基于Turbo码的空间激光脉冲时间传递方法

Time transfer method of space laser pulse based on Turbo code

激光信号在传输时会受到大气衰减与大气湍流等因素的干扰,导致授时误码率较高,影响时间传递的准确性,为此提出基于Turbo码的空间激光脉冲时间传递方法。构建激光脉冲信道与链路传输模型,设计信道编码,降低噪声对时间传递信号的干扰。依据Turbo码的编码原理,使交织器满足交织前后序列相关性最小的条件。在此基础上,建立双向测量模型,预测时间传递误差,并通过时延修正方法获取钟差表达式,计算其中的未知参数,达到时间传递的目的。实验结果表明,所设计方法具有误码率低,编码速率高等优点,可以更好地解决路径时延问题。

When laser signal is transmitted,it will be interfered by atmospheric attenuation,turbulence and other factors,which will lead to high error rate of timing and affect the accuracy of time transmission.Therefore,a time transmission method of space laser pulse based on Turbo code is proposed.The transmission model of laser pulse channel and link is constructed,and the channel coding is designed to reduce the interference of noise on time transmission signal.According to the coding principle of Turbo code,the interleaver satisfies the condition of minimum sequence correlation before and after interleaving.On this basis,the two-way measurement model is established to predict time transfer error,and the clock difference expression is obtained by time delay correction method,and the unknown parameters are calculated to achieve the purpose of time transfer.The experimental results show that the design method has advantages of low bit error rate and high coding rate,which can better solve path delay problem.