SINR Order Statistics in OFDMA Systems
In orthogonal frequency division multiple access downlink, the Signal-to-Interference-Noise Ratio (SINR) of every sub-band at each user is estimated with the aid of pilots and the channel quality (some function of SINR's) is fed back to the Base Station (BS). This information is utilized by the BS for downlink scheduling. However, the SINR of the bands at each user are correlated due to the common interfering BSs. In this paper, the authors obtain the order statistics of band SINR's by considering the co-channel interference and taking the correlations of interference across the bands into consideration. The order statistics are then used to analyze a best-m band feedback scheme, in which every users reports the index of their best-m bands to the BS.