基于算数编码的概率星座整形技术的研究

Research on Probabilistic Constellation Shaping Technology Based on Arithmetic Coding

针对超100G光网络中信道受限问题,提出了一种基于算数编码的速率可调正交幅度调制(QAM)概率星座整形(PCS)编码调制方案,使光网络传输容量更接近香农极限,并且提高信号的噪声恢复能力。发送端由分布匹配器和FEC编码器组成,分别负责对信号进行概率整形和信道编码的任务,系统通过改变分布匹配器的概率分布来调节速率。在接收端,FEC解码器和反向分布匹配器解码噪声信号恢复数据。实验结果表明,16QAM采用概率星座整形方案后,OSNR的增益为0.382dB、互信息增益为0.09bit/symbol。证明该PCS方案能够优化光信噪比(OSNR),提升传输容量,同时误码率明显低于标准16QAM,整形信号对噪声有更好的恢复能力。

Aiming at the problem of channel limitation in beyond-100 G optical network,this paper presents a rate adjustable Probabilistic Constellation Shaping(PCS) coding modulation scheme for Quadrature Amplitude Modulation(QAM) based on arithmetic coding,which makes the transmission capacity of optical network closer to Shannon limit and improves signal noise resilience. At the transmitter, the concatenation of a distribution matcher and a FEC encoder performs probabilistic signal shaping and channel coding,and the system adjusts the rate by changing the probability distribution of the distribution matcher. At the receiver, the FEC decoder and reverse distribution matcher decode the noise signal recovery data.Experimental results showed that the gain of OSNR was 0.382 dB and the gain of mutual information was 0.09 bit/s ymbol after 16 QAM adopted probabilistic constellation shaping scheme. It is proved that PCS can optimize the optical signal-to-noise ratio(OSNR) and improve the transmission capacity. Meanwhile, the bit error rate is significantly lower than the standard 16 QAM, so the shaping signal has better noise resilience.