Method for harq and link adaptaion of device to device link in direct communication between user equipments and relaying by user equipment

PURPOSE: A method for processing a HARQ and adaptive transmission in a device to a device link for end-to-end direct connection communication and terminal relaying is provided to improve capacity and performance in D2D communications since the method for processing the HARQ and adaptive transmission is adopted for the D2D communications. CONSTITUTION: An initial transmission mode and transmission power for a D2D link are received from a base station. Data is transmitted through the D2D link. A terminal determines the transmission mode and the transmission power of a following subframe by receiving a transmission mode control value and a transmission power control value from a counterpart terminal in the D2D link. The data is transmitted to the counterpart terminal by using the determined transmission mode and the transmission power.