中层海水水色三要素对水下量子通信性能的影响

Influence of the Three Elements of Water Color on the Performance of Underwater Quantum Communication in the Intermediate Seawater

为了研究中层海水中水色三要素对水下量子通信性能的影响,首先根据水色三要素的吸收和散射模型,提出了海水中叶绿素浓度、光量子信号波长和水下量子链路衰减的关系;然后针对退极化信道,分析了叶绿素浓度、光量子信号波长与信道容量、信道平均保真度和信道误码率之间的定量关系。仿真结果表明,传输距离为20 m,当叶绿素浓度分别为0.5 mg/m^3和1.5 mg/m^3时,水下量子通信信道容量、信道平均保真度、信道误码率依次分别为0.263 1和0.142 3,0.705 2和0.553,0.037 05和0.029 17.当波长分别为400nm和800nm时,通信信道容量、信道平均保真度、信道误码率依次分别为0.229 1和0.428 3,0.914 2和0.943 7,0.012 36和0.006 87。由此可见,叶绿素浓度和光量子信号波长对水下量子通信性能有显著的影响。应根据对海水水色三要素的探测情况,自适应调整系统的各项参数。

To investigate the influence of three elements of water color on the performance of underwater quantum communication in the intermediate seawater,we analyzed and scattering characteristics of three elements.And then according to the absorption and scattering model of three elements of water color,the relationship among the chlorophyll concentration,the wavelength and the underwater quantum link attenuation were obtained.According to the depolarizing channel,the quantitative relationship among chlorophyll concentration,wavelength and the channel capacity,the channel average fidelity and the quantum bit error rate were put out and simulated finally.Theoretical analysis and simulation results show that,if the distance is 20 m,the chlorophyll concentration is 0.5 mg/m^3 and 1.5 mg/m^3,the channel capacity,channel average fidelity and the channel bit error rate of underwater quantum communication will be 0.263 1 and0.142 3,0.705 2 and 0.553,0.037 05 and 0.029 17 respectively.If the wavelength is 400 nm and 800 nm,the above channel parameters will be 0.229 1 and 0.428 3,0.914 2 and 0.943 7,0.012 36 and0.006 87 respectively.It can be shown that,the chlorophyll concentration and the wavelength have significant effect on the performance of underwater quantum communication.Therefore,in the process of underwater quantum communication,in order to ensure the reliability of quantum communication in the intermediate water,the various indexes should be adjusted adaptively based on the detection of three elements of water color.