Method for determining user equipment downlink MCS

The invention discloses a method for determining a user equipment downlink MCS. The method includes the steps that the initial MCS grades of all user equipment are set through a base station; the frequency deviation values of uplink data of the user equipment are measured through the base station, and users similar in absolute frequency value are classified into a big group; the user equipment in all the big groups is further classified into different small groups according to service types; for all the user equipment in the same small group, the ratio k of ACK feedbacks of all downlink services, which are received by F sub-frames, to all feedbacks is calculated; according to the relation between k and a preset threshold value, the MCS grades are adjusted. Compared with the prior art, signaling overheads can be reduced, and meanwhile the MCS grades of the user equipment can be adjusted in time.