Improved Diversity with Limited Feed back for more than two users

We consider interference cancellation for a system with more than two users when users know each other channels. The goal is to utilize multiple antennas to cancel the interference without sacrificing the diversity or the complexity of the system. in the literature, it was shown how a receiver with two receive antennas can completely cancel the interference of two users and provide a diversity of 2 for users with two transmit antennas. Unfortunately, the scheme only works for two users. Recently it was shown that  a system to achieve interference cancellation and full diversity with low complexity for any number of users and  with any number of transmit and receive antennas  In this paper our main idea is to design precoders, using the channel information, to make it possible for different users to transmit over orthogonal directions. Then, using the orthogonality of the transmitted signals, the receiver can separate them and decode the signals independently. Next, we extend the result for limited feedback systems to improve the diversity in the applied conditions. Simulation results show that the proposed precoder outperforms the previous work and improved diversity results using limited feedback. This paper is an  extension of scheme in[1].

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