Improved Frey Chaotic Digital Encoder for Trellis-Coded Modulation
Improved Frey Chaotic Digital Encoder for Trellis-Coded Modulation
复制标题
用于网格编码调制的改进弗雷混沌数字编码器
DOI：
10.1109/tcsii.2009.2020936
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
R. Quéré
中科院分区：
文献类型：
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作者：
C. Vladeanu;S. E. Assad;J. Carlach;R. Quéré
在这篇简报中，有限精度的非线性数字滤波器被分析为递归系统卷积（RSC）编码器。具有有限精度（N位的字长）的无限脉冲响应（IIR）数字滤波器是伽罗瓦域GF（2N）上的速率1 RSC编码器。对不同字长N的Frey混沌滤波器进行了分析，证明了通过适当的滤波器设计可以提高滤波器的格形性能。因此，提供了一个修改的定义的编码率，并提出了一种网格设计方法的弗雷滤波器，它包括减少编码率从1到1/2。这种网格优化部分地遵循Ungerboeck的规则，即，提高了存在噪声时编码混沌传输的性能。事实上，它表明，对于相同的频谱效率，修改后的弗雷编码器优于原始弗雷编码器只有N = 2。为了显示这些非线性编码器的潜力，证明了GF（4）上的特定非线性数字滤波器等效于GF（2）常规最优RSC编码器。估计的符号错误率（SER）的所有建议的计划，结果显示预期的编码增益相比，其等效的非编码和线性版本。
In this brief, nonlinear digital filters with finite precision are analyzed as recursive systematic convolutional (RSC) encoders. An infinite-impulse-response (IIR) digital filter with finite precision (wordlength of N bits) is a rate-1 RSC encoder over a Galois field GF(2N). The Frey chaotic filter is analyzed for different wordlengths N, and it is demonstrated that the trellis performances can be enhanced by proper filter design. Therefore, a modified definition for the encoding rate is provided, and a trellis design method is proposed for the Frey filter, which consists of reducing the encoding rate from 1 to 1/2. This trellis optimization partially follows Ungerboeck's rules, i.e., increasing the performances of the encoded chaotic transmission in the presence of noise. In fact, it is demonstrated that for the same spectral efficiency, the modified Frey encoder outperforms the original Frey encoder only for N = 2. To show the potential of these nonlinear encoders, it is demonstrated that a particular nonlinear digital filter over GF(4) is equivalent to a GF(2) conventional optimum RSC encoder. The symbol error rate (SER) is estimated for all the proposed schemes, and the results show the expected coding gains as compared to their equivalent nonencoded and linear versions.