Signal and System I Signal energy and power Instantaneous power Energy in time interval t1 to t2 Average power in time interval t1 to t2 Total energy Average power over infinite period
Signal and System I Signal energy and power– discrete time Instantaneous power Energy in time interval N1 to N2 Average power in time interval N1 to N2 Total energy Average power over infinite period
Signal and System I Transform of the independent variable (1) Time-shift New point located at
Signal and System I Transform of the independent variable New point located at (1) Time-shift
Signal and System I Transform of the independent variable New point located at (2) Time-reversal
Signal and System I Transform of the independent variable New point located at (3) Scale
Signal and System I Example /3 2/3
Signal and System I Periodical signal Even and odd signals even odd Any signal has its even and odd signal part Even part Odd part
Signal and System I Exponential and Sinusoidal signals a>0, exponentially increase with t. Real exponential:C, and a are real numbers a<0, exponentially decrease with t. Complex exponential:C, and a are real numbers Euler’s relation:
Signal and System I Exponential and Sinusoidal signals Energy in one period: Average power:
Signal and System I Exponential and Sinusoidal signals, discrete-time a>0, exponentially increase with n. Real exponential:C, and a are real numbers a<0, exponentially decrease with n. Complex exponential:C, and a are real numbers Periodicity properties of discrete-time complex exponential: 0 has a period of 2 N has a period of 2 / 0
Signal and System I Example:
Signal and System I Discrete-time unit impulse and unit step function Unit impulse Unit step
Signal and System I Discrete-time unit impulse and unit step function
Signal and System I continuous-time unit impulse and unit step function Unit impulse Unit step
Signal and System I continuous-time unit impulse and unit step function
Signal and System I Continuous-time and discrete-time systems Continuous-time Discrete-time System diagram and properties will be discussed in later chapters.