Optimal Feedback Updating Period for Coordinated Multi-Point Transmission Schemes

This work concerns a limited feedback scheme taking into account the channel time-correlation during the feedback design in slow fading environment. We consider the Coordinated MultiPoint (COMP) system model with other-cell interference (OCI). We determine the feedback updating period which is triggered by the transmitters to enable the receiver to send the CSI. This updating period is function of the channel temporal correlation, available feedback bits, and the number of transmit antennas. An optimal updating period is derived such that it guarantees that the average signal-to-interference-and-noise ratio (SINR) is greater than or equal to that of the conventional feedback scheme that does not adapt its feedback period to the temporal correlation. The numerical results show performance improvement in terms of overall capacity and feedback overhead reduction when comparing the proposed adaptive scheme with conventional feedback approaches.