Embodiments of the present invention relate to the communications field and disclose a data transmission device, method, and system, so as to better improve an average downlink throughput of UE. A specific solution is: A determining unit determines a downlink frequency shift according to a received uplink signal sent by a terminal device, and determines a second transmit frequency according to the downlink frequency shift and a first transmit frequency; and a sending unit sends a downlink signal to the terminal device according to the second transmit frequency determined by the determining unit, so that the terminal device receives the downlink signal according to a receive frequency corresponding to the first transmit frequency, where the downlink signal includes at least one of a DMRS or downlink data. The present invention is applied in a data transmission process.

A method for distortion compensation in a transmission link comprising obtaining information of an amplitude distribution of a signal prior to being transmitted by a transmitter, receiving the transmitted signal at a receiver and determining a received signal amplitude distribution, comparing the received signal amplitude distribution to the amplitude distribution of the signal prior to transmission and using results of the comparison to estimate the AM/AM non-linearity in the transmitter.

A wireless device or network node determines an evaluation period that is common to at least a portion of reference signal resources in a set of reference signal resources that are transmitted by the network node, with at least one of the reference signal resources in the set being of a different type or configuration than another of the reference signal resources in the set.

Various arrangements for compensating for Doppler shift on a non-terrestrial orthogonal frequency division multiplex (OFDM) network are presented. An absolute location of the UE instance may be determined. A relative velocity of the UE instance with respect to a satellite of the non-terrestrial OFDM network may be determined. A frequency delta due to Doppler shift may be determined. A transmission frequency at which an uplink OFDM symbol is to be transmitted to the satellite of the non-terrestrial OFDM network may be determined using the frequency delta.

A wireless base station or user equipment (BS or UE) includes a receiver configured to receive a frequency division multiplexed (FDM) symbol transmitted by another wireless BS or UE, and a processor. The processor is configured to process the received FDM symbol to obtain its equalized FDM data subcarriers, generate a CPE estimate using the equalized FDM data subcarriers, and send to the other wireless BS or UE control messages that indicate a CPE compensation performance level using the CPE estimate. The other wireless BS or UE is enabled by the control messages to adapt a density in time and/or frequency of embedded pilot symbols within FDM symbols subsequently transmitted to the wireless BS or UE.

A method for correcting an error in the generation of a frequency by a frequency synthesizer of a terminal of a terrestrial wireless communication system. A query message is transmitted by the terminal. Error in the generation of the frequency of the query message is estimated by an access network as a function of a theoretical transmission frequency of the query message by the terminal and an actual frequency of reception of the query message by the access network. A response message comprising an item of correction information is transmitted by the access network. A frequency of reception by the terminal of a broadcast signal transmitted by the access network is generated by the frequency synthesizer of the terminal and as a function of the item of correction information received by the access network.

Aspects of the present disclosure provide techniques for phase tracking in wireless communications using frames with some portions that use relatively long symbol durations.

In a time deviation determining method, a terminal determines an uplink timing advance between the terminal and a base station; determines a one-way transmission delay based on the uplink timing advance; and determines a clock time deviation between the terminal and the base station based on the one-way transmission delay, a time difference between a base-station clock time of a system frame in two system frames and a terminal clock time of a following system frame in the two system frames, and a time difference between the two system frames. In the solution provided in this application, the clock deviation between the terminal and the base station can be determined more flexibly and accurately. In addition, signaling interaction between the terminal and the base station is reduced, and network resources are saved.

In an embodiment, a distributed antenna system, comprises a master unit communicatively coupled to a base station; and a remote unit communicatively coupled to the master unit via a communication medium and located remotely from the master unit, wherein the remote unit includes an internal clock; wherein the master unit is configured to: send a message to the remote unit including a list of service frequencies and applied standards for the base station; send a downlink signal generated based on a base station signal to the remote unit; wherein the remote unit is configured to: decode the downlink signal based on the list of service frequencies and applied standards for the base station; extract a base station clock signal from the downlink signal; and synchronize the internal clock to the base station clock using the extracted base station clock signal.

According to one embodiment, a synchronization circuit includes a received-signal detecting unit which detects a received signal including a first and a second reference signal, a timing-synchronization adjusting unit including a storage module storing information of the first reference signal and a correlation operating module carrying out correlation operation of the first reference signal included in the received signal and the information of the first reference signal output from the storage module, the timing-synchronization adjusting unit which carries out timing synchronization so that a result of the correlation operation carried out by the correlation operating module becomes a predetermined value, and a phase-synchronization adjusting unit which carries out phase synchronization of a subcarrier by adjusting a component varied depending on a phase of a subcarrier frequency by using a phase modulation signal included in the second reference signal, wherein the received signal is a filtered multicarrier signal.