On the Sum Rate of Fair Resource Allocation With Selective Feedback

Opportunistic scheduling exploits the multiuser diversity to improve the performance of wireless communications. The scheduling gain is enabled by the channel feedback sent from the receiver to the transmitter. In this paper, we consider the so-called opportunistic cumulative distribution function (CDF) scheduling with threshold-based selective feedback in the orthogonal frequency division multiple access downlink system. Among opportunistic scheduling techniques, the CDF scheduling is known to provide multiuser diversity gain while maintaining fair radio resource sharing among users. We first derive the exact and asymptotic average sum rates assuming antenna selection at transmitters. The expressions are valid for arbitrary number of inter-cell interference and number of transmit antennas. Moreover, a closed-form approximation for the user rate distribution is calculated using the exact moments of the user sum rate. The approximation is shown to provide an accurate estimate for the rate distribution, and the results can be utilized in rate adaptation at the transmitter.