本論文中我們探討在快速跳頻/MFSK(Fast Frequency Hopping/Multiple Frequency Shift Keying, FFH/MFSK)通訊系統中,加上多音頻干擾後並經過通道,再使用不同的錯誤更正碼(Error Correcting Codes, ECC)並分析其效能。我們的系統所採取的通道為可加性白色高斯雜訊(Additional White Gaussian Noise, AWGN)和頻率選擇性雷利衰減(frequency selective Rayleigh fading)通道。在錯誤更正碼的使用上,分別是摺積碼(convolutional codes)與渦輪碼(turbo codes)。解碼器是採用遞迴解碼的方式。而我們為了比較各種編、解碼器的效能優劣,因此在效能分析方面是使用Extrinsic information transfer(EXIT) chart這個方法。另外本論文將模擬的是位元交錯二位元碼的效能。由電腦模擬結果可知,在遞迴解碼的時候,若是採用串接符元碼-遞迴解碼,效果會比沒有串接符元碼的好。至於錯誤更正碼解碼的部分,摺積碼的效能則是優於渦輪碼。
In this paper, we focus on FFH/MFSK communication systems. After adding multitone jamming and passing through the channel, we compare the performance in different error correcting codes. In our system, the channel we used are Additional White Gaussian Noise channel and Rayleigh selective fading channel. In the use of error correcting codes, we select using convolutional codes and turbo codes. And the decoder is iterative decoding. In order to compare with the performance of different encoder and decoder, so our performance analysis is use the method named Extrinsic Information Transfer (EXIT) chart. And in this paper, we simulate the performance of bit interleaving binary code. From the simulation result, the concatenated non-binary code is better than the without concatenated non-binary code. And the convolutional codes will have better performance than turbo codes.