Title :
Block-wise adaptive modulation for OFDM WLAN systems
Author :
Hwang, Yin-Tsung ; Tsai, Chen-Yu ; Lin, Cheng-Chen
Author_Institution :
Dept. of Electron. Eng., Nat. Yunlin Univ. of Sci. & Technol., Taiwan
Abstract :
Adaptive modulation has been shown to be effective in performance enhancement for multi-carrier wireless communication. In this paper we present an adaptive modulation framework for the OFDM based IEEE 802.11a wireless LAN system. The goal is to increase the data transmission rate subject to fixed transmission power and the upper bound constraint of packet error rate. Two adaptive modulation schemes are proposed and both use the estimated subband SNR values to adjust the modulation scheme in a blockwise manner. The simulation results indicate both schemes can effectively increase the average data rate up to 147% under the 802.11a model. The performance improvement is even prominent for severe frequency selective fading environments.
Keywords :
IEEE standards; OFDM modulation; adaptive modulation; channel capacity; data communication; error statistics; fading channels; wireless LAN; IEEE 802.11a; OFDM; WLAN systems; block-wise adaptive modulation; data transmission rate; estimated subband SNR; frequency selective fading; multi-carrier wireless communication; packet error rate; performance enhancement; wireless LAN; Adaptive systems; Bit error rate; Bit rate; Data communication; Error analysis; Fading; Iterative algorithms; OFDM modulation; Wireless LAN; Wireless communication;
Conference_Titel :
Circuits and Systems, 2005. ISCAS 2005. IEEE International Symposium on
Print_ISBN :
0-7803-8834-8
DOI :
10.1109/ISCAS.2005.1466031
