principle of communications is the first course to communication systems for undergraduate students, and it aims to uncover how a communication system works and the underlying beautiful theoretical principles. it builds the foundations for students to explore more advanced topics related to communications, ranging from theoretical development to practical implementation, such as wireless communications, wireless networks, internet of things, etc.. lectures are developed to answer the following key question: how to reliably deliver information over an unreliable physical medium?

towards answering this question, we begin with the interface between the cyber and the physical world and explain how to convert from digital to analog and vice versa. next, we introduce a first statistical model, the additive noise channel, that captures the unreliable feature of physical medium, and develop the principle for optimal reconstruction based on statistical decision theory. then, we introduce the key concept of coding in order to achieve reliable communication, together with some concrete examples of codes. these principles are extended to further channel models, namely, wireline (telephone) channel and wireless channel, where additional challenges such as inter-symbol interference (isi) and fading need to be tackled. ofdm is introduced to alleviate isi while diversity techniques are developed to mitigate fading.

textbook:
a. v. oppenheim and r. w. schafer, "discrete-time signal processing," 3rd ed., pearson prentice-hall, 2010.

outline:
1. introduction
2. discrete-time signals and systems (sections 2.0-2.9)
3. the z-transform (sections 3.0-3.8)
4. sampling of continuous-time signals (sections 4.0-4.7)
5. transform analysis of linear time-invariant systems (sections 5.0-5.7)
6. structures for discrete-time systems (sections 6.0-6.6)
7. filter design techniques (sections 7.0-7.6)
8. the discrete fourier transform (sections 8.0-8.7)
9. computation of the discrete fourier transform (sections 9.0-9.3)

grading policy:
midterm i: 30%; midterm ii: 30%; final: 40%; two bonus quizs: 10%

the primary goal of this course is to provide the basic tools and knowledge needed to design optical systems. at the end of the course, students will be able to take system requirements, select possible components and approaches, create candidate designs and analyze and optimize their performance.