension field, wherein the HE TB NDP is associated with the HE-LTF mode and the guard interval duration indicated in the trigger frame. The device may send a downlink NDP including a second packet extension field, a second HE-LTF mode, and a second guard interval duration. The device may determine channel state information based on HE TB NDP received from the first station device.

Provided is a wireless communication apparatus wherein channel estimation accuracy is improved while keeping the position of each bit in a frame, even when a modulation system having a large modulation multiple value is used for a data symbol. In the wireless communication apparatus, an encoding section encodes and outputs transmitting data to a bit converting section, and the bit converting section converts at least one bit of a plurality of bits constituting a data symbol to be used for channel estimation, among the encoded bit strings, into ‘1’ or ‘0’ and outputs it to a modulating section. The modulating section modulates the bit string inputted from the bit converting section by using a single modulation mapper and a plurality of data symbols are generated.

A detection system includes: a signal output unit configured to output, to a measurement target, a measurement signal that exhibits a predetermined temporal change; a signal measurement unit configured to measure a response signal, to the measurement signal, from the measurement target; a calculation unit configured to calculate an impulse response of the measurement target, based on a measurement result of the response signal measured by the signal measurement unit; and a detection unit configured to detect abnormality regarding the measurement target, based on the impulse response calculated by the calculation unit.

An electronic device is provided. The electronic device includes a first communication circuit, a second communication circuit, and at least one processor. The first communication circuit is configured to receive, in a first band, a first reflective signal reflected by an object, and obtain, based on the received first reflective signal, a first channel impulse response corresponding to the first reflective signal. The second communication circuit is configured to receive, in a second band, a second reflective signal reflected by the object, obtain, based on the received second reflective signal, a second channel impulse response corresponding to the second reflective signal, and obtain a third channel impulse response based on a first calculation using the second channel impulse response, a first central frequency of the first band and a second central frequency of the second band.

Methods, systems, and devices for wireless communications are described. A transmitting device (e.g., a user equipment (UE) or base station) may reduce a peak to average power ratio (PAPR) by clipping signals transmitted to a receiving device according to a clipping level. The receiving device may receive, from the transmitting device, an indication of the clipping level associated with a reference signal. The receiving device may receive the reference signal and identify distortions based on the clipping level. The receiving device may iteratively reconstruct peaks of the clipped reference signal until the receiving device is able to obtain accurate pilot symbols for use in channel estimation. The techniques described herein may enable receiving devices to improve efficiency and reliability of communications by improving channel estimation, which may increase the probability of successfully decoding transmitted information.

To facilitate positioning a user device, the user device is configured to measure, per an antenna array, reference signals received from transmission-reception points and to check, whether a downlink reference signal from a transmission-reception point is received in a serving antenna array and in one or more non-serving antenna arrays with a first delay. A non-serving antenna array receiving the signal with the first delay is an alternative antenna array to the serving antenna array. When the serving antenna array is under a maximum permissible exposure event, the user device is configured to select, which one of one or more alternative antenna arrays and the serving antenna panel is to be used for transmitting at least a positioning signal to the transmission-reception point.