arXivDaily arXiv每日学术速递 周一至周五更新
北美退伍军人节(Veterans Day),12 日无更新
arXiv cs/0411036cs.ITmath.IT
收藏

一阶滑动平均高斯信道的反馈容量

Feedback Capacity of the First-Order Moving Average Gaussian Channel

Young-Han Kim

摘要:

平稳高斯加性噪声信道的反馈容量一直是开放的,除了噪声是白噪声的情况。在这里,我们发现的反馈容量的平稳的一阶移动平均加性高斯噪声信道的封闭形式。具体地说,信道由$Y_i = X_i + Z_i,$ $i = 1, 2, ...,$给出,其中输入$\{X_i\}$满足功率约束,并且噪声$\{Z_i\}$是第一-本文证明了该信道的反馈容量为$Z_i = αU_{i-1} + U_i,$,其中$x_0$是方程$i = 0,1,....$的唯一正根,$ρ$是平均输入功率与平均输入功率之比将每次传输的噪声更新$U_i$的方差与噪声更新的方差进行比较。最佳编码方案与Schalkwijk和Kailath针对加性高斯白噪声信道的简单线性信令方案并行--发射机在通信开始时发送实值信息承载信号,随后通过线性平稳一阶自回归滤波器处理反馈噪声信号来细化接收机的误差。最大似然解码产生的错误概率在通信的持续时间内以双指数方式衰减。一阶移动平均高斯信道的这种反馈能力在形式上与Butman、Wolfowitz和Tiernan研究的一阶\emph{autoregressive}高斯噪声信道的最佳已知可实现速率非常相似,尽管后者的最优性尚未建立。

英文摘要:

The feedback capacity of the stationary Gaussian additive noise channel has been open, except for the case where the noise is white. Here we find the feedback capacity of the stationary first-order moving average additive Gaussian noise channel in closed form. Specifically, the channel is given by $Y_i = X_i + Z_i,$ $i = 1, 2, ...,$ where the input $\{X_i\}$ satisfies a power constraint and the noise $\{Z_i\}$ is a first-order moving average Gaussian process defined by $Z_i = αU_{i-1} + U_i,$ $|α| \le 1,$ with white Gaussian innovations $U_i,$ $i = 0,1,....$ We show that the feedback capacity of this channel is $-\log x_0,$ where $x_0$ is the unique positive root of the equation $ ρx^2 = (1-x^2) (1 - |α|x)^2,$ and $ρ$ is the ratio of the average input power per transmission to the variance of the noise innovation $U_i$. The optimal coding scheme parallels the simple linear signalling scheme by Schalkwijk and Kailath for the additive white Gaussian noise channel -- the transmitter sends a real-valued information-bearing signal at the beginning of communication and subsequently refines the receiver's error by processing the feedback noise signal through a linear stationary first-order autoregressive filter. The resulting error probability of the maximum likelihood decoding decays doubly-exponentially in the duration of the communication. This feedback capacity of the first-order moving average Gaussian channel is very similar in form to the best known achievable rate for the first-order \emph{autoregressive} Gaussian noise channel studied by Butman, Wolfowitz, and Tiernan, although the optimality of the latter is yet to be established.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑