Module 1 BSIT ELXT 2A PDF

**MODULE 1** ELX 211 ELECTRONICS COMMUNICATION COLLEGE OF TECHNOLOGY BACHELOR OF SCIENCE IN INDUSTRIAL TECHNOLOGY **DR. LEOPOLDO G. BESINIO JR.** Faculty **TABLE OF CONTENT** Page **MODULE 1 :...............................................................................................** 3...

**MODULE 1** ELX 211 ELECTRONICS COMMUNICATION COLLEGE OF TECHNOLOGY BACHELOR OF SCIENCE IN INDUSTRIAL TECHNOLOGY **DR. LEOPOLDO G. BESINIO JR.** Faculty **TABLE OF CONTENT** Page **MODULE 1 :...............................................................................................** 3 III\. Time Frame VII. Self-Evaluation**.......................................................................** 21 VIII\. Review of Concepts**................................................................** 22 IX. References**.............................................................................** 23 X. Pre-Test**..................................................................................** 24 XI. Post-Test**............................................................................\.....** 26 **MODULE 1** **I. Title :** OVERVIEW OF COMMUNICATION SYSTEMS **III. Time Frame :** 3 hrs. **IV. Introduction :** In today\'s fast-paced and interconnected world, the significance of human communication within the field of electronics cannot be overstated. As technology continues to evolve at an unprecedented rate, effective communication serves as the backbone for innovation, collaboration, and the successful implementation of electronic systems and solutions. The integration of electronics into various facets of daily life---ranging from consumer electronics and telecommunications to smart devices and advanced robotics---has fundamentally transformed how we interact with technology and with one another.. **V. Objectives :** Upon completion of this learning module, the student should be able to: 1. **Understand Communication Systems**: - Describe the fundamental components and classifications of communication systems, distinguishing between analog and digital systems. 2. **Signal Types and Properties**: - Identify and differentiate between various types of signals (continuous vs. discrete, periodic vs. aperiodic) and their key properties such as frequency, amplitude, and phase. 3. **Modulation Techniques**: - Explain the purpose and method of modulation techniques, demonstrating how modulation affects the transmission characteristics and performance of communication systems. 4. **Transmission Media**: - Analyze the different types of transmission media (guided and unguided) used in communication systems and evaluate their advantages and disadvantages in signal transmission. 5. **Signal Reception and Processing**: - Investigate the processes involved in signal reception, including demodulation and error detection, and discuss the challenges faced during the reception of signals over various communication channels. **VI. Learning Activities:** 1. **People communicate to convey their thoughts, ideas, and feelings to others.** 2. **Communication is the process of exchanging information.** 3. **Two of the main barriers to human communication are language and distance.** **Methods of communication:** **1.Face to face** **2.Signals** **3.Written word (letters)** **4.Electrical innovations:** **♣ Telephone** **♣ Internet (computer)** **The process of communication begins when a source (Human, Computer, Sensor, etc.) generates some kind of message or data that must be received by others** **The message is referred to as information, or an intelligence signal.** **This message, in the form of an electronic signal, is fed to the transmitter, which transmits it over the communication channel.** **The message is picked up by the receiver and relayed to another human or computer.** **Along the way, a random undesirable signals (noise) is added in the communication channel and in the receiver that degrades or interferes with the transmitted information**  **If the data is nonelectrical (human voice, television picture), it must be converted by an input transducer into an electrical waveform referred to as the baseband signal** ** For voice messages, a microphone is used to translate the sound into an electronic audio signal.** ** For TV, a camera converts the light information in the scene to a video signal** **Transmitter** **The transmitter is a collection of electronic components and circuits that converts the electrical signal into a signal suitable for transmission over a given medium or channel.** **Transmitters are made up of oscillators, amplifiers, tuned circuits and filters, modulators, frequency mixers, frequency synthesizers, and other circuits** **Communication Channel** **The communication channel is the medium by which the electronic signal is sent from one place to another.** **♣ Types of media include** **♣ Electrical conductors (Coaxial cables, Twisted pairs, AC power lines)** **♣ Optical Fiber** **♣ Underwater** **♣ Free space (usually referred to as Wireless or Radio )** **♣ Free-Space Optics (FSO)** **Attenuation** **A channel acts partly as a filter to attenuate the signal and distort its waveform** **Signal attenuation, or degradation, exists in all media** **The signal attenuation increases with the length of the channel. It is usually proportional to the square of the distance between the transmitter and receiver.** **The waveform is distorted because of different amounts of attenuation and phase shift suffered by different frequency components (Frequency-Selective Channels)** **Signals amplification, in both the transmitter and the receiver, is required for successful transmission.** **Noise** **Noise is random, undesirable electronic energy that degrades the system performance.** **The causes may be external and/or internal** **Internal noise: Results from thermal motion of electrons in conductors, random emission, and diffusion or recombination of charged carriers in electronic devices Internal noise can be reduced but can never be eliminated** **External noise: Interference from nearby channels Human-made noise generated by fluorescent lights, etc. Natural noise from lightning, solar radiation External noise can be minimized or even eliminated** **Receivers** **A receiver is a collection of electronic components and circuits that accepts the transmitted message from the channel and converts it back into a form understandable by humans/destination.** **Receivers contain amplifiers, oscillators, mixers, tuned circuits and filters, and a demodulator or detector that recovers the original intelligence signal from the modulated carrier.** **Transceivers** **A transceiver is an electronic unit that incorporates circuits that both send and receive signals.** **Examples are: Telephones Fax machines Cell phones Computer modems** **Electronic communications are classified according to whether they are** **1. One-way (simplex) or two-way (full duplex or half duplex) transmissions** **2. Analog or digital signals.** **Simplex** **Is The simplest method of electronic communication** **This type of communication is one-way, where one end transmits while the other receives only. Examples are: Radio TV broadcasting Remote Control** **Duplex Communication** **Most electronic communication is two-way and is referred to as duplex.** **When people can talk and listen simultaneously, it is called full duplex. The telephone is an example of this type of communication.** **Half Duplex** **The form of two-way communication in which only one party transmits at a time is known as half duplex.** **Examples are:** **♣ Police, military, etc. radio transmissions ♣ Citizen band (CB) ♣ Family radio ♣ Amateur radio** **Analog Signals** **An analog signal is a smoothly and continuously varying voltage or current (y-axis).** **It takes any value within some range** **Digital Signals** **Digital signals change in steps or in discrete increments. Most digital signals use binary or two-state codes.** **Signal Conversion** **Many transmissions are of signals that originate in digital form but must be converted to analog form to match the transmission medium. Digital data over the telephone network. Analog signals can also be transmitted digitally. They are first digitized with an analog-to-digital (A/D) converter. The data can then be transmitted and processed by computers and other digital circuits.** **MODULE 1** **I. Title :** BASIC SIGNAL CONCEPTS **III. Time Frame :** 3 hrs. **IV. Introduction :** Basic signal concepts are foundational principles in the field of signal processing, encompassing the definition, representation, and analysis of signals, which can be classified as continuous or discrete, analog or digital. Signals carry information and can originate from various sources, including audio, video, and sensor data. Understanding these concepts is crucial for applications in telecommunication, control systems, and data analysis, as they enable the effective transmission, storage, and manipulation of information. Key attributes such as amplitude, frequency, and phase play significant roles in characterizing signals, while techniques like Fourier analysis aid in frequency domain representation, allowing for a deeper understanding of signal behavior and processing strategies. **V. Objectives :** Upon completion of this learning module, the student should be able to: 1. Understand the fundamental characteristics of signals, including amplitude, frequency, and phase. 2. Analyze different types of signals, such as continuous and discrete signals, in various applications. 3. Explore the mathematical representation of signals using functions and transform techniques. 4. Investigate the effects of noise on signal integrity and the importance of signal processing. 5. Apply basic signal concepts to real-world scenarios, such as telecommunications and audio engineering, to enhance comprehension. **VI. Learning Activities:** **Basic Signal Concepts: *Types of Signals: Analog and Digital*** **Electronic signals are crucial for the operation of all electronic devices, ranging from the sound of a person's voice to TV and radio broadcasts, and even electrical currents. Electronic signals are able to transmit information between electronic devices in an analog or digital pattern. In electronics engineering, a signal is defined as a time-varying voltage or current that is also an electromagnetic wave transferring message. There are two types of signals used in electronics, such as analog and digital signals. Analog and digital signals, which can be in the form of time varying voltages and currents, are used to describe data. Signals can be also characterized with respect to frequency. In this article, we will discuss the definition, types, advantages, and disadvantages of analog and digital signals in detail.** **ANALOG SIGNAL** **An analog signal is a time-varying signal that may contain an infinite number of values within a continuous scale. In electronics, the voltage, current, or frequency of the signal can be modified to define the information. Analog signals are determined by the response to change of physical quantities, such as light, sound, temperature, position, pressure etc.** **DIGITAL SIGNAL** **A digital signal is a signal that can be expressed as a sequence of discrete values. It can only take only one value from a finite set of possible values at a given time. Digital signals are used in digital electronics, such as computing and data transmission devices.** **ANALOG ELECTRONICS** Basic analog electronic components are resistors, capacitors, inductors, diodes, transistors, and operational amplifiers (op amps). The circuits that are made by the combination of analog components are known as analog circuits. - Designing analog circuits is generally more challenging. - Analog circuits are more susceptible to noise with unexpected fluctuations in voltage. Little variations in the voltage level of an analog signal can generate major inaccuracies during operation - Analog signals are used in communication systems to transmit voice, data, images, and video information via a continuous signal. - Amplitude modulation and frequency modulation are two basic types of analog transmission. Amplitude modulation (AM) regulates the amplitude of the carrier signal and frequency modulation (FM) regulates the frequency of the carrier signal. **DIGITAL ELECTRONICS** Digital circuits are implemented into digital electronics, such as logic gates or more complex digital ICs (Integrated Circuits). - In digital circuits, data values are represented by two states, 0 and 1, with larger values represented by groups of binary bits. - Most digital circuits are synchronous, operating predictably with the use of a clock signal. - Digital circuits use a processor to manipulate the data. - In communication systems, digital signals facilitate data transfer over point-to-point or point-to-multipoint transmission channels. **ADVANTAGES OF ANALOG SIGNAL** - Easier to process. - Well-suited for audio and video transmission. - Higher density and able to generate more refined information. - It provides a more accurate representation of changes in physical quantities, such as sound, light, temperature, position, or pressure. - Analog communication systems are less sensitive in terms of electrical tolerance **DISADVANTAGES OF ANALOG SIGNAL** - Data transmission at long distances may result in undesirable signal disturbances. - It is prone to generation loss. - It is subject to noise and distortion, as opposed to digital signals which have much higher immunity **ADVANTAGES OF DIGITAL SIGNAL** - It can convey information with less noise, distortion, and interference. - Digital signal processing is more flexible, accurate and secure. - Digital signals can be easily stored on any magnetic media or optical media using semiconductor chips. - Digital signals can be transmitted over long distances. **DISADVANTAGES OF DIGITAL SIGNAL** - A higher bandwidth is required for digital communication. - DSP processes signals at high speeds and requires more sophisticated internal hardware resources. - These result in higher power dissipation compared to analog signal processing, which includes passive components that consume less energy. - Digital systems and processing are typically more complex. **VI. Learning Activities:** **Basic Signal Concepts: *Signal Properties: Amplitude, Frequency, Phase*** **Signals are the lifeblood of communication systems, and their representation i n different domains is crucial for understanding their behavior. In the time domain, signals are expressed as a function of time, showing how they change as time progresses. Conversely, in the frequency domain, signals are represented by their frequency content, illustrating the different frequencies that make up the signal and their respective amplitudes.** **MODULATION TECHNIQUES: HOW WE ADAPT SIGNALS FOR TRANSMISSION** **In satellite communications, modulation is the process of varying a carrier signal in order to transmit information. Amplitude Modulation (AM), Frequency Modulation (FM), and Phase Modulation (PM) are some of the basic modulation techniques. Each of these methods encodes information in the amplitude, frequency, or phase of the carrier wave, respectively.** **In AM, if we modulate a carrier of 2 GHz with an audio signal of 1 kHz, the resulting spectrum will show the carrier at 2 GHz and two sidebands at 2 GHz ± 1 kHz.** **SIGNAL PROPAGATION: UNDERSTANDING HOW SIGNALS TRAVEL** **Signals, once transmitted, propagate through various media, which can affect their strength and quality. Free-space path loss is a key factor in satellite communications, describing the attenuation of signal power over distance.** **SIGNAL-TO-NOISE RATIO (SNR): THE METRIC OF COMMUNICATION QUALITY** Signal-to-noise ratio (SNR) is a measure that compares the level of the desired signal to the level of background noise. It is often expressed in decibels (dB). A higher SNR indicates a clearer signal. In satellite communications, maintaining a high SNR is crucial for ensuring reliable data transmission. **BANDWIDTH: THE HIGHWAY OF SIGNAL TRANSMISSION** Bandwidth refers to the range of frequencies within which a signal is transmitted or received. It is a key concept in satellite communications, as it determines the data rate and capacity of the communication channel. The bandwidth required for a signal can be estimated based on the data rate using Nyquist\'s theorem or Shannon\'s capacity theorem. **PHASE NOISE: THE STEALTHY SIGNAL DEGRADER** Phase noise is a type of signal noise that manifests as random fluctuations in the phase of a signal. It is particularly important in satellite communications, where a stable reference oscillator i s needed for signal generation and synchronization. Phase noise can degrade the performance of communication systems by causing errors in signal demodulation. **PHASE NOISE: THE STEALTHY SIGNAL DEGRADER** Phase noise is a type of signal noise that manifests as random fluctuations in the phase of a signal. It is particularly important in satellite communications, where a stable reference oscillator i s needed for signal generation and synchronization. Phase noise can degrade the performance of communication systems by causing errors in signal demodulation. A satellite transponder with a local oscillator suffering from phase noise might lead to a spreading of the signal\'s spectrum, causing interference with adjacent channels and reducing the system\'s overall performance. **PHASE NOISE: THE STEALTHY SIGNAL DEGRADER** Phase noise is a type of signal noise that manifests as random flucBy understanding these fundamental concepts and properties of signals, one can begin to grasp the complexities of satellite communications and the challenges faced in designing and operating these systems. **DEFINITION OF MODULATION** Modulation is the process of varying a carrier signal\'s properties, such as amplitude, frequency, or phase, to encode information for transmission over communication channels. PURPOSE OF MODULATION The primary purpose of modulation is to enable the efficient transmission of signals over long distances, allowing for better utilization of bandwidth and reducing interference from noise. **TYPES OF MODULATION TECHNIQUES** Common modulation techniques include Amplitude Modulation (AM), Frequency Modulation (FM), and Phase Modulation (PM), each with unique characteristics and applications in communication systems **Definition of Amplitude Modulation** Amplitude Modulation ( AM ) Is a technique used to encode information in the amplitude of a carrier wave, allowing the transmission of audio and other signals over long distances. **Key Characteristics of AM** AM signals are characterized by their simplicity in implementation and the ability to be received by standard radio receivers, although they are more susceptible to noise and interference compared to other modulation techniques. **Applications of Amplitude Modulation** Common applications of AM include AM radio broadcasting, aviation communication, and certain types of two-way radio systems, where the modulation technique is effective for transmitting voice and audio signals. **FREQUENCY MODULATION (FM)** **Definition of Frequency Modulation Frequency Modulation (FM)** is a modulation technique where the frequency of a carrier wave is varied in accordance with the amplitude of the input signal, allowing for effective transmission of audio and data. **Key Characteristics of FM** FM signals are known for their resilience to noise and interference, providing superior sound quality compared to Amplitude Modulation (AM), making them ideal for high-fidelity audio broadcasting. **Applications of Frequency Modulation** Common applications of FM include FM radio broadcasting, television sound transmission, and two-way radio communications, where clarity and quality of audio signals are paramount. **Definition of Phase Modulation** Phase Modulation (PM) is a modulation technique where the phase of a carrier signal is varied in accordance with the amplitude of the input signal, allowing for effective transmission of information. **Key Characteristics of PM** PM signal are characterized by their ability to maintain signal integrity in the presence of noise, providing a robust method for transmitting data over various communication channels. **Applications of Phase Modulation** Common application of PM include digital communication systems, satellite communications, and certain types of data transmission where high fidelity and resistance to interference are required. **MODULE 1** **I. Title :** SIGNAL TRANSMISSION AND RECEPTION **III. Time Frame :** 3 hrs **IV. Introduction :** Signal transmission and reception are critical processes in modern communication systems that enable the transfer of information over various media, including wired and wireless channels. In this context, a signal is an encoded representation of data that can take various forms, such as electrical pulses, electromagnetic waves, or optical signals. Effective transmission involves modulating these signals to optimize bandwidth, improve signal-to-noise ratios, and ensure reliable delivery to the receiver. On the other hand, reception entails demodulating the signals, filtering out noise, and reconstructing the original information for interpretation. As technology advances, understanding the principles of signal transmission and reception becomes increasingly important for applications ranging from telecommunications and broadcasting to satellite communication and internet connectivity. **V. Objectives :** Upon completion of this learning module, the student should be able to: 1. Examine the principles of signal transmission, including modulation techniques and bandwidth considerations. 2. Analyze the various mediums for transmitting signals, such as electrical cables, optical fibers, and wireless channels. 3. Understand the mechanisms of signal reception, focusing on the role of antennas and receivers in capturing transmitted signals. 4. Investigate the challenges of signal degradation during transmission and explore strategies for signal enhancement and error correction. 5. Apply knowledge of signal transmission and reception to design efficient communication systems for diverse applications **VI. Learning Activities:** **Signal Transmission and Reception: *Transmission mediums: wired and wireless*** **A transmission medium is one which carries a signal from one computer to another. It is also known as communication channel. Wired transmission media includes twisted pair cable, Ethernet cable, coaxial cable and optical fibre whereas wireless transmission media includes microwave, radio wave, satellite, infrared, Bluetooth, WIFI etc.** **Transmission media can be grouped in two categories:** **1) Wired or Guided transmission media It includes cables i.e. Twisted pair cable, Ethernet cable, Coaxial cable and Optical fibre etc.** **2) Wireless or Unguided transmission media It includes waves through air, water or vacuum i.e. Infrared, Radio link, Microwave link, Satellite link, Bluetooth, WIFI etc.** **Wired or Guided transmission media** Some of the wired transmission media are discussed below: **1. Twisted Pair Cables** This is one of the common forms of wiring in networks, especially in LANs and it consists of two insulated wires arranged in a regular spiral pattern (double helix). It is generally used for telephone communications in offices and also in modern Ethernet networks. For telephonic communication a Voice. Grade Medium (VGM) cable is used but for LAN applications a higher quality cable known as Data Grade Medium (DGM) is used. The twisting of wires reduces crosstalk which is the bleeding of a signal from one wire to another. This crosstalk can corrupt the signal and hence cause network errors. In addition to preventing internal crosstalk, the twisting of wires also protects the signal from external interference which affects both the wires and also creates unwanted signals. **2. Coaxial Cables-** It is the most commonly used transmission media for LANs. It consists of solid wire cores surrounded by one or more foil or wire shields, each separated by some kind of plastic insulator. The inner core carries the signal and the shield provides the ground. It has high electrical properties and is suitable for high speed communication. It is widely used for television signals and also by large corporations inbuilding security systems. Multi-channel television signals can be transmitted around metropolitanareas at considerably less cost. The two most common types of Coaxial cables are Thicknet and Thinnet. **3. Optical Fibres** These consists of thin strands of glass or glass like material which are so constructed that they carrylight from a source at one end of the fibre to a detector at the other end. The light sources used are eitherlight emitting diodes (LEDs) or laser diodes (LDs). The data to be transmitted is modulated onto a lightbeam using frequency modulation techniques. At the receiver\'s end, the signals are demodulated.Optical fibres offer a very high bandwidth and this makes it capable of multichannel communication. Fibre Optic cable can be of two types: i\) Single node fibre optic cable: It supports a segment length of up to 2kms and bandwidth of up to100Mbps ii\) Multinode fibre optic cable: It has a segment length of 100kms and bandwidth of 2Gbps. The Optical fibre consists of three layers: i\) Core - glass or plastic through which the light travels ii\) Cladding - covering of the core that reflects the light back to the core iii\) Protective (Buffer) coating-protects the fibre cable from hostile environments **Wireless Transmission Media** Wireless or unbounded or unguided media transport electromagnetic waves without using a physical conductor. The signals are broadcasted through air or water and thus are available to anyone that has a device capable of receiving them. Some of the wireless media are: 1. **Infrared** Infrared is the frequency of light that is not visible to human eye. It has a range of wavelengths, just like visible light has wavelengths from red light to violet light. Far infrared waves are thermal. This is the reason we feel the heat from sunlight, a fire or a radiator. Shorter, near infrared waves are not hot at all in Page 5 of 8 fact we can\'t even feel them. These shorter wavelengths are the ones used by your TV remotes. Infrared communication requires a transceiver (a combination of transmitter and receiver) in both devices that communicate. Infrared communication is playing an important role in wireless data communication due to the popularity of laptop computers, personal digital assistants(PDAs) , digital cameras , mobile phones , pagers and other devices. Infrared is used in Night Vision Camera,Remote control, File sharing between two phones, Communication between a PC and peripheral device, But being a line-of-sight transmission, it is sensitive to fog and other atmospheric conditions. **Radio waves** Radio is the transmission of signals through free space by modulation of electromagnetic waves with frequencies below those of visible light. Inradio wave transmission, certain radio frequencies are allocated to private/government organizations for direct voice communications. Each radio Page 6 of 8 signal uses a different frequency and this differentiates it from others. The transmitter takes some message, encodes it and then transmits it with radio wave. The receiver on the other hand receives the radio waves and decodes it. Both the transmitter and the receiver use antennas to radiate and capture the radio signal. Radio transmission is widely used by delivery services, policemen, security personals etc. **Microwaves** Microwave permits data transmission rates of about 16 gigabits per second. This type of transmission uses high frequency radio signals to transmit data through space. Microwaves offer a line of sight method of communication. A transmitter and receiver of a microwave system are mounted on very high towers and both should be visible to each other (line of sight) In case of microwave transmission, curvature of the earth, mountains and other structures often block the line of sight. **Satellites** Satellites can carry a large amount of data in addition to TV signals. Satellite communication is a special use of microwave transmission system. A satellite is placed precisely at 36000 km above the equator where its orbit speed exactly matches the earth\'s rotation speed. Hence it always stays over the same point with respect to the earth. This allows the ground station to aim Page 8 of 8 its antenna at a fixed point in the sky. The ground station consists of a satellite dish that functions as an antenna and communication equipment to transmit (called Uplink) and receive (called Downlink) data from satellites passing overhead. Such satellites can cost \$60 million to build but only three of them are needed to cover the entire earth\'s surface. Capacity or number of channels used in satellite communications depends on the frequency used. Typical data transfer rates are 1 to 10 Mbps. Satellites are especially used for remote locations, which are difficult to reach with wired infrastructure.