Study of Certain Subband-based Adaptive Modulation Schemes in an OFDM System
In applying adaptive schemes to an OFDM system to adaptively adjust the transmission format based on channel state information, a practical scheme would group the subcarriers into similar-quality subbands to reduce the associated modem mode-signaling requirements. One way to determine the modulation mode for a specific subband is based on the average signal-to-noise ratio (SNR) of the subband. To find the optimal switching levels, knowledge of the probability density function of this average SNR is required. Another popular way to determine the modulation mode is based on the SNR of the worst subcarrier of the suband, which may represent an overconservative choice of order statistic. This approach can be extended to deploying other statistic as well, for example, the second or the third worst statistic. Analysis of the above approaches is the focus of this study, and performances of these schemes are compared through numerical simulations.
L. J. Shi L. Rong R. F. Lin Y. Du
The Electromagnetics Academy at Zhejiang University, Zhejiang University, Hangzhou 310058, China Shanghai Research Center for Wireless Communications, Shanghai 200050, China
国际会议
Progress in Electromagnetics Research Symposium 2007(2007年电磁学研究新进展学术研讨会)(PIERS 2007)
北京
英文
787-790
2007-03-26（万方平台首次上网日期，不代表论文的发表时间）