Compared with conventional multiple-input multiple-output (MIMO), massive MIMO system with tens or even hundreds of antennas is able to give better performance in capacity and spectral efficiency, which is a promising technology for 5G. Considering this, massive MIMO has become a hot research topic all over the world. In this paper, the channel measurements and models of massive MIMO in recent years are summarized. Besides, the related 256 antenna elements with 200 MHz bandwidth at 3.5 GHz proposed by our team, the verification of rationality of the measurement method, and the spatial evolution of clusters in mobile scenario are provided.

In ultra-dense heterogeneous networks, the co-channel interference between small cells turns to be the major challenge to cell throughput improvement, especially for cell edge users. In this paper, we propose a distributed frequency resource allocation approach for interference cancellation, which allocates appropriate frequency resources when a small cell is switched on to reduce the co-channel interference to its neighboring small cells. This frequency resource pre - allocation aims at avoiding co-channel interference between small cells and improving users’throughput. The simulation results show that our proposed scheme can effectively reduce the co-channel interference and achieve considerable gains in users’ throughput.