非二位元LDPC編碼跳頻系統利用多樣性線性組合在多頻率跟隨干擾下的性能分析

Performance Analysis of A Non-binary LDPC Coded FH System Using Linear Diversity Combining Detection under Multi-tone Follower Jamming

許志弘(Chih-Hung Hsu)

指導教授 ： 李世凱

元智大學/電機通訊學院/通訊工程學系/碩士(2011年)

https://doi.org/10.6838/YZU.2011.00253

摘要

本篇論文利用非二位元的奇偶校驗碼(Non-binary LDPC Codes)來對抗蓄意的多頻率跟隨干擾於跳展頻系統。論文中計算其通道容量，了解多頻率跟隨干擾對於通訊品質的影響程度，並使用非二位元奇偶校驗碼的軟式解碼方式，分別探討在高斯白雜訊(AWGN)及瑞雷衰減通道(Rayleigh Fading Channel)下的機率初始值，著重於不同碼率的非二位元規則性奇偶校驗碼對於兩根單頻率跟隨干擾(2-tone Follower jamming)的性能分析。另外，我們使用比例門檻測試(Ratio Threshold Test)技術來降低軟式解碼機率初始值的計算複雜度，並提出多樣性線性組合(Linear Diversity Combining) 技術來增強訊號能量，降低多頻率跟隨干擾對訊號所造成的影響。模擬結果利用這些技術可提高非二位元奇偶校驗碼的編碼碼率，並達到對抗多頻率跟隨干擾的目的。

關鍵字

多樣性線性組合 ； 低密度奇偶校驗碼 ； 多頻率跟隨干擾

並列摘要

This thesis discusses about using non-binary LDPC codes to resist the intentional multi-tone follower jamming for frequency hopping systems. We calculate the capacities for several jamming channels so that we can evaluate the influences to communication quality. When the channels are also Rayleigh faded or with AWGN, soft decoding is applied to the decoder and the probabilities of channel values for decoding are theoretically formulated. We especially focus on resisting two tone follower jamming by using different code rates of non-binary regular LDPC codes. By using the technique of ratio threshold test (RTT), the calculation of the probabilities of channel values can be simplified. Based on RTT, we propose a linear diversity combing detector to combat multi-tone follower jamming. Simulation results show that the code rates of non-binary LDPC codes can be increased when using these techniques and the system can achieve the purpose on resisting the multi-tone follower jamming.

並列關鍵字

Non-binary LDPC ； Linear Diversity Combining ； RTT ； Follower jamming

參考文獻

[1] Howard H. MA, Margaret A. Poole, “Error-Correcting Codes Against the Worst-Case Partial-Band Jammer” Military Communications Conference, IEEE, vol. 1, pp.114-118, Feb. 1984.

[2] Q. Wang, T. A. Gulliver, V. K. Bhargava, “Coding for Fast Frequency Hopped Noncoherent MFSK spread spectrum communications under worst case jamming,” Military Communications Conference, vol. 1, pp.299-305, Oct. 1988.

[3] Geraniotis, E.“Effect of Worst case multiple partial-band noise and tone jammers on coded FH/SSMA systems,” Selected Areas in Communications, IEEE Journal, vol. 8, pp.613-627, May. 1990.

[4] Kang. J. H, Stark, W.E, “Turbo codes for noncoherent FH-SS with partial band interference,” Communications, IEEE Transactions, vol. 46, pp.1451-1458, Nov. 1998.

[5] Kah C. Teh, Wei Xia, “PERFORMANCE ANALYSES OF REED-SOLOMON CODED FFH/BFSK LINEAR-COMBINING RECEIVER OVER MULTITONE JAMMING AND AWGN CHANNELS,” MILCOM 2000. 21st Century Military Communications Conference, vol. 1, pp.149-153, Oct. 2000.