论文标题
在线估计和适应随机访问，并连续取消
Online Estimation and Adaptation for Random Access with Successive Interference Cancellation
论文作者
论文摘要
本文提出了一种自适应传输算法，用于支撑连续干扰取消（SIC）的插入随机访问系统（AP）。当多个用户在插槽中同时发送数据包（由于SIC技术），AP能够通过SIC解析过程（SRP）来解码它们，该过程可能占据多个随之而来的插槽。尽管这样的SRP可能有可能改善系统吞吐量，但如何在实践系统中充分利用此功能仍然值得怀疑。特别是，争夺通道的活动用户数量随着时间而变化，这使算法设计变得复杂。通过充分利用SIC的电位，提出的算法旨在最大化系统吞吐量并最大程度地减少访问延迟。为此，引入了在线估计，以实时估算活跃用户的数量，并相应地控制其传输。结果表明，在实际假设下，提出的算法的吞吐量最高可达0.693个数据包/插槽，这是实现Yu-Giannakis证明的吞吐量极限的第一个结果。进一步表明，当SIC功能受到两个限制时，仍然可以实现0.559个数据包/插槽（80.6 $ \％$ $ \％$）的系统吞吐量（80.6 $ \％$）。
This paper proposes an adaptive transmission algorithm for slotted random access systems supporting the successive interference cancellation (SIC) at the access point (AP). When multiple users transmit packets simultaneously in a slot, owing to the SIC technique, the AP is able to decode them through SIC resolve procedures (SRPs), which may occupy multiple consequent slots. While such an SRP could potentially improve the system throughput, how to fully exploit this capability in practical systems is still questionable. In particular, the number of active users contending for the channel varies over time which complicates the algorithm design. By fully exploiting the potential of SIC, the proposed algorithm is designed to maximize the system throughput and minimize the access delay. For this purpose, an online estimation is introduced to estimate the number of active users in real-time and controls their transmissions accordingly. It is shown that the throughput of the proposed algorithm can reach up to 0.693 packets/slot under practical assumptions, which is the first result achieving the throughput limit proved by Yu-Giannakis. It is further shown that the system throughput of 0.559 packets/slot (80.6$\%$ of the throughput limit) is still achievable when the SIC capability is restricted by two.
