pass: quangtung1123
Friday, October 14, 2011
Giao tiếp AVR với máy tính qua cổng COM
M xin được giới thiệu ứng dụng của AVR thông qua giao tiếp qua cổng COM với sự điều khiển của phần mềm Visual Basic.
Wednesday, September 14, 2011
Mô phỏng đèn giao thông
Giao thông là một vấn đề vô cùng phức tạp, mà vẫn chưa có cách giải quyết triệt để. Hôm nay, mình xin giới thiệu với các bạn mạch mô phỏng đèn giao thông sử dụng vi điều khiển AVR. Thực tế thì đối với đèn giao thông thì không cần dùng đến vi điểu khiển chúng ta cũng có thể xây dựng được mạch, nhưng ở đay tôi dùng vi điều khiển để khai thác một phần chức năng của vi điều khiển và có thể ứng dụng vi điều khiển để chế tạo ra một mạch đèn giao thông thông minh trong tương lai. Tuy mạch còn nhiều thiếu sót và chưa tối ưu nên mong các bạn tham khảo và cho ý kiến và nêu ra ý tưởng để giúp tôi có thể hoàn thiện mạch giao thông thông minh, có thể ứng dụng trong thực tế. Xin cảm ơn rất nhiều!!!
Mạch mô phỏng: Download
pass: quangtung1123
Mạch mô phỏng: Download
pass: quangtung1123
Bài giảng Thong tin số của TS. Trịnh Anh Dũng
Chương 1: Giới thiệu chung
1.1 Quá
trình truyền tin
1.2 Truyền tin số
1.3 Kênh
truyền tin
1.4 Tín
hiệu băng cơ sở và tín hiệu băng thông dải
1.5 Chú
thích lịch sử
Chương 2: Truyền tin số qua kênh băng cơ sở
2.1 Tín
hiệu PAM rờ rạc
2.2 Phổ
công suất của tín hiệu PAM rời rạc
2.3 Giao
thoa giữa các ký hiệu (ISI)
2.4 Tiêu
chuẩn Nyquistcho truyền tin không méo
Thursday, May 26, 2011
Friday, April 15, 2011
Digital Communications 4th editions
Digital Communications 4th editions
1
Introduction
1-1 Elements of
a Digital Communication System
1-2 Communication
Channels ' and Their Characteristics
1-3
Mathematical Models for Communication Channels
1-4 A
Historical Perspective in tbe Development of Digital Communications
1-5 Overview of
the Book
1-6
Bibliograpbical Noles and References
2
Probability and Stochastic Processes
2-1 Probability
2-1-1 Random
Variables, Probability Distributions.
and Probability
Densities
2-1-2 Functions
of Random Variables
2-1-3
Statistical Averages of Random Variables
2-1-4 Some
Useful Probability Distributions
2-1-5 Upper bounds
on the
Tail
Probability
2-1-6 Sums of
Random Variables and the Central limit
2-2 Stocbastic
Processes 62
2-2-1
Statistical Averages 64
2-2-2 Power Density
Spectrum 67
2-2-3 Response of a linear
Time-Invariant System to a Random Input Signal 68
2-2-4 Sampling
Theorem for Band-Limited Stochastic Processes 72
2-2-5
Discrete-Tune Stochastic Signals and Systems 74
2-2-6
Cyclostationary Processes
75
2-3
Bibliograpbical Notes and
References
77
Problems 77
3 Source Coding 82
3-1 Mathematical
Models for Information 82
3-2 A
Logarithmic Measure of Information 84
3-2-1 Average
Mutual Information and Entropy 87
3-2-2
Information Measures for Continuous Random Variables 91
3-3 Coding for
Discrete Sources 93
3-3-1 Coding for
Discrete Memoryless Sources 94
3-3-2 Discrete
Stationary Sources 103
3-3-3 The
Lempel-Ziv Algorithm 106
3-4 Coding for
Analog Sources-Optimum Quantization 108
3-4-1
Rate-Distortion Function 108
3-4-2 Scalar
Quantization 113
3-4-3 Vector
Quantization 118
3-5 Coding
Techniques for Analog Sources 125
3-5-1 Temporal
Waveform Coding 125
3-5-2 Spectral
Waveform Coding 136
3-5-3
Model-Based Source Coding 138
3-6
Bibliographical Notes and Refmmces 144
Problems 144
4 Characterization
of Communication Signals
and Systems 152
4-1
Representation of Bandpass Signals and Systems 152
4-1-1
Representation of Bandpass Signals 153
4-1-2
Representation of Unear Bandpass Systems 157
4-1-3 Response
of a Bandpass System to a Bandpass Signal 157
4-1-4
Representation of Bandpass Stationary Stochastic Processes 159
4-2 Signal Space
Representation 163
4-2-1 Vector
Space Concepts 163
4-2-2 Signal
Space Concepts 165
4-2-3 Orthogonal
Expansions of Signals 165
4-3 Represen
tation of Digitally Modulated Signals 173
4-3-1 Memoryless
Modulation Methods 174
4-3-2 Linear
Modulation With Memory 186
4-3-3 Nonlinear
Modulation Metbods with Memory 190
4-4 Spectral
Cbaracteristics of Digitally Modulated Signals 203
4-4-1 Power
Specua of Linearly Modulated Si&nals 204
4-4-2 Power
Spectra of CPFSK and CPM Signals 209
4-4-3 Power
Spe,<,ra of Modulated Signals with Memory 220
4-5
Bibliograpbical Notes and Referen~ 223
Problems 224
5 Optimum
Receivers for the Additive White Gaussian Noise Channel 233
5-1 Optimum
Receiver for Signals (Jorrupted by A WGN 233
5-1-1
Correlation Demodulator 234
5-1-2
Matched-Filter Demodulator 238
5-1-3 The Optimum
Detector 244
5-1-4 The
Maximum-Likelihood Sequence Detector 249
5-1-5 A Symbol-by-Symbol
MAP Detector for Signals with Memory 254
5-2 Performance of
the Optimum Receiver for Memoryless Modulation 257
5-2-1 Probability of
Error for Binary Modulation 257
5-2-2 Probability of
Error for M-ary Orthogonal Signals 260
5-2-3 Probability of
Error for M
-ary
Biorthogonal Signals 264
5-2-4 Probability of
Error for Simplex Signals 266
5-2-5 Probability of
Error for M-ary Binary-Coded Signals 266
Wednesday, April 13, 2011
Simulation and Software Radio for Mobile Communications.Scanned_MAZ
Preface
Knowledge, the object of knowledge, and the knower are the
three factors that motivate the action; the senses, the work, and the doer are
the three constituents of action.
- The Bhagvad Gita (I 8. 18)
From September 1996 to August 1997, we worked together at the
Delft Univetsity of Technology, The Netherlands, in order to realize future
wireless personal multimedia communications (WPMC). During our joint research period,
research and development were done on higher layers such as the media access
control (MAC) layer and the physical layer, and many researchers came from
Europe, Asia, the United States, and The Netherlands to work with us. We also
starred new projects and established a joint cooperation with several research
institutes, companies, and universities. Once a project is defined, many new
researchers are allocated. Among the researchers, some newcomers arc
occasionally involved. Moreover, most projects are time-limited. In this
situation, the answer to the question of how newcomers prepare to evaluate the
target is one of key issues to success in the time-limited project. We
considered the answer carefully.
Thursday, March 17, 2011
Electromagnetic Waves and Antennas
Preface
This text provides a broad and applications-oriented introduction to electromagnetic waves and antennas. Current interest in these areas is driven by the growth in wireless and fiber-optic communications, information technology, and materials science. Communications, antenna, radar, and microwave engineers must deal with the generation, transmission, and reception of electromagnetic waves. Device engineers working
This text provides a broad and applications-oriented introduction to electromagnetic waves and antennas. Current interest in these areas is driven by the growth in wireless and fiber-optic communications, information technology, and materials science. Communications, antenna, radar, and microwave engineers must deal with the generation, transmission, and reception of electromagnetic waves. Device engineers working
on
ever-smaller integrated circuits and at ever higher frequencies must take into
account
wave
propagation effects at the chip and circuit-board levels. Communication and
computer
network
engineers routinely use waveguiding systems, such as transmission lines
and
optical fibers. Novel recent developments in materials, such as photonic
bandgap
structures,
omnidirectional dielectric mirrors, and birefringent multilayer films, promise
a
revolution in the control and manipulation of light. These are just some
examples of
topics
discussed in this book. The text is organized around three main topic areas:
• The propagation, reflection, and transmission of
plane waves, and the analysis
and
design of multilayer films.
• Waveguides, transmission lines, impedance matching,
and S-parameters.
• Linear and aperture antennas, scalar and vector
diffraction theory, antenna array
design,
and coupled antennas.
The
text emphasizes connections to other subjects. For example, the mathematical
techniques
for analyzing wave propagation in multilayer structures and the design of
multilayer
optical filters are the same as those used in digital signal processing, such
as
the lattice structures of linear prediction, the analysis and synthesis of
speech, and
geophysical
signal processing. Similarly, antenna array design is related to the problem
of
spectral analysis of sinusoids and to digital filter design, and Butler beams
are
equivalent
to the FFT.
Bài giảng chi tiết Lý thuyết và kỹ thuật Anten
1. MUC LUC
Chương 1 Các nguồn bức xạ nguyên tố 2
1.1 Quá trình vật lý của sự bức xạ sóng điện từ của anten
1.2 Đipol điện
1.3 Đipol từ
1.4 Nguyên tố bức xạ hỗn hợp
Chương 2 Lý thuyết anten chấn tử 9
2.1 Phân bố dòng, áp trên chấn tử đối xứng
2.2 Đặc tính hướng của anten chấn tử
- Độ rộng búp sóng
- Hệ số định hướng
2.3 Các tham số của anten chấn tử
- Điện trở bức xạ
- Trở kháng vào
- Độ dài hiệu dụng
Bài giảng chi tiết Trường điện từ và truyền sóng
Chương 1 TRƯỜNG ĐIỆN TỪ
Chương 2 SÓNG ĐIỆN TỪ PHẲNG
Chương 3 NHỮNG VẤN ĐỀ CHUNG VỀ TRUYỀN SÓNG
Tuesday, March 15, 2011
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