2.1 Discrete-time LTI Systems : The Convolution Sum （卷积和） 2.1.1 The Representation of Discrete-Time Signals in Terms of impulses

1. is absolutely summable, 2. has finite energy

Chapter 1 Signals and Systems (1) A simple RC circuit Source voltage Vs and Capacitor voltage Vc (2) An automobile

6.23 Shown in Figure 6.23 is for a lowpass filter. Determine and sketch the impulse response of the filter for each of the following phase characteristics:

4.3 4.4 4.10 4.11 4.14 4.15 4.24 4.25 4.32 4.35 4.36 4.37 4.43

3.1 3.13 3.15 3.34 3.35

作业： 1.14 1.15 1.16 1.17 1.21 (d) (e) (f) 1.22 (d) (g) 1.23 1.24 (a) (b) 1.26 (a) (b) 1.27 1.31

A. Listen to the recording two or three times then think over the following questions:

Text A Part I Pre-reading Listen to a song named “Big Yellow Taxi”sung by singer Amy Grant

Unit 7 Part Ⅰ Pre-reading activities Part Ⅱ Text A Part Ⅲ Text B Part Ⅳ Post-reading activities