论文标题
关于广播频道的延迟分析,关于Erdős和Rényi的旧问题
On an Old Question of Erdős and Rényi Arising in the Delay Analysis of Broadcast Channels
论文作者
论文摘要
考虑使用$ N $用户的广播频道,其中不同的用户会收到不同的消息,并假设每个用户必须接收$ M $数据包。 Sharif and Hassibi(2006-7)\ Cite {Sh},\ Cite {S-H}引入的一定数量是(\ emph {packet})\ emph {delays} $ d_ {m d_ {m,n} $,即保证所有用户都会收到$ m $ packets。 For the case of a \emph{homogeneous} network, where in each channel use the transmitter chooses a user at random, i.e. with probability $1/n$, and sends him$/$her a packet, the same quantity $D_{m,n}$ had already appeared in the \emph{coupon collector} context, in the works of Newman and Shepp (1960) \cite{N-S} and Erdős和Rényi(1961)\ cite {e-r}的作品。 与延迟$ d_ {m,n} $有关的无线通信特别感兴趣的问题是将其行为确定为$ n $和$ m $生长大。关于这个问题,sharif和hassibi \ cite {sh},\ cite {s-h}设法计算了平均值$ \ mathbb {e}的渐近学$ρ> 1 $。值得注意的是,Erdős和Rényi\ cite {e-r}也提出了一个问题,即确定$ d_ {m,n} $的渐近配置文件的大型$ m $和$ n $(1961年)。在1970年代,Ivchenko \ cite \ cite {i1}和\ cite {i2}确定了$ d_ {m,n} $和$ n $的$ d_ {m,n} $。 在本文中,我们确定了大型$ m $和$ n $的$ d_ {m,n} $矩的渐近学。我们还通过一种方法与Ivchenko使用的方法不同,在“超临界情况”中得出了其限制分布,其中$ m $生长的速度快于$ \ ln n $,而在“关键情况” $ M \ simβ\ ln n $中。
Consider a broadcast channel with $n$ users, where different users receive different messages, and suppose that each user has to receive $m$ packets. A quantity of interest here, introduced by Sharif and Hassibi (2006-7) \cite{Sh}, \cite{S-H}, is the (\emph{packet}) \emph{delay} $D_{m,n}$, namely the number of channel uses required to guarantee that all users will receive $m$ packets. For the case of a \emph{homogeneous} network, where in each channel use the transmitter chooses a user at random, i.e. with probability $1/n$, and sends him$/$her a packet, the same quantity $D_{m,n}$ had already appeared in the \emph{coupon collector} context, in the works of Newman and Shepp (1960) \cite{N-S} and of Erdős and Rényi (1961) \cite{E-R}. A problem of particular interest in wireless communications, related to the delay $D_{m,n}$, is to determine its behavior as $n$ and $m$ grow large. Regarding this problem, Sharif and Hassibi \cite{Sh}, \cite{S-H} managed to calculated the asymptotics of the mean value $\mathbb{E}[D_{m,n}]$, as $n \to \infty$, for the cases (a) $m = \ln n$ and (b) $m = (\ln n)^ρ$, $ρ> 1$. It is remarkable that Erdős and Rényi \cite{E-R} had, also, raised the question of the determination of the asymptotic profile of $D_{m,n}$ for large $m$ and $n$ (in 1961). And in the 1970's the limiting distribution of $D_{m,n}$ for large $m$ and $n$ was determined (in great generality) by Ivchenko \cite{I1} and \cite{I2}. In this article we determine the asymptotics of the moments of $D_{m,n}$ for large $m$ and $n$. We also derive its limiting distribution in the "supercritical case" where $m$ grows faster than $\ln n$ and in the "critical case" $m \sim β\ln n$, by an approach which is different from the one used by Ivchenko.