The users’signals in the service base station can be processed intensively, controlled and real-time managed jointly by cloud wireless with units access which can eliminate the internal interference inside the base station service area, and decrease the number of the wireless devices and the cost of the wireless access network. In this paper, the large scale antenna spatial modulation technology is applied to the Cloud Radio Access Network. The mutual information of the system is deduced when the input information of the system is discrete and uniformly distributed. The system simulation experiment is carried out. Results show that the performance gain of the BER and mutual information of large scale antenna spatial modulation systems in Cloud Radio Access Network are much higher than that existing in MIMO systems in cloud wireless access networks