In order to efficiently compensate for effects of the Doppler shift, a receiving device includes a Doppler estimator that estimates a Doppler-shift frequency fdc of a received signal. A multiplier and an LPF detect the received signal based on a carrier frequency fc of the received signal and the Doppler-shift frequency fdc estimated by the Doppler estimator 11. A timing corrector corrects a timing T for extracting symbols of the received signal after detection by the LPF so as to track the Doppler shift. A symbol extractor extracts received symbols from the received signal after detection by the LPF at a timing corrected by the timing corrector. An adaptive equalizer estimates and determines symbols from the received symbols extracted by the symbol extractor.

Aspects of the disclosure relate to a method of, and apparatus for, wireless communication by a user equipment (UE). The method includes receiving a set of reference signals and transmitting, based at least in part on the set of reference signals: a set of Doppler frequency values and a set of weight values that correspond to the set of Doppler frequency values. In another example, a method of, and apparatus for, wireless communication by a base station (BS) is disclosed. The method includes transmitting, to the UE, a signal that has been precoded based at least in part on the set of Doppler frequency values, and the corresponding set of weight values. Other aspects, embodiments, and features are also claimed and described.

Systems, methods, and terminals for synchronization of signal timing between a first terminal and a second terminal are provided herein. The system and method includes transmitting a signal from a first terminal to a second terminal, the signal comprising a phase and a plurality of frames, receiving the signal at the second terminal, periodically inverting the phase of the signal at the frame interval to produce an inversion coded signal comprising at least one phase inversion point, transmitting the inversion coded signal from the second terminal to the first terminal, receiving the inversion coded signal at the first terminal, and determining transmission timing of the signal from the first terminal to the second terminal by measuring a timing discrepancy between the at least one phase inversion point and a start time of a next frame.

Systems, methods, and terminals for synchronization of signal timing between a first terminal and a second terminal are provided herein. The system and method includes transmitting a signal from a first terminal to a second terminal, the signal comprising a phase and a plurality of frames, receiving the signal at the second terminal, periodically inverting the phase of the signal at the frame interval to produce an inversion coded signal comprising at least one phase inversion point, transmitting the inversion coded signal from the second terminal to the first terminal, receiving the inversion coded signal at the first terminal, and determining transmission timing of the signal from the first terminal to the second terminal by measuring a timing discrepancy between the at least one phase inversion point and a start time of a next frame.

Diversity receiver front end system with amplifier phase compensation. A receiving system can include a first amplifier disposed along a first path, corresponding to a first frequency band, between an input of the receiving system and an output of the receiving system. The receiving system can include a second amplifier disposed along a second path, corresponding to a second frequency band, between the input of the receiving system and the output of the receiving system. The receiving system can include a first phase-shift component disposed along the first path and configured to phase-shift the second frequency band of a signal passing through the first phase-shift component based on a phase-shift caused by the first amplifier at the second frequency band.

Diversity receiver front end system with amplifier phase compensation. A receiving system can include a first amplifier disposed along a first path, corresponding to a first frequency band, between an input of the receiving system and an output of the receiving system. The receiving system can include a second amplifier disposed along a second path, corresponding to a second frequency band, between the input of the receiving system and the output of the receiving system. The receiving system can include a first phase-shift component disposed along the first path and configured to phase-shift the second frequency band of a signal passing through the first phase-shift component based on a phase-shift caused by the first amplifier at the second frequency band.

A data transmission method is provided. The method includes obtaining configuration information, wherein the configuration information indicates transmission resources of a random access preamble and payload data corresponding to the random access preamble, transmitting the random access preamble and the payload data at the transmission resources, modulating the payload data using a modulation scheme supporting asynchronous transmission, and receiving feedback information, wherein the feedback information comprises an indication which indicates whether the payload data is successfully received. Various examples of the present disclosure also describe a method for receiving data with space multiplexing which is applied to a base station side, and further describe a terminal and a base station. Employing the examples of the present disclosure, transmission efficiency of long duty cycle and sporadic small data packets of a large number of devices in the Internet of Things in future communication systems can be improved.

The present invention relates to a method and device for measuring channel quality by a base station having a two-dimensional active antenna system including multiple antennas. Particularly, the method comprises: receiving channel state information (CSI) generated on the basis of a first reference signal relating to a part of multiple antennas, from a terminal; selecting a precoding and a rank based on a precoding matrix indicator (PMI) and a rank indicator (RI) of the received CSI; generating a port by applying the selected precoding and the selected rank; through the generated port, transmitting, to the terminal, a physical downlink shared channel (PDSCH) and a demodulation-reference signal (DM-RS) configured for the terminal; and receiving, from the terminal, a channel quality indication (CQI) feedback for reducing a mismatch for the CQI of the CSI, wherein the CQI feedback may be generated based on the DM-RS.

A baseband receiving unit receives a signal transmitted from a wireless communication terminal device and including a plurality of symbols arranged in a time direction. A scheduling unit estimates the frequency offset based on a first signal that is for measuring quality and that is mapped to a first symbol placed at a predetermined position in the transmitted signals received with the baseband receiving unit, and a second signal that is for demodulation and that is mapped to a second symbol placed at a position different from the first symbol in the transmitted signal.

An n input, radio frequency (RF) signal matrix is formed of a plurality of two-to-one RF signal routing units each including first, second, and third switching units selectively connecting either a first input to an output via a bypass conductive path while electrically isolating first and second signal combining conductive paths from the output or first and second inputs to the output via first and second signal combining conductive paths while electrically isolating the bypass conductive path from the output. The RF signal routing units are connected in at least two levels with outputs from a first level connected to inputs for a second level to form the n inputs for the RF signal matrix. Any number of the n inputs may be employed without unused inputs loading the output.