| 摘要: |
| 为了消除短波OFDM通信中的频率偏移问题，对差分OFDM信号进行了分析，并对最大
后验概率（MAP）译码的性质进行了研究，提出了一种似然比最大化的迭代盲频偏估计
算法。由于该算法充分利用了软译码得到的似然比信息，因此可以实现最优信号检测。计算
机仿真证明了该算法的有效性。进行了短波OFDM信号通信实验，得到了实测数据。实测数据
检测结果表明，该算法的误码率性能随着迭代次数的增加而提高，且一发两收系统性能要比
单发单收系统性能至少提高2 dB。 |
| 关键词: 短波通信 差分OFDM调制 MAP译码 盲频偏估计 |
| DOI： |
|
| 基金项目: |
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| A Log likelihood Ratio Maximization Blind Frequency Offset Estimation Algorithm in OFDM Systems |
| REN Xue-feng,JIANG Yu-zhong,LIU Xuan |
| (Department of Communication Engineering,Naval University of Engineering,Wuha
n 430033,China) |
| Abstract: |
| In order to remove the frequency offset in HF OFDM communica
tions，the differential OFDM systems are analysed, and the property of M
AP decoding is studied. A loglikelihood ratio maximization blind frequency off
set estimati
on algorithm is proposed. This algorithm can achieve the best demodulation beca
use the likelihood ratio of information is used adequately. The simulations show
that this algorithm is effective.HF communication experiment is performe
d, and practical information is achieved. Using this algorithm to demodulate pra
ctical information demonstrates that this algorithm can enhance the BER performa
nce
with the increasing iterative times, and the performance of onetransmitter/two
receiver system is better than that of onetransmitter/onereceiver system a
t least
2 dB. |
| Key words: HF communication differential OFDM modulation MAP decoding blind frequency offset estimation |
