Throughput Analysis of Opportunistic Feedback for Downlink Multiuser Diversity with Capture Effect

An opportunistic feedback protocol has been proposed in the literature to achieve multiuser diversity for the downlink transmission of a multiuser wireless system. In this letter, through theoretical analysis and extensive simulations, it is shown that the capture effect can have a significant impact on system throughput. It is also shown that, to achieve optimal throughput, the number of minislots used for opportunistically finding a user in the protocol should not be too large due to the overhead induced by the control packets.