During the reentry process, the plasma sheath covering the surface of the hypersonic aircraft will cause the amplitude attenuation and phase jitter of the communication electromagnetic waves. Channel parameters such as the electron density and collision frequency of the plasma sheath reflect the changing trend of the plasma sheath, and these parameters can be measured by physical means. However, these parameters cannot directly reflect the change of the channel communication ability and cannot directly serve the design of communication methods in the plasma sheath. Due to the particularity of the plasma sheath, the traditional channel estimation method for Additive White Gaussian Noise channels will no longer be applicable. This paper presents a channel capacity estimation method for dynamic plasma sheath. First, the plasma sheath is equivalent to a discrete input continuous output memoryless channel, and then the channel capacity expression is derived according to Shannon formula. Finally, the channel capacity of the dynamic plasma sheath is estimated by calculating the transition probability density function. The simulation results show that the channel capacity of the dynamic plasma sheath is affected by both the signal-to-noise ratio (SNR) and the dynamic parameters of the plasma sheath. When the electron density is small, the channel capacity is mainly affected by the SNR. As the electron density increases, the dynamic parameters of the plasma sheath gradually become the main factor affecting the channel capacity. This method is a theoretical analysis of the channel capacity when the channel parameters of the plasma channel are known, and it is meaningful for conducting the work of communication methods design.

中文翻译：

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动态等离子鞘管信道下PSK信道容量估计

在折返过程中，覆盖高超声速飞机表面的等离子体鞘层将导致通信电磁波的振幅衰减和相位抖动。等离子体鞘层的电子密度和碰撞频率等通道参数反映了等离子体鞘层的变化趋势，这些参数可以通过物理手段进行测量。但是，这些参数不能直接反映信道通信能力的变化，也不能直接用于等离子体鞘层中通信方法的设计。由于等离子护套的特殊性，用于加性高斯白噪声信道的传统信道估计方法将不再适用。本文提出了一种动态等离子体鞘的通道容量估计方法。第一，等离子体鞘等效于离散输入连续输出无记忆通道，然后根据香农公式推导通道容量表达式。最后，通过计算跃迁概率密度函数来估算动态等离子体鞘的通道容量。仿真结果表明，动态等离子体鞘层的通道容量受信噪比（SNR）和等离子体鞘层动态参数的影响。当电子密度小时，通道容量主要受SNR影响。随着电子密度的增加，等离子鞘层的动态参数逐渐成为影响通道容量的主要因素。当知道等离子通道的通道参数时，该方法是对通道容量的理论分析，