Reduced dimension superimposed precoder feedback for interference alignment

In this paper, analog feedback of precoder is proposed for K-user interference channel with equal number of antennas at transmitters and receivers. We also consider the superimposed pilot based training scheme where training pilots and feedback data are sent simultaneously. This scheme requires the same number of time slots as non-superimposed one. In addition to this framework, we propose reduced dimension precoder feedback by utilizing the unit norm of the precoder. This reduced dimension feedback with multiple antennas improves the precoder estimation at transmitters, which improves the sumrates of the system. The simulation results verify that this reduced dimension precoder feedback schemes decrease the rate loss, and improve the sumrate.