基于Vi t erbi-Vi t erbi算法原理,提出了一种适用于Square m-QAM相干光通信系统载波相位估计的改进算法,能够充分利用所有符号的相位信息进行载波相位估计。仿真分析表明,改进算法比现有其它算法复杂度更低,相位噪声容限更大,当BER=10-...基于Vi t erbi-Vi t erbi算法原理,提出了一种适用于Square m-QAM相干光通信系统载波相位估计的改进算法,能够充分利用所有符号的相位信息进行载波相位估计。仿真分析表明,改进算法比现有其它算法复杂度更低,相位噪声容限更大,当BER=10-3、SNR代价为2dB时,16-QAM和64-QAM允许的激光线宽分别为1.1MHz和0.25MHz。展开更多
The 16-ary quadrature amplitude modulation （16QAM） is a high spectral efficient scheme for high-speed transmission systems. To remove the phase ambiguity in the coherent detection system, differential-encoded 16QAM ...The 16-ary quadrature amplitude modulation （16QAM） is a high spectral efficient scheme for high-speed transmission systems. To remove the phase ambiguity in the coherent detection system, differential-encoded 16QAM （DE-16QAM） is usually used, however, it will cause performance degradation about 3 dB as compared to the conventional 16QAM. To overcome the performance loss, a serial concatenated system with outer low density parity check （LDPC） codes and inner DE-16QAM is proposed. At the receiver, joint iterative differential demodulation and decoding （ID） is carried out to approach the maximum likelihood performance. Moreover, a genetic evolution algorithm based on the extrinsic information transfer chart is proposed to optimize the degree distribution of the outer LDPC codes. Both theoretical analyses and simulation results indicate that this algorithm not only compensates the performance loss, but also obtains a significant performance gain, which is up to 1 dB as compared to the conventional non-DE-16QAM.展开更多
文摘基于Vi t erbi-Vi t erbi算法原理,提出了一种适用于Square m-QAM相干光通信系统载波相位估计的改进算法,能够充分利用所有符号的相位信息进行载波相位估计。仿真分析表明,改进算法比现有其它算法复杂度更低,相位噪声容限更大,当BER=10-3、SNR代价为2dB时,16-QAM和64-QAM允许的激光线宽分别为1.1MHz和0.25MHz。
基金supported by the National Natural Science Foundation of China(61171101)the State Major Science and Technology Special Projects(2009ZX03003-011-03)
文摘The 16-ary quadrature amplitude modulation （16QAM） is a high spectral efficient scheme for high-speed transmission systems. To remove the phase ambiguity in the coherent detection system, differential-encoded 16QAM （DE-16QAM） is usually used, however, it will cause performance degradation about 3 dB as compared to the conventional 16QAM. To overcome the performance loss, a serial concatenated system with outer low density parity check （LDPC） codes and inner DE-16QAM is proposed. At the receiver, joint iterative differential demodulation and decoding （ID） is carried out to approach the maximum likelihood performance. Moreover, a genetic evolution algorithm based on the extrinsic information transfer chart is proposed to optimize the degree distribution of the outer LDPC codes. Both theoretical analyses and simulation results indicate that this algorithm not only compensates the performance loss, but also obtains a significant performance gain, which is up to 1 dB as compared to the conventional non-DE-16QAM.
