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Abstract-In a wireless network, with the aid of rate adaptation, multiuser diversity can be exploited by allowing the mobile user with the best channel to use the channel. However, the overhead that results from polling mobile stations to obtain channel state information (CSI) in large networks can outweigh the multiuser diversity gain. In this paper, we propose a wireless medium access control protocol, namely Multiuser Diversity with Capture (MDC), which explicitly employs the capture effect to obviate the overhead problem. We analyze the goodput performance of MDC and compare it with the Medium Access Diversity (MAD) scheme proposed in the literature. Our results show that MDC is effective in networks with radio receivers possessing reasonably good capture properties and in networks where the number of mobile stations is reasonably large.Index Terms-capture effect, MAC protocol, multiuser diversity, wireless LAN

In a wireless network, multiuser diversity can be exploited by allowing the mobile user with the best channel to use the channel. However, the overhead incurred in polling channel state information (CSI) can overshadow the multiuser diversity gain. In our previous work, we proposed a Multiuser Diversity with Capture (MDC) scheme to reduce the overhead by taking advantage of the fact that only the channel state information of the mobile station (MS) with the best channel is required to be available at the base station (BS). In this paper, we propose Fairer Multiuser Diversity with Capture (FMDC) to improve the fairness performance of MDC. We also develop a fairness measure for wireless systems that exploit multiuser diversity. By simulations, we evaluate the goodput and temporal fairness performance for FMDC, MDC and the Medium Access Diversity (MAD) schemes proposed in the literature. Our results show that with a small degradation in goodput performance, FMDC achieves much better fairness performance than MDC. Furthermore, FMDC achieves much better goodput performance than MAD, with comparable fairness performance.Index Terms-multiuser diversity, capture effect, IEEE 802.11a, channel state information, fairness

With the aid of rate adaptation, multiuser diversity can be exploited in wireless networks by allowing the mobile user with the best channel to use the channel. However, polling mobile stations to obtain channel state information in large networks can result in large overhead, outweighing the multiuser diversity gain. Multiuser Diversity with Capture (MDC) is a wireless medium access control protocol that explicitly employs the capture effect to overcome the overhead problem. In this paper, we analyse the goodput performance of MDC over Rayleigh fading channels and compare it with the Medium Access Diversity (MAD) scheme proposed in the literature. Our results show that MDC is effective in networks with radio receivers possessing reasonably good capture properties and in networks where the number of mobile stations is reasonably large.