摘 要
毫米波通信具有丰富的频谱资源，被认为是第五代（5G）移动通信系统实现高达20Gbps峰值数据速率的关键技术之一。然而，毫米波通信具有高度的方向性传输，极易受到障碍物遮挡，路损大，且有效通信距离短，这对移动覆盖是一大挑战。近年来所提出的智能反射表面通过调控电磁波传播可以有效地改善通信质量并扩展通信距离，为解决毫米波通信覆盖范围小的这个关键问题提供了新思路。此外，传统的中继技术也是实现毫米波通信覆盖范围扩展的有效方法之一。因此，本文研究面向B5G的融合智能反射表面和中继的毫米波通信技术方案和性能具有重要的意义。
首先，本文介绍了毫米波通信和智能反射表面的基本原理。毫米波（mmWave）通信被认为是未来蜂窝网络的一项有前途的技术，因为它具有较大的可用带宽和提供每秒千兆比特通信数据率的潜力。利用大智能反射表面对毫米波系统至关重要，因为与低于6GHz的微波信号相比，毫米波信号的自由空间路径损耗要高得多。智能反射表面可以帮助形成定向波束，以补偿毫米波信号产生的严重路径损耗。
其次，本文考虑毫米波通信网络中部署智能反射表面的场景，研究了基于智能反射表面的毫米波通信，高指向性使毫米波通信容易受到阻断事件的影响，而这种情况在室内和密集的城市环境中可能很常见。智能反射面（IRS）作为一种潜在的低成本解决方案出现，可以重塑无线传播环境，提高频谱效率。并与传统的基于中继的毫米波通信进行了性能比较得到了IRS部署规模对于其性能的影响关系。。
再次，本文考虑智能反射表面和中继节点共存的场景，研究了基于混合智能反射表面和中继的毫米通信，提出了一种新的基于毫米波（mmWave）的智能反射面（IRS）和未来无线网络的中继系统，其中智能反射面（IRS）被用来支持从基站（BS）到用户设备（UE）的下行数据传输。仿真结果表明，在辐射功率和反射元件数量有限的实际情况下，通过使用简单的解码和转发（DF）中继，可以显著提高IRS支持系统的性能。在不同的信道环境下，为所提出的方案推导出传输容量的严格上界，并证明与蒙特卡洛模拟密切相关。
关键词：智能反射表面；电磁波调控；中继；译码转发
毫米波通信具有丰富的频谱资源，被认为是第五代（5G）移动通信系统实现高达20Gbps峰值数据速率的关键技术之一。然而，毫米波通信具有高度的方向性传输，极易受到障碍物遮挡，路损大，且有效通信距离短，这对移动覆盖是一大挑战。近年来所提出的智能反射表面通过调控电磁波传播可以有效地改善通信质量并扩展通信距离，为解决毫米波通信覆盖范围小的这个关键问题提供了新思路。此外，传统的中继技术也是实现毫米波通信覆盖范围扩展的有效方法之一。因此，本文研究面向B5G的融合智能反射表面和中继的毫米波通信技术方案和性能具有重要的意义。
首先，本文介绍了毫米波通信和智能反射表面的基本原理。毫米波（mmWave）通信被认为是未来蜂窝网络的一项有前途的技术，因为它具有较大的可用带宽和提供每秒千兆比特通信数据率的潜力。利用大智能反射表面对毫米波系统至关重要，因为与低于6GHz的微波信号相比，毫米波信号的自由空间路径损耗要高得多。智能反射表面可以帮助形成定向波束，以补偿毫米波信号产生的严重路径损耗。
其次，本文考虑毫米波通信网络中部署智能反射表面的场景，研究了基于智能反射表面的毫米波通信，高指向性使毫米波通信容易受到阻断事件的影响，而这种情况在室内和密集的城市环境中可能很常见。智能反射面（IRS）作为一种潜在的低成本解决方案出现，可以重塑无线传播环境，提高频谱效率。并与传统的基于中继的毫米波通信进行了性能比较得到了IRS部署规模对于其性能的影响关系。。
再次，本文考虑智能反射表面和中继节点共存的场景，研究了基于混合智能反射表面和中继的毫米通信，提出了一种新的基于毫米波（mmWave）的智能反射面（IRS）和未来无线网络的中继系统，其中智能反射面（IRS）被用来支持从基站（BS）到用户设备（UE）的下行数据传输。仿真结果表明，在辐射功率和反射元件数量有限的实际情况下，通过使用简单的解码和转发（DF）中继，可以显著提高IRS支持系统的性能。在不同的信道环境下，为所提出的方案推导出传输容量的严格上界，并证明与蒙特卡洛模拟密切相关。
关键词：智能反射表面；电磁波调控；中继；译码转发
Abstract
Millimetre wave (mmWave)communication has abundant spectrum resources and is considered one of the key technologies for achieving peak data rates of up to 20 Gbps in fifth generation (5G) mobile communication systems. However, mmWave communication is highly directional in transmission, highly susceptible to obstacle occlusion, high road loss and short effective communication distance, which is a major challenge for mobile coverage. Intelligent reflective surfaces proposed in recent years can effectively improve communication quality and extend communication distances by modulating electromagnetic wave propagation, providing a new idea to solve this key problem of small mmWave communication coverage. In addition, traditional relaying techniques are also one of the effective ways to achieve the extended coverage of mmWave communications. Therefore, it is of great importance to study the solution and performance of mmWave communication technology that incorporates intelligent reflective surfaces and relaying for B5G in this paper.
First, this paper introduces the basic principles of mmWave communication and smart reflective surfaces. MmWave communication is considered a promising technology for future cellular networks because of its large available bandwidth and potential to deliver gigabits per second communication data rates. The use of large smart reflective surfaces is essential for mmWave systems as the free space path loss of mmWave signals is much higher compared to microwave signals below 6 GHz. Smart reflective surfaces can help form directional beams to compensate for the severe path loss incurred by mmWave signals.
Secondly, this paper investigates mmWave communications based on smart reflective surfaces by considering scenarios where smart reflective surfaces are deployed in mmWave communication networks. The high directivity makes mmWave communications vulnerable to blocking events, which can be common in indoor and dense urban environments. Intelligent Reflective Surfaces (IRS) emerge as a potential low-cost solution that can reshape the wireless propagation environment and improve spectral efficiency. A performance comparison with conventional relay-based mmWave communications is also obtained to determine the relationship between the size of IRS deployments on their performance.
Again, this paper considers the scenario of coexistence of smart reflective surfaces and relay nodes and investigates mmWave communications based on hybrid smart reflective surfaces and relays, proposing a new mmWave -based smart reflective surface
(IRS) and relay system for future wireless networks, where the smart reflective surface (IRS) is used to support downlink data transmission from the base station (BS) to the user equipment (UE) . Simulation results show that the performance of IRS-supported systems can be significantly improved by using simple decode-and-forward (DF) relays in practical situations where the radiated power and number of reflective elements are limited. Strict upper bounds on the transmission capacity are derived for the proposed scheme in different channel environments and are shown to be closely related to Monte Carlo simulations.
Keywords: Intelligent reflective surfaces; Electromagnetic wave modulation; Relaying; Decode-and-forward
Millimetre wave (mmWave)communication has abundant spectrum resources and is considered one of the key technologies for achieving peak data rates of up to 20 Gbps in fifth generation (5G) mobile communication systems. However, mmWave communication is highly directional in transmission, highly susceptible to obstacle occlusion, high road loss and short effective communication distance, which is a major challenge for mobile coverage. Intelligent reflective surfaces proposed in recent years can effectively improve communication quality and extend communication distances by modulating electromagnetic wave propagation, providing a new idea to solve this key problem of small mmWave communication coverage. In addition, traditional relaying techniques are also one of the effective ways to achieve the extended coverage of mmWave communications. Therefore, it is of great importance to study the solution and performance of mmWave communication technology that incorporates intelligent reflective surfaces and relaying for B5G in this paper.
First, this paper introduces the basic principles of mmWave communication and smart reflective surfaces. MmWave communication is considered a promising technology for future cellular networks because of its large available bandwidth and potential to deliver gigabits per second communication data rates. The use of large smart reflective surfaces is essential for mmWave systems as the free space path loss of mmWave signals is much higher compared to microwave signals below 6 GHz. Smart reflective surfaces can help form directional beams to compensate for the severe path loss incurred by mmWave signals.
Secondly, this paper investigates mmWave communications based on smart reflective surfaces by considering scenarios where smart reflective surfaces are deployed in mmWave communication networks. The high directivity makes mmWave communications vulnerable to blocking events, which can be common in indoor and dense urban environments. Intelligent Reflective Surfaces (IRS) emerge as a potential low-cost solution that can reshape the wireless propagation environment and improve spectral efficiency. A performance comparison with conventional relay-based mmWave communications is also obtained to determine the relationship between the size of IRS deployments on their performance.
Again, this paper considers the scenario of coexistence of smart reflective surfaces and relay nodes and investigates mmWave communications based on hybrid smart reflective surfaces and relays, proposing a new mmWave -based smart reflective surface
(IRS) and relay system for future wireless networks, where the smart reflective surface (IRS) is used to support downlink data transmission from the base station (BS) to the user equipment (UE) . Simulation results show that the performance of IRS-supported systems can be significantly improved by using simple decode-and-forward (DF) relays in practical situations where the radiated power and number of reflective elements are limited. Strict upper bounds on the transmission capacity are derived for the proposed scheme in different channel environments and are shown to be closely related to Monte Carlo simulations.
Keywords: Intelligent reflective surfaces; Electromagnetic wave modulation; Relaying; Decode-and-forward
目 录
第1章 绪 论
1.1背景与意义
1.2国内外发展（应用）现状
1.3论文所做工作及思路
1.4论文章节安排
第2章 毫米波通信与智能反射表面技术的基本原理
2.1毫米波通信技术
2.1.1毫米波信道模型
2.1.2毫米波MIMO波束赋形
2.2 系智能反射表面技术
2.2.1 IRS智能反射表面综述
2.2.2反馈信道简述
2.2.3无线信道的传输条件简述
2.3 基于智能反射表面的毫米波通信系统模型
2.4 名词解释
2.5 本章小结
第3章 基于多IRS的无线通信性能分析与仿真
3.1 引言
3.2 基于多IRS的两跳无线通信性能分析与仿真
3.2.1基于IRS的通信系统模型
3.2.2基于中继的通信系统模型
3.3 基于多IRS的多跳无线通信性能分析与仿真
3.3.1速率约束下的发射功率最小化
3.3.2速率约束下的总功耗最小化
3.4仿真结果与分析
3.4本章小结
第4章 IRS与中继复合模型的性能与仿真
4.1 引言
4.2 混合IRS和半双工中继的两跳无线通信性能分析与仿真
4.2混合IRS和半双工中继的两跳无线通信性能分析与仿真
4.2.1瑞利衰落信道的可实现速率的严格上限值
4.2.2混合瑞利和瑞森衰落信道下的可实现速率的严格上限值
4.2.3最佳的功率分配和传输模式选择
4.2.4仿真结果
4.3 基于多IRS的多跳无线通信性能分析与仿真
4.4 本章小结
结 论
致 谢
参考文献
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