Methods and apparatus of channel estimation using time-domain parameter extraction are disclosed. The wireless channel can be modeled by a multipath model with a limited number of parameters in the continuous time domain. Extracting the time-domain parameters and then reconstructing the channel yields channel estimates that have better accuracy. Time-domain parameter extraction also has lower computational complexity than existing methods.

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 base station defines a short TTI (transmission time interval) equal to the length of one subslot as the minimum unit of a time resource for data transmission in a subframe including a plurality of subslots, determines the RS type the terminal will use for transmission, among a plurality of RS types, based on the positions of RSs (reference signals) within the short TTI, and sends information on the RS type the terminal will use for transmission to the terminal.

A method for channel estimation, performed by a wireless transmit/receive unit (WTRU), includes: receiving a plurality of input signals, generating a plurality of sensing matrices for the input signals, generating an augmented sensing matrix and an augmented observation vector according to the sensing matrices and the input signals, estimating a plurality of channel delay parameters according to the augmented sensing matrix and the augmented observation vector, and estimating channel information according to the channel delay parameters.

Techniques and architectures for multi-stage cancellation of self-interference (SI) and joint cancellation of mutual-interference (MI) and residual SI in signals received by devices of a full-duplex multi-cell network are disclosed. In various examples, channel estimations and interference cancellation operations are performed utilizing multiple orthogonal training signals transmitted by network devices during a common over-the-air training period. Training signals derived from the orthogonal training signals during transmission are utilized to generate SI estimation information and perform at least a first SI cancellation operation on a received signal that includes at least first and second orthogonal training signals. The received signal and orthogonal training signals are then used to estimate a MI channel impulse response and a (residual) SI channel impulse response for use in joint MI/SI cancellation operations on further received signals. Details regarding the design of the orthogonal training signals and a unique system-level delay calibration procedure are also provided.

At least one embodiment relates to power delay profile (PDP) estimation e.g. in 5G systems for channel estimation and for demodulation. The power delay profile is estimated directly in the frequency domain using LMMSE properties based on the knowledge of channel statistics. An example embodiment applies an approximation by estimating the second order statistics of the channel autocorrelation function in time domain represented by the variance of the derivative of raw channel estimates in frequency domain.

The present disclosure is directed to time stamp detection using a cable modem and to a control apparatus, control device and control method for detecting timestamps in various signals such as orthogonal frequency division multiplexing (OFDM) signals. The control apparatus comprising processing circuitry being configured to obtain information a channel frequency response of the multi-path channel, the channel frequency response being based on a signal comprising a sequence of symbols. The processing circuitry is configured to transform the channel frequency response into a channel impulse response. The processing circuitry is configured to identify a peak in the channel impulse response. The processing circuitry is configured to determine a timestamp offset time between the peak in the channel impulse response and a trigger time indicative of a beginning of a symbol in the signal. The processing circuitry is configured to synchronize the device clock based on the timestamp offset time.

Techniques are provided for utilizing a hybrid of ultra-wideband (UWB) and narrowband (NB) signaling to provide more efficient operating range and operating efficiency. In one example, a first device may transmit a first packet via an NB signal to a second device, whereby the first packet comprises information indicating to the second device a time period for reception of a second (UWB) packet. In this example, the second packet may comprise a first partition and a second partition, whereby the first partition comprises a first plurality of fragments and the second partition comprising a second plurality of fragments. The respective fragments of each plurality of fragments may be transmitted via a UWB signal. The first device may then transmit the first plurality of fragments, and then subsequently transmit the second plurality of fragments to the second device, the first and second pluralities respectively being associated with different fragment types.

Systems and methods for coverage enhanced reciprocity-based precoding schemes are provided. In some embodiments, a method performed by a base station for determining precoding information includes: determining channel estimates for at least a channel between the wireless device and another device; determining a plurality of precoding hypotheses based on the channel estimates; determining a figure of merit for each of the plurality of precoding hypotheses; and determining the precoding information based on the figure of merit for each of the plurality of precoding hypotheses. In some embodiments, this precoding method enables the use of reciprocity-based precoding down to a lower Signal to Noise Ratio, SNR, than what existing state of the art reciprocity-based precoding can offer.

The present invention provides an electronic device including a first antenna, a second antenna and a wireless communication chip. The wireless communication chip is configured to control the first antenna to broadcast a packet, control the second antenna to receive the packet broadcasted from the first antenna, and determine channel state information according to the packet received by the second antenna.