Title :
Improve spectrum efficiency based on variable-power AMC and ARQ for OFDM systems
Author :
Chu, Yung-Hung ; Kuo, Yu-Chin ; Tseng, Shu-Ming ; Hsu, Yueh-Teng
Author_Institution :
Dept. of Electron. Eng., Nat. Taipei Univ. of Technol., Taipei, Taiwan
Abstract :
To improve spectrum efficiency (SE), the adaptive modulation and coding (AMC) and automatic repeat request (ARQ) scheme have been combined for OFDM systems. In this paper, we add variable power subject to power constraint in each AMC mode. We use KKT optimization algorithm to get the optimal transmit power and AMC mode boundaries. The numerical results show that the average SE is increased by about 0.3 bits/sec/Hz for OFDM systems with Nakagami fading with parameter m=2 when SNR is around 15dB and the retransmission is once.
Keywords :
Nakagami channels; OFDM modulation; adaptive codes; adaptive modulation; automatic repeat request; optimisation; radio spectrum management; AMC; ARQ; KKT optimization algorithm; Nakagami fading; OFDM systems; SE; adaptive modulation and coding; automatic repeat request; power transmission; spectrum efficiency; Adaptation model; Automatic repeat request; Signal to noise ratio; OFDM; spectrum efficiency; transmitter power control;
Conference_Titel :
Intelligent Computing and Integrated Systems (ICISS), 2010 International Conference on
Conference_Location :
Guilin
Print_ISBN :
978-1-4244-6834-8
DOI :
10.1109/ICISS.2010.5657084
