Irregular repetition slotted aloha (IRSA) is a massive random access protocol in which users transmit several replicas of their packet over a frame to a base station. Existing studies have analyzed IRSA in the single-cell (SC) setup, which does not extend to the more practically relevant multi-cell (MC) setup due to the inter-cell interference. In this work, we analyze MC IRSA, accounting for pilot contamination and multiuser interference. Via numerical simulations, we illustrate that, in practical settings, MC IRSA can have a drastic loss of throughput, up to $70\%$, compared to SC IRSA. Further, MC IRSA requires a significantly higher training length (about 4-5x compared to SC IRSA), in order to support the same user density and achieve the same throughput. We also provide insights into the impact of the pilot length, number of antennas, and signal to noise ratio on the performance of MC IRSA.

翻译：经常重复插槽的光圈(IRSA)是一个巨大的随机访问协议,用户在其中向一个基地站传送其包的多个复制品,现有研究分析了单细胞(SC)装置中的IRSA,由于细胞间干扰,该装置不延伸至更切合实际的多细胞(MC)装置。在这项工作中,我们分析MC IRSA,其中考虑到试点污染和多用户干扰。通过数字模拟,我们说明MC IRSA在实际环境中的吞吐量可能急剧损失,与SC IRSA相比高达70美元。此外,MC IRSA需要大大延长培训时间(与SC IRSA相比约为4-5x),以便支持同样的用户密度并实现同样的吞吐量。我们还深入了解试验长度、天线数目和噪音对MC IRSA性能的信号的影响。