Multiuser Scheduling for MIMO-OFDM Systems with Continuous-Rate Adaptive Modulation

In this paper, we present a multiuser scheduling technique for MIMO-OFDM system over multipath frequency- selective fading channels to exploit the multiuser, space and frequency diversities. A continuous-rate adaptive modulation is employed to increase the spectral efficiency of the system. A proportional fair scheduler is also considered to maintain the fairness among the users while exploiting the multiuser diversity. We also use a scheme to reduce the required feedback channel information. Using mathematical analysis and numerical simulations, the significant advantages of the proposed scheme have been shown. It is also shown that when the number of active users is moderately high and is above 30, even 10% feedback load is sufficient to get the benefits of the proposed scheme.