Signals and Systems
Punch record sheet 3312min
| date | Check in | schedule |
|---|---|---|
| 2023.1.8 | √ | 1.8% |
| 2023.1.9 | √ | 2.8% |
| 2023.1.10 | √ | 4.0% |
| 2023.1.11 | ||
| 2023.1.17 | God, I'm so lazy |
(1) Overview of signals and systems
1.0 Common Trigonometric Formulas
- as knowledge supplement
1.1 Signals and systems
- Signal: the manifestation of a message
- System: A whole with specific functions composed of several interacting or interdependent things.
1.2 Representation and classification of signals
- Representation of signal: expression f(t) (function of time) / waveform (image drawn by the function)
| Signal classification | describe | express |
|---|---|---|
| OK signal | There is a definite function expression |  |
| random signal | Function expression not determined |  |
| continuous signal | The independent variable is within the defined range, excluding some discontinuous points, and a certain function value can be obtained for any independent variable. |  |
| discrete signal | A discrete signal with equal intervals of independent variables defined only on certain discrete values is often called a sequence f(k) k=0,±1,±2,±3...called a sequence number |
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| periodic signal | Within the defined interval, changes are repeated according to the same rules every certain time T or positive number N. |    |
| non-periodic signal | Not cyclical | |
| real signal | The signal function value is a real number | |
| complex signal | The signal function value is a complex number |  |
| energy signal power signal |
Continuous Signals - Integrating Discrete Signals - Summing |
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1.3 Basic signals
1.4 Signal operation
- Signal operations
| Operation classification | describe | – |
|---|---|---|
| Addition and multiplication of signals | ||
| calculus of signals | ||
| Difference of discrete signals | ||
| Accumulation of discrete signals | ||
| Signal deconvolution shift | ||
| signal scaling |
- Signal arithmetic comprehensive questions