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arXiv 1908.08407cs.ITmath.IT
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通过共享随机性进行协调

Coordination Through Shared Randomness

Gowtham R. Kurri, Vinod M. Prabhakaran, Anand D. Sarwate

摘要:

我们研究了一个分布式采样问题,一组处理器要输出(近似)独立和相同分布的样本从一个联合分布的帮助下,从一个协调员的共同消息。每个处理器都可以访问来自一组独立的“共享”随机性源的源子集。我们考虑两种情况-在“全知的协调设置”,协调员可以访问所有这些共享随机性的来源,而在“健忘的协调设置”,它可以访问没有。所有处理器和协调器可以私下随机化。在全知的协调器设置,当在处理器的子集是不相交的(单独共享的随机模型),我们的特点所需的通信速率从协调器的处理器通过多播链路。对于两个处理器的情况,最佳速率匹配Gastpar和Sula(2019)提出的放松Wyner公共信息的特殊情况,从而为后者提供了操作意义。我们还给出了一个上限的通信速率的“随机性的额头”模型,每个处理器观察所有,但一个源的随机性,我们给出了一个可实现的策略,处理器可以访问任意子集的随机性源的一般情况下。此外,我们考虑一个更一般的模型,其中的处理器观察组件的相关源(与协调员观察所有的组件),其中我们的通信速率的特征时,所有的处理器希望输出相同的随机序列。在不经意的协调设置,我们完全特征之间的通信和共享的随机性率的一般情况下,处理器可以访问任意子集的随机性源之间的权衡区域。

英文摘要:

We study a distributed sampling problem where a set of processors want to output (approximately) independent and identically distributed samples from a joint distribution with the help of a common message from a coordinator. Each processor has access to a subset of sources from a set of independent sources of "shared" randomness. We consider two cases -- in the "omniscient coordinator setting", the coordinator has access to all these sources of shared randomness, while in the "oblivious coordinator setting", it has access to none. All processors and the coordinator may privately randomize. In the omniscient coordinator setting, when the subsets at the processors are disjoint (individually shared randomness model), we characterize the rate of communication required from the coordinator to the processors over a multicast link. For the two-processor case, the optimal rate matches a special case of relaxed Wyner's common information proposed by Gastpar and Sula (2019), thereby providing an operational meaning to the latter. We also give an upper bound on the communication rate for the "randomness-on-the-forehead" model where each processor observes all but one source of randomness and we give an achievable strategy for the general case where the processors have access to arbitrary subsets of sources of randomness. Also, we consider a more general model where the processors observe components of correlated sources (with the coordinator observing all the components), where we characterize the communication rate when all the processors wish to output the same random sequence. In the oblivious coordinator setting, we completely characterize the trade-off region between the communication and shared randomness rates for the general case where the processors have access to arbitrary subsets of sources of randomness.

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。

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