| 摘要: |
| 高斯滤波最小频移键控（Gaussian Filtered Minimum Shift Keying，GMSK）具有较好的旁瓣衰减性能和恒包络特性，适用于航天通信领域，其通信信息速率可以任意设置无疑能够拓宽其应用范围。但因为GMSK调制采用的高斯滤波器的特性与信号的3 dB带宽、符号的持续时间有关，所以信息速率的任意性增加了GMSK调制与解调的复杂性。在利用Laurent分解法分析任意信息速率下GMSK信号调制、解调原理的基础上，提出了基于Cordic算法与查表法相结合的调制方法，以及基于改进的分组式Viterbi算法的解调方法。通过Matlab对提出的方法进行了仿真验证并利用FPGA硬件平台实现该算法，最后使用误码仪测试了信号的传输特性。实验结果表明，该方法可以实现任意信息速率的GMSK调制与解调，具有一定的工程应用价值。 |
| 关键词: GMSK Laurent分解 任意信息速率 Viterbi算法 |
| DOI： |
|
| 基金项目:国家自然科学基金资助项目（61461013）；广西无线宽带通信与信号处理重点实验室基金（GXKL06160103） |
|
| Modulation and Demodulation Method for GMSK Signals with Arbitrary Information Rate |
| TANG Zhiling,LI Cheng,LI Simin |
| (1.School of Information and Communication,Guilin University of Electronic Technology,Guilin 541004,China;2.School of Electrical and Information Engineering,Guangxi University of Science and Technology,Liuzhou 545006,China) |
| Abstract: |
| For its good sidelobe attenuation performance and the characteristic of constant envelope,Gaussian filter minimum frequency shift keying(GMSK) is suitable for aerospace communications.The communication information rate of GMSK can be arbitrarily set,which can undoubtedly broaden its application range.However,the characteristics of the Gaussian filter,used in GMSK modulation,are related to the 3 dB bandwidth of the signal and the duration of the symbol,so the arbitrary nature of the information rate increases the complexity of GMSK modulation and demodulation.On the basis of Laurent decomposition analysis for the modulation and demodulation of GMSK signals at any information rate,the modulation method based on Cordic algorithm combined with table lookup method,and the demodulation method based on the improved grouped Viterbi algorithm are proposed in this paper.The proposed method is verified by Matlab simulation and realized by FPGA hardware platform.Finally,the signal transmission performance is tested by error code instrument.The experimental results show that this method can achieve GMSK modulation and demodulation at any information rate,thus certainly having engineering application value. |
| Key words: GMSK Laurent decomposition arbitrary information rate Viterbi algorithm |
《电讯技术》编辑部 