Improvement in the Performance of Multiuser Multi Cell Interference Alignment with Pair Selection

In this paper we investigate the performance of multi user interference alignment based transmit precoding with pair selection in a MIMO-OFDM based closed loop downlink cellular system. For this purpose we propose two pair selection schemes. One is based on the maximization of alignment gain and the other is based on the maximization of estimated SINR. Our schemes are suboptimal but we show with the help of extensive simulation results that they provide considerable gains in the mean cell rate performance of the system. We compare the results of our proposed schemes with two other baseline pair selection schemes based on the nearly orthogonal users selection. The results show that our proposed schemes provide higher and sustainable performance gains to the IA based transmission. We also compare the performance of the IA based transmit precoding with other baseline multiuser precoding schemes using the pair selection algorithms. The simulation results illustrate that the IA based precoding scheme outperforms other baseline precodings also with multiuser selection diversity.