Method and device for estimating downlink channel quality

A method, device and system for estimating downlink channel quality are provided. Directly estimating downlink channel quality by network side can greatly reduce the feedback overhead of user devices. The embodiment of the method includes that the network device receives the downlink channel quality indicator or the interference indicator fed back from the user device (11), the network device estimates the weak interference noise matrix of the user device according to the downlink channel quality indicator or the interference indicator fed back from the user device (12), the network device obtains the time-frequency channel matrix of the service cell and the time-frequency strong interference matrix of the strong interference cell, and obtains the time-frequency interference noise matrix of the user device according to the estimated weak interference noise matrix and the time-frequency strong interference matrix (13), the network device estimates the downlink channel quality according to the time-frequency channel matrix and the time-frequency interference noise matrix (14).