In this work, we consider reliable transmissions for grant-free random access (GFRA) when machine-type communication (MTC) devices have a message of multiple short data packets to transmit. An existing approach is based on ${K}$ -repetition for reliable transmissions. In order to improve the reliability, a random network coding based scheme is proposed, where each device in GFRA employs random network coding to transmit packets that are linear combinations of its original packets. To shed light on the performance behaviors of the conventional ${K}$ -repetition and proposed schemes, we derive their error probabilities and provide an indicative analysis. Simulation results validate our derivations and show that the proposed scheme by exploiting random network coding can perform significantly better than conventional ${K}$ -repetition one.

中文翻译：

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无授权随机访问中 K 重复的网络编码


在这项工作中，我们考虑当机器类型通信（MTC）设备有多个短数据包的消息要传输时，无授权随机接入（GFRA）的可靠传输。现有方法基于 ${K}$ 重复来实现可靠传输。为了提高可靠性，提出了一种基于随机网络编码的方案，其中GFRA中的每个设备都采用随机网络编码来传输其原始数据包的线性组合的数据包。为了阐明传统 ${K}$ 重复和建议方案的性能行为，我们推导了它们的错误概率并提供了指示性分析。仿真结果验证了我们的推导，并表明所提出的利用随机网络编码的方案的性能明显优于传统的 ${K}$ 重复方案。