6:Opportunistic Communication and Multiuser ECS Diversity Wireless F oundations Performance:Low SNR 3 2.5 2 CSIR Full CSI.. 1.5 1 050 -15 -10 -5 0 5 10 SNR [dB] At low SNR,capacity can be greater when there is fading. Fundamentals of Wireless Communication,Tse&Viswanath 9 6: Opportunistic Communication and Multiuser Diversity Fundamentals of Wireless Communication, Tse&Viswanath 9 Performance: Low SNR At low SNR, capacity can be greater when there is fading