Proportional fair scheduling schemes for highly transmit correlated channels

In this paper, we consider the downlink heterogeneous scenario with highly transmit correlated channels, and propose two kinds of the statistical channel state information (SCSI) aided proportional fair scheduling (PFS) schemes: 1) signal-to-noise ratio based PFS (SNR PFS) scheme and 2) SNR PFS scheme with threshold, which determine the preferred beamforming vector and proportional fair index by exploiting the SCSI and only send back the instantaneous channel quality indicator (CQI) at each timeslot. Although the SNR PFS scheme only requires little feedback overhead and low computational complexity, the performance of the SNR PFS scheme is similar to the conventional scheme (i.e., codebook-based PFS scheme), which achieves a tradeoff between system throughput and fairness. However, with the increasing number of users, a large number of CQI feedbacks will increase the signaling burden. To overcome this obstacle, the proposed SNR PFS scheme with threshold which limits the CQI feedbacks with poor channel quality would hardly affect the performance of the system. Finally, Our simulation results show that the average rate of the SNR PFS scheme with β = In (K/5) approaches to that of the SNR PFS scheme, while it has less limited feedback capacity than the SNR PFS scheme.