Fluctuating two-ray (FTR) channel model was shown to effectively characterize millimeter wave (mmWave) communication channels. In this article, we adopt FTR to investigate amplify-and-Forward (AF) mmWave relaying system. Two communications scenarios are considered corresponding to the presence and absence of a direct link between the transmitter and receiver. Outage probability and symbol error rate (SER) are then analytically obtained as performance metrics. The results are further compared with the corresponding metrics obtained based on conventional channel models including Nakagami- ${m}$ and two-wave with diffuse power (TWDP). Especially, for the high-SNR regime, our analyses indicate that performance evaluations based on the conventional models significantly deviate from that of based on the FTR model. Our results provide quantitative insights on the importance of model selection in design and performance evaluations of relay-based mmWave systems. Moreover, for the high-SNR regime, we carry out asymptotic analysis and obtain a low-complexity expression for the achieved AF relaying gain. Such an expression provides a quantitative measure on whether or not AF relaying outperforms no-relaying in a given setting. Extensive numerical and simulation results are provided to confirm the accuracy of the analysis and investigate system performance in different settings.

中文翻译：

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波动两射线通道上最大比组合的放大转发中继：非渐近和渐近性能分析

显示波动两射线 (FTR) 信道模型可有效表征毫米波 (mmWave) 通信信道。在本文中，我们采用 FTR 来研究放大转发 (AF) 毫米波中继系统。两种通信场景被认为对应于发射机和接收机之间直接链路的存在和不存在。然后通过分析获得中断概率和符号错误率 (SER) 作为性能指标。结果与基于包括 Nakagami-${m}$ 和具有扩散功率的两波 (TWDP) 在内的传统信道模型获得的相应指标进行了进一步比较。特别是，对于高 SNR 机制，我们的分析表明，基于传统模型的性能评估与基于 FTR 模型的性能评估显着不同。我们的结果提供了关于模型选择在基于继电器的毫米波系统的设计和性能评估中的重要性的定量见解。此外，对于高 SNR 机制，我们进行渐近分析并获得实现的 AF 中继增益的低复杂度表达式。这样的表达式提供了关于 AF 中继在给定设置中是否优于无中继的定量度量。提供了广泛的数值和模拟结果，以确认分析的准确性并研究不同设置下的系统性能。这样的表达式提供了在给定设置中 AF 中继是否优于无中继的定量度量。提供了广泛的数值和模拟结果，以确认分析的准确性并研究不同设置下的系统性能。这样的表达式提供了关于 AF 中继在给定设置中是否优于无中继的定量度量。提供了广泛的数值和模拟结果，以确认分析的准确性并研究不同设置下的系统性能。