PROJECT TITLE :

Distributed Space–Time Interference Alignment With Moderately Delayed CSIT

ABSTRACT:

This paper proposes an interference alignment methodology with distributed and delayed channel state data at the transmitter (CSIT) for a category of interference networks. The core idea of the proposed technique is to align interference signals over time at the unintended receivers in a distributed manner. With the proposed technique, achievable tradeoffs between the add of degrees of freedom (total-DoF) and feedback delay of CSI are characterised in both the X-channel and three-user interference channel to reveal the impact on how the CSI feedback delay affects the total-DoF of the interference networks. A significant implication of derived results is that distributed and moderately delayed CSIT is useful to strictly improve the total-DoF over the case of no CSI at the transmitter in a very sure class of interference networks. For a class of X-channels, the results show how to optimally use distributed and moderately delayed CSIT to yield the identical total-DoF as instantaneous and international CSIT. Furthermore, leveraging the proposed transmission technique and the known outer certain results, the add-capability of the two-user X-channel with a specific set of channel coefficients is characterized among a continuing range of bits.