This paper investigates adaptive streaming codes over a three-node relayed network. In this setting, a source transmits a sequence of message packets through a relay under a delay constraint of $T$ time slots per packet. The source-to-relay and relay-to-destination links are unreliable and introduce a maximum of $N_1$ and $N_2$ packet erasures respectively. Recent work has proposed adaptive (time variant) and nonadaptive (time invariant) code constructions for this setting and has shown that adaptive codes can achieve higher rates. However, the adaptive construction deals with many possibilities, leading to an impractical code with very large block lengths. In this work, we propose a simplified adaptive code construction which greatly improves the practicality of the code, with only a small cost to the achievable rates. We analyze the construction in terms of the achievable rates and field size requirements, and perform numerical simulations over statistical channels to estimate packet loss probabilities.

翻译：本文研究在三节点中继网络上运行的自适应流编码。在该场景下，信源通过中继在每数据包$T$个时隙的延迟约束下传输一系列消息数据包。信源到中继链路以及中继到目的链路不可靠，分别引入最多$N_1$和$N_2$个数据包擦除。近期工作提出了针对该场景的自适应（时变）与非自适应（时不变）编码构造，并证明了自适应编码可实现更高码率。然而，自适应构造需处理大量可能性，导致码字块长极大且不切实际。本文提出一种简化的自适应编码构造方案，在仅牺牲少量可实现的码率条件下显著提升编码实用性。我们从可实现码率和域大小需求角度分析该构造，并通过统计信道数值仿真估计数据包丢失概率。