ICIC-based Small Cell On/Off Schemes for LTE-A Networks

In Small Cell Enhancement (SCE) scenarios, the network exhibit dramatic dynamics in load, user distribution and interference due to the fact that a large number of small cells coexist in the coverage area of the macro cells. Small cell on/off is a key technology to adapt to the network dynamics. In this paper, we propose two small cell on/off algorithms that fully take into consideration the interference between the small cells to decide which cells to turn on/off. The first algorithm is an ideal dynamic small cell on/off scheme which finds the small cells that are causing serious interference and schedule these small cells to take turns in transmitting their data on every subframe. The second proposed algorithm is a semi-static small cell on/off algorithm which operates in two steps. First, a small cell is turned off if it causes serious interference and the performance gain brought by it being on is marginal. Then, users are ordered according to their received maximum signal-to-interference-and-noise (SINR) over all cells that are still on. Users with a higher maximum SINR choose the cell that offers the maximum SINR, and the remaining users choose a cell that has a relatively low load and offers a relatively high SINR. Simulations show that the proposed schemes have better performance in terms of average user perceived throughput and tail user perceived throughput compared with existing schemes.