On the sum-rate performance and trade-off in relay-aided IA with outdated CSIT

In the past few years, extensive research has focused its attention on interference alignment (IA) methods that are aimed at improving the interference networks potential. However, the channel state information (CSI) precision has a correlation with the functionality of IA. When the CSI is completely outdated then there is a possibility that performance effectiveness and gain of IA could be lost. In the current study, a completely outdated source-to-relay CSI within multi-user network is considered followed with the introduction of a collaborative relay system within such a situation to assist in improvement of the networks freedom levels. By examining various outdated CSI situations at transmitter (CSIT), the trade-off involving relay-aided IA (RIA) alongside non-relay-aided IA (NRIA) is obtained. Additionally, the total RIA rate alongside covariance-supported channel estimator is examined.