A communication device includes one or more processors, configured to receive data representing each of at least a first waveform and a second waveform from a common control channel and data representing a third waveform from a data channel associated with the control channel; determine from the received data, channel state information for each of the first waveform and the second waveform; determine a Doppler shift between the channel state information for the first waveform and the channel state information for the second waveform; compare the determined Doppler shift to a predetermined Doppler shift threshold; and if the determined Doppler shift is less than the predetermined Doppler shift threshold, adjust the third received waveform by the determined Doppler shift and decode the adjusted third received waveform.

A communication method includes: determining, by a first device, a phase tracking reference signal (PTRS) pattern, where the PTRS pattern includes one or more PTRS chunks, and each PTRS chunk includes one or more PTRS samples; and mapping, by the first device, a PTRS to one or more symbols, and sending the one or more symbols to a second device.

The described technology is generally directed towards adaptively changing which transmission scheme a user equipment is to use based on a Doppler metric (e.g. Doppler frequency) as evaluated against a threshold Doppler value. A network instructs a user equipment to use a Rank-1 precoder cycling transmission scheme if the Doppler metric of user equipment is above a threshold value, or to use a closed loop MIMO transmission scheme if the user equipment has a Doppler metric below the threshold value. The network can instruct the user equipment via a suitable message, or by switching off TPMI and notifying the user equipment thereof.

This base station comprises: a control unit that allocates, on the basis of a doppler shift estimated using an uplink reference signal, a downlink reference signal common to a plurality of beams; and a transmission unit that transmits the common downlink reference signal via the plurality of beams. According to this base station communication method, the base station allocates, on the basis of a doppler shift estimated using an uplink reference signal, a downlink reference signal common to a plurality of beams, and transmits the common downlink reference signal via the plurality of beams.

A wireless communication device includes an estimation observation unit that observes a channel condition by estimating a tendency of a long delay wave and a channel fluctuation from a received signal in which a training signal is added to a data frame, a first equalizer that compensates for the received signal, a second equalizer that compensates for the received signal with a property of having a higher long delay wave tolerance and a lower channel fluctuation tolerance than the first equalizer, and a control unit that performs control which switches such that the first equalizer or the second equalizer performs compensation for the received signal, on the basis of the channel condition observed by the estimation observation unit.

To obtain delay spread estimations and/or Doppler spread estimations, data representing received data is input to at least one trained model, the trained model outputting spread estimations.

Transmission quality is improved in an environment in which direct waves dominate in a transmission method for transmitting a plurality of modulated signals from a plurality of antennas at the same time. All data symbols used in data transmission of a modulated signal are precoded by hopping between precoding matrices so that the precoding matrix used to precode each data symbol and the precoding matrices used to precode data symbols that are adjacent to the data symbol in the frequency domain and the time domain all differ. A modulated signal with such data symbols arranged therein is transmitted.

A communication method and system that combine the internet of things (IoT) technology with fifth generation (5G) communication systems supporting a higher data rate after fourth generation (4G) systems are provided. The present disclosure may be applied to intelligent services, such as smart homes, smart buildings, smart cities, smart or connected cars, healthcare, digital education, retail businesses, and security and safety related services on the basis of 5G communication technologies and IoT related technologies. A method of a terminal in a wireless communication system to improve DMRS channel estimation performance is provided. The method includes receiving first information configuring a physical resource block (PRB) bundling size indication based on second information, receiving the second information indicating the number of at least one PRB, if the PRB bundling size indication is configured, and estimating the channel state based on an assumption that the same precoding is applied to the at least one PRB based on the second information.

To provide demapping at a receiving side, a trained model for a demapper is used to output log-likelihood ratios of received signals representing data in a multi-user transmission. Inputs for the trained model for the demapper comprise a resource grid of equalized received signals.

A delay doppler domain transformation can be used to estimate characteristics of a channel between a base station and a user equipment or alternatively, between the user equipment and another user equipment. Thus, the velocity and the distance position of the user equipment can be calculated. For example, a signal received in the time-frequency domain, can be converted to the delay doppler domain by the base station. In response to the conversion, the base station can estimate the velocity of the user equipment. The velocity can be utilized by various applications. For example, the velocity can be utilized to alert the other user equipment to the location or an anticipated location of the user equipment.