| 摘要: |
| 采用随机共振解调微弱MFSK信号解决了传统解调方法误码率高的问题。
根据大噪声环境下信号能借助噪声能量发生随机共振这一理论，先将微弱MFSK信号通过双稳
态随机共振系统以提高其信噪比，对随机共振系统的输出信号用FFT来区分每段信号的载波
频率，最后依据判决准则解调MFSK信号。当信噪比较高时，可向信号中人为添加白噪
声来使之适用于该解调方法。MATLAB仿真结果表明，该方法能成功解调信噪比最低为
-23 dB的2FSK信号和-25 dB的8FSK信号，而这是传统相干解调方法所无法达到的。 |
| 关键词: 随机共振 频率压缩 微弱MFSK信号 解调 数据采集窗 |
| DOI： |
|
| 基金项目:国家自然科学基金资助项目（61071196）；国家自然科学基金-
中物院NSAF联合基金项目（10776040）；教育部新世纪优秀人才支持计划（NCET-10-0927）
；信号与信息处理重庆市市级重点实验室建设项目（2009CA2003）；重庆市自然科学基金项
目（2009BB2287，2010BB2398，2010BB2411） |
|
| Demodulation of Weak MFSK Signal Based on Stochastic Resonance |
| WEI Shi-peng,ZHANG Tian-qi,YU Xi,GAO Chun-xia |
| (Chongqing Key Laboratory of Signal and Information Processing,Chong
qing University of Posts and Telecommunications, Chongqing 400065, China) |
| Abstract: |
| Using the stochastic resonance to demodulat
e the weak MFSK(M-ary Frequency-shift Keying) signal solves the high BER(Bit Er
ror Rate) in traditional demodulati
on methods. Based on the theory that the signal can get help from the no
ise′s energy to generate stochastic resonance,the weak MFSK signal is put int
o the stochastic resonance system to increase its SNR(Signal-to-noise Ratio), th
en the FFT(Fast Fourier Transform) is used to distinguish the two ca
rriers of the signal, finally the MFSK signal is demodulated according to judg
ment criteria.When the SNR is high,the white noise can be added into the signal
to suit for this method. The MATLAB simulation results show that this method can
successfully demodulate the 2FSK signal in -23 dB and 8FSK signal in -25
dB, and conventional coherent demodulation can not achieve the result. |
| Key words: stochastic resonance frequency compression weak MFSK signal demodulation dat
a acquisition window |
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