通信原理知识点总结

Outline

2012.5

Chapter 0

 Basic elements of communication systems (p.2)

 Primary communication resources (p.3)

 The mobile radio channel (p.18)

 Block diagram of digital communication system (p.22)

 Shannon’s information capacity theorem (p.23-24)

Chapter 1

 Definition and basic concepts of random process

 Stationary and non-stationary

 Mean, correlation, and covariance functions, the mean-square value and variance

 The concept of ergodic process

 Transmission of a random process through a linear time-invariant filter

 dtXhtY)()()(

 The mean, autocorrelation function, and mean-square value of Y

 Power spectral density

 Definition (Equ. 1.38)

 Input-output relation (Equ. 1.39)

 Einstein-Wiener-Khintchine relations (Equ. 1.42, 1.43)

 Properties

 Gaussian process (Equ. 80)

 Concept of white noise

 Representation of narrowband noise

 The canonical form (Equ. 1.100)

 Properties of the in-phase and quadrature components (p. 65-66)

 Representation using envelop and phase components (Equ. 1.105-1.107)

 Basic concepts of Rayleigh distribution and Rician distribution

 Uncorrelated and statistically independent (p.58)

 Uncorrelated: Covariance is 0

 Statistically independent: defined by joint probability density function

Chapter 2

 Concepts of amplitude modulation and angle modulation (FM and PM)

 AM

 AM signal (Equ. 2.2 and Fig. 2.3), and the amplitude sensitivity ka

 Conditions of correct detection (p. 90)  Spectrum of AM wave (Equ. 2.5 and Fig. 2.4)

 Transmission bandwidth BT = 2W

 Virtues and limitations of AM

 Linear modulation schemes

 The general form (Equ. 2.7)

 DSB

 DSB signal (Equ. 2.8 and Fig. 2.5)

 Spectrum of DSB wave (Equ. 2.9 and Fig. 2.6)

 Coherent receiver

 Basic knowledge of costas receiver

 Basic concept of quadrature-carrier multiplexing

 Basic concepts of SSB and VSB

 Concepts of mixer (Fig. 2.16)

 Concepts of FDM

 Definitions of angle modulation

 FM

 A nonlinear modulation process

 Single-tone FM modulation

 Definitions of f, 

 Basic knowledge of narrowband and wideband FM

 Transmission bandwidth

 Carson’s rule (Equ. 2.55)

 Know the universal curve

 Demodulation

 Frequency demodulation (a direct method) (Fig. 2.30)

 Know phase-locked loop (an indirect method)

 Definitions of SNR’s

 (SNR)I, (SNR)O, and (SNR)C

 Figure of merit (Equ. 2.81)

 Comparison of figure of merits between DSB-SC (Equ. 2.88) and AM (Equ. 2.95)

 Basic concepts of threshold effect of AM (p.138) and FM systems (p.149)

Chapter 3

 Sampling

 Definitions of the sampling period and sampling rate

 Instantaneous sampling and the ideal sampled signal (Equ. 3.1-3.3, Fig. 3.2)

 Derivation of the interpolation formula (Equ. 3.4-3.9)

 The sampling theorem and definitions of Nyquist rate and Nyquist interval

 The methods of combat aliasing effect (p.187)

 PAM

 The difference between PAM and natural sampling

 The concept of “sample and hold”

 The PAM signal (Equ. 3.10-3.19)  The aperture effect

 Know PPM and PDM

 Quantization

 Quantization noise and (SNR)O of a uniform quantizer (Equ. 3.25-3.33)

 PCM

 Basic concepts

 Discrete in both time and amplitude

 Sampling, quantizing, and encoding

 Non-uniform quantizers

 -law and A-law

 Piecewise linear approximation to the companding circuit

 Five types of line codes and their waveforms

 Differential encoding

 Noise in PCM systems

 Know that noise including channel noise and quantization noise, and that

performance is essentially limited by the quantization noise

 Concepts of TDM (Fig. 3.19)

 Know the basic concept of digital hierarchy (p.214) and that the basic rate is 64

kbps

 Concepts of DM and delta-sigma modulation

 Concepts of linear prediction and linear adaptive prediction

 DPCM and its processing gain (Equ. 3.82)

Chapter 4

 Two sources of bit errors: ISI and noise

 Matched filter

 Frequency response (Equ. 4.14) and impulse response (Equ. 4.16)

 Properties: the peak SNR dependents only on signal energy-to-noise psd ratio

at the filter input

 Error rate due to noise

 Derivation of Equ. 4.35

 The complementary error function (Equ. 4.29)

 The result with equiprobable input signals (Equ. 4.38-4.40)

 The baseband data transmission system model (Fig. 4.7 and Equ. 4.44-4.48)

 Nyquist’s criterion

 The Nyquist’s criterion (p.262)

 The ideal Nyquist channel (Equ. 4.54-4.56 and Fig. 4.8, 4.9)

 Raised cosine spectrum (Equ. 4.59, Fig. 4.10)

 The definition of  and the bandwidth BT

 Correlative-level coding (partial response signaling)

 Duobinary signaling (class I partial response)

 Basic concepts (Fig. 4.11, 4.13, Equ. 4.66, 4.71)