Wireless communication has already changed the way people communicate with each other. With the progress of techniques related wireless communications, many innovative ways of communication have become a reality, thus making it possible for people to communicate with anyone or any device at any time or any place. The most typical examples are the exponentially growing cellular phones and the ubiquitous WiFi coverage. However, what is more exciting is that we continue to see new systems and applications, such as wireless sensor networks, automated highways and factories, driverless cars and unmanned stores, smart homes and appliances, and telemedicine, are emerging from research ideas or laboratories to concrete systems.

That is why wireless communications is an important course for students and engineers specialized in telecommunication engineering.

In this course, we will learn the fundamental of wireless communications. What is wireless communication, the main challenges, how to describe and evaluate the wireless channel,  how the channel affect the performance of a wireless system and how to overcome these problems. We also discuss how a wireless system works. 

This course includes 8 chapters. Chapter 1 gives an overview of the wireless communications, includes the history, the technical challenges, wireless systems and standards. Chapter 2 and 3 discuss the wireless channels. Chapter 2 deals with the large-scale path loss and shadowing, while chapter 3 presents the small-scale fading and statistical multipath channel. In Chapter 4, we discuss the digital modulations and their performance over wireless channels. Chapter 5 to 7 discuss the techniques used in communiqués to overcome the problems caused by the fading. Chapter 5 discusses diversity, channel coding and equalization. In Chapter 6, we discuss spread spectrum systems and spread spectrum with Rake receiver. Chapter 7 deals with multicarrier modulation and multi-antenna systems. In chapter 8, we discuss techniques necessary to build a cellular system, such as duplexing, multiple access, and cellular design fundamentals. We also include a simplified cellular system to ensure the reader understand how a cellular system works. 

The important feature of this course is that we intend to help student to understand wireless communication more quickly and simply. We do not discuss the standard wireless system, which involves more concepts and more factors resulting from the balance of interests in the formation of standards. We try not to use complex mathematical derivations when explaining concepts, but instead provide relatively intuitive and easy-to-understand explanations from a physical sense. This makes it easier for students to understand and combine with actual systems, and learn the wireless system analysis and design.

     无线通信已经改变了人们相互交流的方式。随着无线通信相关技术的不断进步，许多创新的通信方式已经成为现实，使人们可以在任何时间、任何地点与任何人或任何设备进行交流。最典型的例子是呈指数级增长的手机和无处不在的WiFi覆盖。然而，更令人兴奋的是，我们继续看到新的系统和应用，如无线传感器网络、自动化高速公路和工厂、无人驾驶汽车和无人商店、智能家居和电器以及远程医疗，正在从研究思路或实验室转化为具体的系统。

这就是为什么无线通信对于通信工程、信息工程及电子信息类专业的学生和工程师来说是一个重要的课程。

     在这门课程中，我们将学习无线通信的基础知识。什么是无线通信，主要挑战是什么，如何描述和评估无线信道，信道如何影响无线系统的性能以及如何克服这些问题。我们还讨论了无线系统是如何工作的。

    这门课程包括8章。第1章概述了无线通信，包括历史、技术挑战、无线系统和标准。第2章和第3章讨论了无线信道。第2章讨论了大尺度路径损耗和阴影效应，而第3章介绍了小尺度衰落和统计多径信道。在第4章中，我们讨论了数字调制及其在无线信道上的性能。第5至7章讨论了用于克服衰落问题的技术。第5章讨论了分集、信道编码和均衡。在第6章中，我们讨论了扩展频谱系统和具有Rake接收机的扩展频谱。第7章讨论了多载波调制和多天线系统。在第8章中，我们讨论了构建蜂窝系统所需的技术，例如双工、多址和蜂窝设计基本原理。我们还介绍了一个简化的蜂窝系统，以确保读者了解蜂窝系统的工作原理。

      本课程的重要特点是我们旨在帮助学生更快、更简单地理解无线通信。我们不讨论标准的无线系统，这涉及到更多的概念和很多纷繁复杂的因素，这些因素是由于标准制定过程中的利益平衡而产生的。在解释概念时，我们尽量避免使用复杂的数学推导，而是从物理意义上提供相对直观和易于理解的解释。这使得学生更容易理解和与实际系统结合，并学习无线系统分析和设计。

In this course, we will learn the fundamental of wireless communications. What is wireless communication, the main challenges, how to describe and evaluate the wireless channel,  how the channel affect the performance of a wireless system and how to overcome these problems. We will also learrn how a wireless system is structured and  works. 

 在这门课程中，我们将学习无线通信的基础知识。什么是无线通信，主要挑战是什么，如何描述和评估无线信道，信道如何影响无线系统的性能以及如何克服这些问题。我们还会学习无线系统是如何构成和工作的。

Students taking this course are expected to have knowledge of random signal analysis and principles of communication.

选择本课程的同学最好了解随机信号分析和通信原理的相关内容。

BIn Tian, Wireless Communications,  De Gruyter, Science Press, 2024, to be published. 

Andrea Glodsmith, Wireless Communications, Cambridge University Press,2005

Andreas F. Molish , Wireless Communications( 3rd Edition), John Wiley & Sons Ltd. 2023.