1st Lecture SP.pdf

Signal Processing 1st Lecture Md. Toukir Ahmed Lecturer, Dept. Of IRE, BDU. 8/14/2024 ICT 4355: Signal Processing (1st Lecture) 1 Discussion about the Course Outline and Text Book 8/14/2024 ICT 4355: Signal Processing (...

Signal Processing 1st Lecture Md. Toukir Ahmed Lecturer, Dept. Of IRE, BDU. 8/14/2024 ICT 4355: Signal Processing (1st Lecture) 1 Discussion about the Course Outline and Text Book 8/14/2024 ICT 4355: Signal Processing (1st Lecture) 2 What is Signal? A signal is a function of one or more variables that indicate some (usually physical) phenomenon. Signal serves as carriers of information between communication devices. They can convey different types of information depending on the application required. These signals can be of different forms. 8/14/2024 ICT 4355: Signal Processing (1st Lecture) 3 Examples of Signals: Human voice and sound waves. Voltage in electrical circuits Room temperature controlled by a thermostat system Position, speed, and acceleration of an aircraft Accelerometers measured with accelerometers in mobile phones Force measured with force sensors in robotic systems Electromagnetic waves used to transmit information in wireless computer networks Digital photographs Digital Music Recording. 8/14/2024 ICT 4355: Signal Processing (1st Lecture) 4  Types of Signals: There are different types of signals which are given below: Analog Signals Digital Signals Real and Complex Signals Deterministic and Random Signals Periodic and Non-periodic Signals 8/14/2024 ICT 4355: Signal Processing (1st Lecture) 5 1. Analog Signals These signals are continuing (e.g., a real variable) and infinitely varying with time parameter or can take any value within a given range. These signals are represented by the sine wave. Examples of analog signals are audio signals, temperature readings, sound waves or television waves. Fig. 1: Analog Signals 8/14/2024 ICT 4355: Signal Processing (1st Lecture) 6 2. Digital Signals A signal that is a function of discrete variables (e.g., an integer variable) is said to be discrete time and this are represent in binary form (0s and 1s). More robust against noise. Commonly used in computer systems and telecommunications. Fig. 2: Digital Signals 8/14/2024 ICT 4355: Signal Processing (1st Lecture) 7 2. Digital Signals A signal that is a function of discrete variables (e.g., an integer variable) is said to be discrete time and this are represent in binary form (0s and 1s). More robust against noise. Commonly used in computer systems and telecommunications. Fig. 2: Digital Signals 8/14/2024 ICT 4355: Signal Processing (1st Lecture) 8 For Tutorial Class: Real and Complex Signals Deterministic and Random Signals Periodic and Non-periodic Signals 8/14/2024 ICT 4355: Signal Processing (1st Lecture) 9 Signal Parameters: Some of the signal parameters are: Amplitude Frequency Phase Wavelength 8/14/2024 ICT 4355: Signal Processing (1st Lecture) 10 Signal Parameters: Some of the signal parameters are: Amplitude Frequency Phase Wavelength 8/14/2024 ICT 4355: Signal Processing (1st Lecture) 11 Digital Signal Processing: Below figure shows two good ideas for signal processing. Digital signal processing of analog signals requires that we use an analog to digital converter (ADC) to sample the analog signal before processing and a digital-to-analog converter (DAC) to convert the processed digital signal back to Analog form. Fig.3: Analog Signal to Digital Signal 8/14/2024 ICT 4355: Signal Processing (1st Lecture) 12 Signals and Notation Different signals and its notation are given below: Basic Signals Periodic Signals Functional signals Geometric signals Basic Signals The basic signals are: Unit Step Unit Impulse Signals Unit Ramp signal Unit parabolic signal 8/14/2024 ICT 4355: Signal Processing (1st Lecture) 13 What is a Unit Step Signal? A unit step signal is also the step signal and one of the standard testing signals. A unit step signal is a specific type of input signal used for analysis, testing and designing. The magnitude of the unit step signal is one. A unit step signal can exist only for positive values and zero for negative values. In other words, let f(t) be a function, then the value of f(t) will be 1 for t>0 (i.e., for positive values of t ) and it will be zero for t=0 f(t) = 0 ; for t=0 f(n) = 0 ; for n