Information Processing and Telecommunications Center, Universidad Politécnica de Madrid, 28040 Madrid, Spain.
ETSI de Telecomunicación, Universidad Politécnica de Madrid, 28040 Madrid, Spain.
Sensors (Basel). 2021 Feb 16;21(4):1372. doi: 10.3390/s21041372.
Millimeter-Wave (mmWave) bands are receiving enormous attention in 5G mobile communications, due to the capability to provide a multi-gigabit transmission rate. In this paper, a two-hop architecture for 5G communications with the capacity to support high end-to-end performance due to the use of Relay Nodes (RNs) in mmWave-bands is presented. One of the novelties of the paper is the implementation of Amplify-and-Forward (A&F) and Decode-and-Forward (D&F) RNs along with a mmWave-band transceiver chain (Tx/Rx). In addition, two approaches for channel estimation were implemented at the D&F RN for decoding the backhaul link. One of them assumes complete knowledge of the channel (PCE), and the other one performs the channel estimation through Least Square (LS) estimator. A large number of simulations, using MATLABTM and SimulinkTM software, were performed to verify the potential benefits of the proposal two-hop 5G architecture in an outdoor-to-indoor scenario. The main novelty in performing these simulations is the use of signals with 5G features, as DL-SCH transport channel coding, PDSCH generation, and SS Burst generation, which is another of the main contributions of the paper. On the other hand, mmWave transmitter and receiver chains were designed and implemented with off-the shelf components. The simulations show that the two-hop network substantially improves the Key Performance Indicators (KPIs), Bit Error Rate (BER), and Throughput, in the communications between the logical 5G Radio Node (gNodeB), and the New Radio User Equipment (NR-UE). For example, a throughput improvement of 22 Mbps is obtained when a 4 × 4 × 2 MIMO D&F with LS architecture is used versus a SISO D&F with PCE architecture for Signal-to-Noise Ratio (SNR) = 20 dB and 64-QAM signal. This improvement reaches 96 Mbps if a 256-QAM signal is considered. The improvement in BER is 11 dB and 10.5 dB, respectively, for both cases. This work also shows that the obtained results with D&F RNs are better than with A&F RNs. For example, an improvement of 17 Mbps in the use of SISO D&F with LS vs. SISO A&F, for the 64-QAM signal is obtained. Besides, this paper constitutes a first step to the implementation of a mmWave MIMO 5G cooperative network platform.
毫米波（mmWave）频段在 5G 移动通信中受到极大关注，因为它能够提供多吉比特的传输速率。本文提出了一种在毫米波频段使用中继节点（RN）的 5G 通信的两跳架构，由于使用了中继节点（RN），因此能够支持高的端到端性能。本文的一个新颖之处在于实现了 Amplify-and-Forward (A&F) 和 Decode-and-Forward (D&F) RN 以及毫米波收发器链（Tx/Rx）。此外，在 D&F RN 中实现了两种用于解码回程链路的信道估计方法。其中一种方法假设对信道具有完全了解（PCE），而另一种方法则通过最小二乘（LS）估计器进行信道估计。使用 MATLABTM 和 SimulinkTM 软件进行了大量的仿真，以验证在户外到室内场景中提出的两跳 5G 架构的潜在优势。在执行这些仿真时的主要新颖之处在于使用具有 5G 特征的信号，例如 DL-SCH 传输信道编码、PDSCH 生成和 SS 突发生成，这是本文的另一个主要贡献。另一方面，使用现成的组件设计和实现了毫米波发射机和接收机链。仿真结果表明，在逻辑 5G 无线电节点（gNodeB）和新无线电用户设备（NR-UE）之间的通信中，两跳网络大大提高了关键性能指标（KPI）、误码率（BER）和吞吐量。例如，当使用具有 LS 架构的 4×4×2 MIMO D&F 与 SNR=20dB 和 64-QAM 信号的具有 PCE 架构的 SISO D&F 相比时，吞吐量提高了 22Mbps。如果考虑使用 256-QAM 信号，则可提高 96Mbps。BER 分别提高了 11dB 和 10.5dB。这项工作还表明，与 A&F RN 相比，D&F RN 的结果更好。例如，在使用具有 LS 的 SISO D&F 与 SISO A&F 相比时，对于 64-QAM 信号，获得了 17Mbps 的改进。此外，本文构成了实现毫米波 MIMO 5G 协作网络平台的第一步。
