Embodiments of the present disclosure provide a method, device, radio network controller and chip for improving network quality. A signal of a user in a serving cell, detected by the same-frequency cell adjacent to the serving cell, is combined with a signal detected by the serving cell using a MCJD technology, so as to improve the signal quality of the user in the serving cell. The method of the present disclosure comprises: obtaining a first signal which belongs to a user terminal of a first cell and is detected by a base station of at least one second cell; combining the first signal with a second signal of the user terminal detected by a base station of the first cell to obtain a third signal; sending the third signal to a radio network controller. Therefore, the signal quality of the user in the first cell can be improved.