Title :
MIMO Link Adaptation in Mobile WiMAX Systems
Author :
Muquet, Bertrand ; Biglieri, Ezio ; Sari, Hikmet
Author_Institution :
Sequans Commun., Paris
Abstract :
Mobile WiMAX systems are based on the IEEE 802.16e specifications, which include two mandatory MIMO profiles for the downlink. One of these is Alamouti´s space-time code (STC) for transmit diversity, and the other is a 2times2 spatial multiplexing MIMO scheme. In this paper, we compare the two schemes assuming that the latter employs maximum-likelihood detection. The analysis shows that at the same spectral efficiency, Alamouti´s STC combined with maximum-ratio combining (MRC) at the receiver significantly outperforms the 2times2 spatial multiplexing scheme at high values of the signal-to-noise ratio (SNR). Next, selection of a MIMO option is included in link adaptation to maximize network capacity, and operating SNR regions are determined for different modulation, coding and MIMO combinations.
Keywords :
MIMO communication; WiMax; diversity reception; maximum likelihood detection; mobile radio; radio receivers; space-time codes; Alamouti´s STC; Alamouti´s space time-codes; MIMO link adaptation; maximum-likelihood detection; maximum-ratio combining; mobile WiMAX systems; signal-to-noise ratio; spatial multiplexing scheme; spectral efficiency; Base stations; Bit error rate; Communications Society; Diversity reception; Downlink; MIMO; Mobile communication; Modulation coding; Physical layer; WiMAX;
Conference_Titel :
Wireless Communications and Networking Conference, 2007.WCNC 2007. IEEE
Conference_Location :
Kowloon
Print_ISBN :
1-4244-0658-7
Electronic_ISBN :
1525-3511
DOI :
10.1109/WCNC.2007.340
