自由空间光通信中的极化码凿孔方法研究

Study on polarization code puncturing of FSO

为降低大气湍流效应造成的自由空间光通信系统性能的恶化,极化码成为了自由空间光通信领域的研究热点。针对服从双伽马分布的大气强湍流信道模型,提出了一种新颖的极化码凿孔方法,使用矩阵指数来衡量凿孔效果。对原始极化码生成矩阵的行和列进行重排来构造新的生成矩阵,基于新的生成矩阵给出了简单易行的凿孔方法。在强湍流大气信道下对本文的凿孔方法和传统凿孔方法进行了仿真,结果表明,相比传统凿孔方法,本文提供的凿孔方法在10e-5误码率时可以获得约0.4dB的编码增益,可有效提升自由空间光通信在强湍流条件下的性能表现。

To reduce the FSO system performance deterioration caused by atmospheric turbulence,polarization code becomes the focus of free spatial optical communication（ FSO） field. For the atmospheric strong turbulence channel model based on double-gamma distribution,a novel polarization code puncturing method is proposed in this paper,which uses matrix exponential to measure the effect of puncturing. Rearrange rows and columns of the original polarization matrix to construct new generator matrix,give a simple puncturing method based on new generator matrix. The performance of the method is simulated and analyzed. Simulation results show that compared to traditional puncturing methods,the proposed method can achieve about 0. 4 dB coding gain at 10 e-5 bite error rate（ BER）,which can efficiently improve the performance of FSO in strong turbulence channel.