1st International ICST Conference on Communications and Networking in China

Research Article

Constant-Power Adaptive QAM in High Delay Spread Environments

  • @INPROCEEDINGS{10.1109/CHINACOM.2006.344759,
        author={Xiao-Hong  Shan and Guang-Guo  Bi},
        title={Constant-Power Adaptive QAM in High Delay Spread Environments},
        proceedings={1st International ICST Conference on Communications and Networking in China},
        publisher={IEEE},
        proceedings_a={CHINACOM},
        year={2007},
        month={4},
        keywords={Adaptive modulation time delay spread average BER average throughput.},
        doi={10.1109/CHINACOM.2006.344759}
    }
    
  • Xiao-Hong Shan
    Guang-Guo Bi
    Year: 2007
    Constant-Power Adaptive QAM in High Delay Spread Environments
    CHINACOM
    IEEE
    DOI: 10.1109/CHINACOM.2006.344759
Xiao-Hong Shan1,*, Guang-Guo Bi1
  • 1: National Mobile Communications Research Lab, Southeast University, Nanjing 210096, China
*Contact email: xiao_hong_shan@seu.edu.cn

Abstract

Constant-power constant-symbol-rate adaptive quadrature amplitude modulation (AQAM) system with four modes is analyzed in high delay spread environments. The ratio of rms delay spread to symbol period is from 0.02 to 0.2. The average bit-error-rate (BER) and throughput are investigated subject to the instantaneous BER constraint and the average BER constraint. Results show that an increase in power or a reduction in delay spread will lead to the increase of the average throughput under the two constraints, whereas they will not necessarily result in a decrease in the average BER under the instantaneous BER constraint. The superiority to individual QPSK mode is investigated in the delay spread immunity at last.