A base station (eNB) determines device-to-device (D2D) transmission parameters for signal transmission over a D2D communication link between a first user equipment (UE) device and a second UE device. The eNB instructs the first UE device to transmit a reference signal that is received by the second UE device. The second UE device reports D2D channel characteristic information indicative of the received reference signal. Based on the D2D channel characteristic information, the base station determines the D2D transmission parameters and provides the parameters to the first UE device.

A base station (eNB) determines device-to-device (D2D) transmission parameters for signal transmission over a D2D communication link between a first user equipment (UE) device and a second UE device. The eNB instructs the first UE device to transmit a reference signal that is received by the second UE device. The second UE device reports D2D channel characteristic information indicative of the received reference signal. Based on the D2D channel characteristic information, the base station determines the D2D transmission parameters and provides the parameters to the first UE device.

In a communication system having a plurality of user equipment (UE) devices that are operating in a contention based mode for device-to-device (D2D) communication, each UE device transmits a preferred transmission indicator when a condition for preferred transmission is met at the UE device. If a UE device receives a preferred transmission indicator, the UE device delays transmission of a D2D scheduling assignment (SA) to contend for communication resources for D2D communication. The length of the delay can be based on a number of preferred transmission indicators that are received. The preferred transmission indicator is based on a buffer size in one example.

In a communication system having a plurality of user equipment (UE) devices that are operating in a contention based mode for device-to-device (D2D) communication, each UE device transmits a preferred transmission indicator when a condition for preferred transmission is met at the UE device. If a UE device receives a preferred transmission indicator, the UE device delays transmission of a D2D scheduling assignment (SA) to contend for communication resources for D2D communication. The length of the delay can be based on a number of preferred transmission indicators that are received. The preferred transmission indicator is based on a buffer size in one example.

A beam failure recovery method and device are provided. The method includes: after a beam failure recovery event is triggered, user equipment (UE) monitoring a physical downlink control channel (PDCCH) scrambled with a cell radio network temporary identifier (C-RNTI) in a first control channel resource set (CORESET) for beam failure recovery, and monitoring a PDCCH scrambled with a C-RNTI in a second CORESET.

Methods and apparatuses are disclosed for performing fast beam switching in a high-frequency wireless communication environment. Higher frequencies reduce transmission wavelength, which allows for an increased number of antennas and an increased number of beams. Therefore, beams become narrower and are more prone to failure. The UE must be capable of quickly identifying the beam failure and switching to a new beam. Therefore, the UE is capable of receiving multiple beams from the base station and configures both for testing and immediate use. In some cases, the UE can receive multiple beams for testing and assumes a default beam while feeding back to the base station a preferred beam. To support the larger number of available beams, MAC-CE and DCI are modified to identify this increased number of states. Alternatively, two MAC-CEs are sent, each containing a different group of states, and the DCI identifies both the group and the selected state.

Methods and apparatuses are disclosed for performing fast beam switching in a high-frequency wireless communication environment. Higher frequencies reduce transmission wavelength, which allows for an increased number of antennas and an increased number of beams. Therefore, beams become narrower and are more prone to failure. The UE must be capable of quickly identifying the beam failure and switching to a new beam. Therefore, the UE is capable of receiving multiple beams from the base station and configures both for testing and immediate use. In some cases, the UE can receive multiple beams for testing and assumes a default beam while feeding back to the base station a preferred beam. To support the larger number of available beams, MAC-CE and DCI are modified to identify this increased number of states. Alternatively, two MAC-CEs are sent, each containing a different group of states, and the DCI identifies both the group and the selected state.

In a wireless communication system in which propagation delays between a plurality of terminal station devices and a base station device, which use time division multiplexing in a duplex operation system, are different from each other, at least one of the base station device or the terminal station devices includes a delay calculating unit that calculates the propagation delay for each of the terminal station devices, and the base station device includes a control unit that changes a frame configuration such that a standby time required for switching between an uplink frame and a downlink frame is shortened in accordance with the propagation delay for each of the terminal station devices. In accordance with this, a surplus standby time can be shortened, and a transmission capacity can be improved.

In a wireless communication system in which propagation delays between a plurality of terminal station devices and a base station device, which use time division multiplexing in a duplex operation system, are different from each other, at least one of the base station device or the terminal station devices includes a delay calculating unit that calculates the propagation delay for each of the terminal station devices, and the base station device includes a control unit that changes a frame configuration such that a standby time required for switching between an uplink frame and a downlink frame is shortened in accordance with the propagation delay for each of the terminal station devices. In accordance with this, a surplus standby time can be shortened, and a transmission capacity can be improved.

This application provides a modulation and coding scheme (MCS) selection method. In the method, a first communication device determines a predicted block error rate that corresponds to each MCS of a plurality of MCSs at a transmission time interval (TTI) 1 by using a neural network model, where a prediction parameter that corresponds to each MCS includes a channel parameter and the MCS. The first communication device selects, from the plurality of MCSs based on the plurality of MCSs and the predicted block error rate that corresponds to each MCS, a target MCS that corresponds to the TTI 1, and sends data to a second communication device at the TTI 1 based on the target MCS. The method disclosed herein helps improve channel transmission performance.