Resource allocation method in multi-user cooperative relay system on basis of power minimization

The invention discloses a resource allocation method in a multi-user cooperative relay system on the basis of power minimization. According to the method, by means of equivalent channel gain, a two-hop link in the system is converted into a virtual direct-transmission link, then the joint optimization problem related to subcarrier allocation, relay selection and power allocation is decomposed into the following three sub-problems that firstly, the number of subcarriers occupied by users is determined by means of a power minimization rule according to average channel gain and the target rate of the users; secondly, on the principle that the channel condition is optimal, the target rate of the users is taken into consideration at the same time, subcarrier allocation is carried out in the mode that the subcarriers are used for selecting the users and a relay, so that the situation that one subcarrier is allocated to multiple users is avoided, and computation complexity is reduced; thirdly, by means of combination of a water-filling algorithm and channel environment, power allocation is carried out, and the fact that the total power of the system is minimum is guaranteed. Besides, in the processes of subcarrier allocation and relay selection, energy loaded on the subcarriers is minimum, and therefore energy consumption of the system is reduced.