Reduction of Threshold-Based Feedback in Multi-Cellular Cluster Networks

In this paper, a downward system has cell and dual frequency division characteristics has been considered in which each user send state information of information channel to its home station. Since the cooperation between all stations is not possible in practice, a number of stations are grouped into clusters and users should estimate their own channel by sending pilots to base station and feedback channel state information to the station. Until the station has no receive the channel information of all users, prevents to send it that it cause delay in sending data at downward system. The more the users increase, the greater delay occurs. In this study, two approaches are recommended in order to reduce the feedback of channel state information in a downward system. The basic idea of proposed approaches is that users are divided into two groups based on users’ channel power and their distance from the transmitter. An important issue in cooperative MIMO network is that the channel state information should be collected in a small fraction of channel bonding to have enough time to send the data and observed using a simulation. The effectiveness of the proposed method in order to reduce the feedback of channel state information on system performance is very low compared with other methods.