1绪论 Preface
1 绪论 Preface
Preface ● What is signa? asignal is a function of independent variables such as time, distance, position, temperature, pressure and So on
Preface ⚫ What is signal? ◆ A signal is a function of independent variables such as time, distance, position, temperature, pressure and so on
Preface ● What is signa? Signals play an important role in our daily life Examples of signals that we encounter frequency a Speech and music signals represent air pressure as a function of time at a point in space aa black-and-white picture is a representation of light intensity as a function of two spatial coordinates
Preface ⚫ What is signal? Speech and music signals represent air pressure as a function of time at a point in space. A black-and-white picture is a representation of light intensity as a function of two spatial coordinates. ……. ◆ Signals play an important role in our daily life. Examples of signals that we encounter frequency:
Preface e Why discuss the signal? o The signal carries information The objective of signal processing is to extract useful information carried by the signal o The method of information extraction depends on the type of signal and the nature of information being carried by the signal
Preface ⚫ Why discuss the signal? ◆ The signal carries information. ◆ The objective of signal processing is to extract useful information carried by the signal. ◆ The method of information extraction depends on the type of signal and the nature of information being carried by the signal
Preface e How do we obtain the desired signal o Most signals we encounter are generated by natural means A signal can also be generated synthetically or by computer simulation
Preface ⚫ How do we obtain the desired signal ? ◆ Most signals we encounter are generated by natural means. ◆ A signal can also be generated synthetically or by computer simulation