测试信号英文版课件：Chapter2-Lecture-1-Key-Points

1、Chapter 2 Discrete-Time Signals andSystems in the Time-DomainLecture 1 & 2Key PointsDiscrete-Time SignalsTime-domain representationMathematical functionSequences inside the braces with an arrow indicating t=0Graphical representation2Discrete-Time SignalsHow to obtain the sampled-data signal from the

2、 analog signal? SamplingHow to obtain the digital signal from the sampled-data signal? Quantification and encoding3Discrete-Time Signals:Time-Domain Representationreal sequence & complex sequencefinite-length & infinite-length sequenceleft-sided sequence & right-sided sequencecausal sequence & anti-

3、causal sequence4Basic OperationsProduct (modulation) operation:Modulatorxnynwn5Basic OperationsAddition operation:AdderMultiplication operationMultiplierAxnynxnynwn6Basic OperationsTime-shifting operation:where N is an integerIf N 0, it is delaying operationUnit delayIf N 0, it is an advance operati

4、onUnit advanceynxnynxn7Basic OperationsTime-reversal (folding) operation:Branching operation: Used to provide multiple copies of a sequencexnxnxn8up-samplingdown-sampling9LMBasic OperationsFriendly Reminder时间域的运算，使用“画图”的方式求解一般不易错 (For the time-domain operations on sequences, it is better to utilize the graphical representation for solving such problems)稍微复杂的时间域的操作，都是由基本的简单操作组合