Device-to-device (d2d) power control method, user equipment, base station, and communication system

A device-to-device (D2D) power control method, comprising:

• receiving, by a second user equipment UE, data sent by a first UE based on a transmit power of the first UE, and obtaining an adjustment reference value;
• and
• sending, by the second UE, detection control information to a base station according to the adjustment reference value, so that the base station sends power adjustment information to the first UE according to the detection control information, and the first UE adjusts the transmit power of the first UE according to the power adjustment information,
• wherein the transmit power of the first UE is obtained by the first UE according to path loss information sent by the base station or a reference signal sent by the second UE.

A device-to-device (D2D) power control method, comprising:

• sending, by a base station, path loss information to a first user equipment UE, or sending instruction information of a reference signal to the first UE and a second UE;
• receiving, by the base station, detection control information sent by the second UE according to an adjustment reference value;
• and
• sending, by the base station, power adjustment information to the first UE according to the detection control information, wherein the power adjustment information is used by the first UE to adjust a transmit power of the first UE,
• wherein the adjustment reference value is obtained by the second UE according to data sent by the first UE based on the transmit power of the first UE;
• and
• the instruction information is used to instruct the first UE to receive the reference signal sent by the second UE, or instruct the second UE to send the reference signal to the first UE.

A user equipment (UE), comprising:

• a processor, configured to receive path loss information sent by a base station or a reference signal sent by a second user equipment UE, and obtain a transmit power of the UE according to the path loss information or the reference signal;
• and
• a transmitter, configured to send data to the second UE based on the transmit power of the UE, so that the second UE obtains an adjustment reference value according to the data and sends detection control information to the base station according to the adjustment reference value,
• wherein the processor is further configured to receive power adjustment information sent by the base station according to the detection control information, and adjust the transmit power of the UE according to the power adjustment information.

A user equipment (UE), comprising:

• a processor, configured to receive data sent by a first UE based on a transmit power of the first UE, and obtain an adjustment reference value;
• and
• a transmitter, configured to send detection control information to a base station according to the adjustment reference value, wherein the base station sends power adjustment information to the first UE according to the detection control information, and the first UE adjusts the transmit power of the first UE according to the power adjustment information,
• wherein the transmit power of the first UE is obtained by the first UE according to path loss information sent by the base station or a reference signal sent by the UE.

A base station, comprising:

• a transmitter, configured to send path loss information to a first user equipment UE, or send instruction information of a reference signal to the first UE and a second UE;
• a receiver, configured to receive detection control information sent by the second UE according to an adjustment reference value, wherein the adjustment reference value is obtained by the second UE according to data sent by the first UE based on a transmit power of the first UE;
• and
• a processor, configured to send power adjustment information to the first UE according to the detection control information, wherein the power adjustment information is used by the first UE to adjust the transmit power of the first UE,
• wherein the instruction information is used to instruct the first UE to receive a reference signal sent by the second UE, or instruct the second UE to send the reference signal to the first UE.