Free Essay

Analog Versus Digital

In: Computers and Technology

Submitted By josemgiralt
Words 2433
Pages 10
| Analog and Digital Comparison | NTC/362 Fundamentals in Networking | EDWARD BROWN | Jose Giralt | 3/18/2013 |

|

A signal is simply the transmission of data from one place to another place. In our day to day life we deal with various signals constantly like signals from music, power lines, telephones, and cellular devices. Analog and digital are two kinds of signals which are used for the transmission of information from source to destination. Usually the information to be transmitted from one place to another is either audio or video. This information signal is then transformed into those signals which can be transmitted via different channels.
For the analog format, the data is transformed into electrical pulses with varying amplitude while for the digital format; the data is transformed into binary format representing two amplitudes. We have various such equipment like analog or digital phones, fax machines, modems, clocks, watches etc. Analog technology is the older one and has been used for decades. It is cheap too but the problem with analog signals is that there is a limitation on the size of the data that can be transmitted at any given point of time.
With the advent of digital technology many improvements and new techniques have been introduced. Now days almost every appliance or equipment is based on digital technology. In this, the transmitter translate the data into binary form and the receiver re assemble and produces the original information signal. Digital signal as compared to analog gives us more options as it can be easily computed and manipulated by software. Also digital signals are frequently used in telecommunication. Instead of having various advantages over analog signal, digital signal lag behind in quality. Since in digital devices there is translating and reassembling of data because of this reason its quality is not that good. But with new technologies we can possibly remove errors and noise in the digital signal. But digital is quite expensive as compared to analog and working is going on globally to reduce its price.
Digital to Analog conversions involve a conversion process with DAC. This devise takes the binary code converting it to the analog signal. Digital to analog signals can compromise the quality of the signal, if it is not actively monitored. Analog lines, which are also known as POTS lines usually support standard phone lines, fax machines or alarm lines, keeping them separate from the digital PBX equipment. An example of digital to an analog signal would be the use of a modem for Internet use that converts computer digital signals using POTS lines.

Advantages and Disadvantages of Common Modulation Techniques

Amplitude Modulation

Analog signals have four modulation techniques. The most simple of the four is Amplitude Modulation (AM). AM transmits data by varying the intensity of the waves. The most common use for AM is transmitting radio stations. AM is very simple by design that makes it the least costly method of transmitting data. The main disadvantage with AM is how easily the transmission can contain interference. AM signals also use more energy than other types of modulation methods.

Frequency Modulation

Frequency Modulation (FM) is also most commonly used in broadcasting radio stations. FM transmits data by using multiple frequencies of the signal as opposed to the varying the intensity wave. Using multiple frequencies makes FM transmissions less susceptible to line interference. Disadvantages of FM are the amount of bandwidth required. It is much higher than that of other methods. ANALOG SIGNALS
Analog signals are continuous electrical signals that vary with time as shown in figure. In other words an Analog signal is any continuous signal for which the time varying feature (variable) of the signal is a representation of some other time varying quantity, i.e. analogous to another time varying signal. It produces small fluctuations in the signal which are very useful and this lacks in digital signals. The resolution of analog signals is infinite. In real world, an analog signal is subject to noise and a finite slew rate. Therefore, both analog and digital systems are subject to limitations in resolution and bandwidth. As analog systems become more complex, effects such as non-linearity and noise ultimately degrade analog resolution to such an extent that the performance of digital systems may surpass it.
Telephone voice signal is analog. The variations in the analog signal are due to changing intensity in voice. At the receiving end, the signal is reproduced in the same proportion. Advantages of analog signals
The main advantage of analog signals is their fine definition which has the potential for an infinite amount of signal resolution. In comparison to digital signals, analog signals have higher density. Analog signals are easier and simpler to process as compared to complex digital signals. An analog signal can be processed directly by analog components, though some processes aren't available except in digital form. Analog signals are relatively easy to create and carry from place to place. Disadvantages of analog signals
The major disadvantage of analog signaling is that any system has noise, any random unwanted variation. As the signal is copied and re-copied, or transmitted over long distances, these random variations interfere with our signal and distort it. Electrically, these losses due to interference of noise can be diminished by shielding, good connections, and several cable types such as coaxial or twisted pair.
In the figure the blue lines represents the voltage capacity of signal to travel clearly and for this it must lie between minimum value of X and maximum value of Y.
Here the noise had distorted our signal. Noise is unwanted variations in the signal which deteriorates the quality of signal. The signal had crossed the limits of X and Y and lost its authentication. Noise is sometimes called "distortion" or "clipping". We can say that Noise creates loss in authentic information and produces distortion. If the pattern of our original signal is slightly altered by unwanted noise or distortion, the output will not be identical to the input. This is impossible to recover, because when we amplify the signal to recover attenuated parts of the signal amplifies the noise (distortion/interference) as well. Although the resolution of analog signals is higher than digital signals but the difference can be overshadowed by the noise in the signal. DIGITAL SIGNALS
Digital signals are the one which are non-continuous, change in individual steps. They consist of pulses or digits with discrete levels or values. The value of each pulse is constant, but there is an abrupt change from one digit to the next. Digital signals have two amplitude levels called nodes. The value of which are specified as one of two possibilities such as 1 or 0, HIGH or LOW, TRUE or FALSE and so on. In reality, the values are anywhere within specific ranges and we define values within a given range. In the Digital Revolution, the usage of digital signals has increased significantly. Many modern media devices, especially the ones that connect with computers use digital signals to represent signals that were traditionally represented as continuous-time signals; cell phones, music and video players, personal video recorders, and digital cameras are examples. In most applications, digital signals are represented as binary numbers, so their precision of quantization is measured in bits. Suppose, for example, that we wish to measure a signal to two significant decimal digits. Since seven bits, or binary digits, can record 128 discrete values , those seven bits are more than sufficient to express a range of one hundred values.
A. Transmission of digital signals
There are two ways to transmit digital data between one or several devices or communication participants, either parallel or serial transmission. Bit-parallel transmission:
In bit parallel transmission all the bits of information signal are transmitted at once at the same time. Bit-serial transmission
Serial transmission is a good for long distances. In this case, only one signal line transmits the bits one after the other. As a result, the transmission of information takes more time, which is nevertheless acceptable because, on the other hand, the installation effort and the costs are considerably reduced. Advantages of digital signal over analog signal
Digital signals consist of patterns of bits of information. These patterns can be generated in many ways, each producing a specific code. Modem digital computers store and process all kinds of information as binary patterns. All the pictures, text, sound and video stored in this computer are held and manipulated as patterns of binary values. Here the signal acquire two basic forms i.e. ON (high or 1) and OFF (low or 0). If we compare with analog these digital signals are more uniform. Here, we see the main advantage of digital over analog. Since the signal is very uniform, noise has not severely altered its shape or amplitude. The digital signal shows a far less change to the actual waveform than the previous analog signal. They are both shown below for a close comparison. We can say that main advantage of digital signals over analog signals is that the precise signal level of the digital signal is not vital. This means that digital signals are fairly immune to the imperfections of real electronic systems which tend to spoil analog signals. As a result, digital CD's are much more robust than analog LP's.
Codes are often used in the transmission of information. These codes can be used either as a means of keeping the information secret or as a means of breaking the information into pieces that are manageable by the technology used to transmit the code.
Thus we can say that though digital technology is expensive as compared to that of analog but because of various advantages and more options it has made analog technology redundant.
Disadvantage of digital signals
The one main drawback of digital communication is that they require greater bandwidth as compared to analog communication for the transmission of same signal.
Quadrature Amplitude Modulation (QAM)
Quadrature Amplitude Modulation or QAM is a form of modulation which is widely used for modulating data signals onto a carrier used for radio communications. It is widely used because it offers advantages over other forms of data modulation such as PSK, although many forms of data modulation operate alongside each other. Quadrature amplitude modulation, QAM may exist in what may be termed either analogue or digital formats. The analogue versions of QAM are typically used to allow multiple analogue signals to be carried on a single carrier. For example it is used in PAL and NTSC television systems. Digital formats of QAM are often referred to as "Quantized QAM" and they are being increasingly used for data communications often within radio communications systems. Radio communications systems ranging from cellular technology through wireless systems including WiMAX, and Wi-Fi 802.11 use a variety of forms of QAM
ADSL
ADSL is an asymmetrical service deployed over one twisted-pair. With ADSL, the majority of bandwidth is devoted to the downstream direction, from the network to the user, with a small return path that is generally sufficient to enable telephony or simple commands. ADSL is limited to a distance of about 3.5 miles (5.5 km) from the exchange point. With ADSL, the greater the distance, the lower the data rate; the shorter the distance, the better the throughput. New developments allow the distance to be extended because remote terminals can be placed closer to the customer. There are two main ADSL standards: ADSL and ADSL2. The vast majority of the ADSL that is currently deployed and available is ADSL. ADSL supports up to 7Mbps downstream and up to 800Kbps upstream. This type of bandwidth is sufficient to provide good Web surfing, to carry a low grade of entertainment video, and to conduct upstream activities that don’t command a great deal of bandwidth. However, ADSL is not sufficient for things such as digital TV or interactive services. For these activities, ADSL2, which was ratified in 2002, is preferred. ADSL2 supports up to 8Mbps downstream and up to 1Mbps upstream. An additional enhancement, known as ADSL2+, can support up to 24Mbps downstream and up to 1Mbps upstream.
Wi-Fi
Wi-Fi (also spelled Wifi or WiFi) is a popular technology that allows an electronic device to exchange data wirelessly (using radio waves) over a computer network, including high-speed Internet connections. The Wi-Fi Alliance defines Wi-Fi as any "wireless local area network (WLAN) products that are based on the Institute of Electrical and Electronics Engineers' (IEEE) 802.11 standards". However, since most modern WLANs are based on these standards, the term "Wi-Fi" is used in general English as a synonym for "WLAN".
The Synchronous Optical Network (SONET)
The Synchronous Optical Network (SONET) is a standard for optical transport that was formulated by the Exchange Carriers Standards Association (ECSA) for the American National Standards Institute (ANSI) which sets standards for telecommunications and other industries in the United States. The standard was originally initiated by Bellcore labs in 1984 on behalf of the Regional Bell Operating Companies (RBOC’s) for the following key purposes: The compatibility of equipment by all vendors who manufacture to a certain standard.
Synchronous networking
Enhanced operations, administration, maintenance and provisioning (OAM&P)
Efficient add/drop multiplexing (ADM)
Standards-based survival rings
Transport of new services, such as Asynchronous Transfer Mode (ATM)
North American Digital hierarchy (T x)
The North American Digital hierarchy starts off with a basic Digital Signal level of 64 KBPS (DS0). Thereafter, all facility types are usually referred to as "T x", where "x" is the Digital Signal level within the hierarchy. Up to the DS3 rate, these signals are usually delivered from the provider on Twisted-Pair or Coaxial cables. North American T1 service providers often refer to the signal interface between the User and the Network as "DS-1" signals. In the case of User to User interfaces, the term "DSX-1" is used to describe those DS1 signals at the "cross-connect" point. CONCLUSION
In conclusion, the benefits of using a digital system over analog is clear. Digital signals are easier to transmit and offer less room for errors to occur, vary less distortion in our original signal. This leads to accurate data transmission that in turn leads to faster transmission rates and better productivity.
REFRENCES
Telecommunications Essentials. The Complete Global Source, Second Edition Lillian Goleniewski , Kitty Wilson Jarrett http://en.wikipedia.org/wiki/Analog_signal http://en.wikipedia.org/wiki/Digital
http://www.radio-electronics.com/info/rf-technology-design/pm-phase-modulation/what-is-qam-quadrature-amplitude-modulation-tutorial.php

Similar Documents

Free Essay

Project 1

...Kevin Hall: Analog Vs Digital for Recording Music The research I have done addresses the recording industry's use of analog vs digital hardware to create music. My research has shown that the preferred method depends on many factors, personal & social to create the visions that they hear in their heads. Introduction What are the benefits of digital versus analog in the music recording industry that might be a very touchy question to some, as analog does have a very strong following. However over the past couple of years digital music recording has come into the foreground. In this research some of the questions regarding two different recording techniques will be answered. Literature Review After doing a bit of research, there seems to be very strong arguments for both sides. Some people feel the warmth and tone you get out of analog will never be duplicated. However, some of the newer school musicians feel that with modern technology that same warmth and tone can be achieved through digital means. Either way the music industry as a whole has benefited from both. According to Chiang (2013) “There is no doubt about it, recording to tape adds a certain characteristic to the sound.” And “it’s one of the great attributes of recording to tape. It adds certain fatness to the tracks, makes them feel alive.” However, on the other hand you have younger musicians usually going the route of digital. Like Dotree (2009) says” The untrained ear may not notice the......

Words: 1660 - Pages: 7

Free Essay

Analog and Digital Comparison

...Analog and Digital Comparison Technologies for analog-to-digital and digital-to-analog conversions There is no actual all analog or all digital telecommunications going on technologically today (Goleniewsk & Wilson Jarrett, 2007, Chapter Chapter 1, Analog Versus Digital Transmission). One day, developers hope to make the network 100% digital. Connecting to the internet or just making a call to your mother two states over is a mixture of both when it comes to communicating from one terminal to the next. That being said, it takes codecs and modems for a successful conversion to occur. Say you are calling another state from a land line. This call will start out analog at your telephone and then must be converted to digital. When you pick your phone up, it connects to a codec. Your voice can range from 100Hz to 10,000Hz depending on many factors. The average Hz a phone company will allot is 4,000 which works for virtually all people. Codec is short for coder-decoder and it works by minimizing the amount of bits per second that will carry the voice to the multiplexer. In the case of a cellular network, the data will have to be compressed even further so that the most efficient transmission can occur. The codec will then transfer the data to a multiplexer. This particular multiplexer is a TDM (time division multiplexer). This will allow for one channel to be open at a time. This does make sense since it would not be good to take over a phone line once it is......

Words: 1772 - Pages: 8

Free Essay

Abcd

...A hybird / digital software package for the solution of chemical kinetic parameter identification problems by ALAN M. CARLSON Electronic Associates, Inc. Princeton, New Jersey INTRODUCTION The modern hybrid computer offers many significant improvements over first generation hybrid systems These improvements include: 1. The increased speed of digital computers en- abling programs to be written in hybrid FORTRAN without drastically limiting hybrid solution rates. 2. The development of analog/hybrid software (e.g., hybrid simulation languages and analog set-up programs). The net result of these improvements has been an increase in the SCope and complexity of hybrid applications and a reduction in the effort required to program and debug hybrid problems. Unfortunately, the dev'elopment of hybrid applications software has not kept pace with recent hybrid improvements. Applications software for purposes of this discussion is defined as an integrated set of digital/hybrid programs capable of solving the majority of frequently occurring problems in a specific applications area. Based on this definition, little or no tangible information is currently available on the practicality of developing hybrid software packages although its benefits are obvious. In mid-1968, EAT's Princeton Computation Center initiated a development project to· determine the feasibility of hybrid applications software. The objectives of the project were to select a frequently......

Words: 8745 - Pages: 35

Free Essay

Analog and Digital Comparison Paper

...Analog and Digital Comparison Paper Amanda Dyer, Derick Campos, Jesse Ford, Mehran Gerami, Nicolas Monteiro, Wendell Taylor NTC/362 October 15, 2015 Richard Swafford, Jr. Analog and Digital Technology: A Comparison Analog and digital are two different types of signals used to transmit audio or visual information from one place to another. Analog signals are continuous, meaning that there are no breaks or interruptions and digital signals are not continuous, they use specific values to represent information (Strickland, 2008). Analog transmissions are sent via electronic pulses of varying amplitude, while digital transmissions are converted into binary format to represent two individual amplitudes. Analog is cheap and has been used quite some time now, but the biggest issue with analog signals is the limitation of data that can be transmitted. Nowadays almost all equipment being produced is digital based. Analog to digital conversions or A/D conversions is the process of changing a continuous variable signal to a multi-level signal without altering the vital contents or the information or data. A prime example of a telecommunication that uses this form of conversion is a telephone modem. Voice communications vary in range and are not in binary form, so these analog signals must be translated into digital signals. Digital to analog conversions or DAC is the conversion of binary code to analog signal. In order words, signals having few defined levels or states......

Words: 1984 - Pages: 8

Free Essay

Technology

...modulation techniques? Begin your explanation with frequency-shift keying and move to multilevel QAM.   During this week’s readings I have found 4 different modulation techniques:   Amplitude modulations, frequency modulation, phase modulation, and quadrature amplitude modulation.  While these have different modulation schemes that branch out, these are the primary used modulations I have found. Amplitude modulation is when different amplitudes are used to represent the digital bitstream in analog format.    Modems rely on amplitude modulation to determine the high amplitude that is represented by ones and low amplitudes that are represented by zeros.  They also rely on amplitude modulation to determine the difference in the amplitudes so the receiving device can put out the message in the correct way.  Frequency modulation is also known as FSK, or frequency-shift key.  FSK’s uses two different frequencies to distinguish between a mark digital 1 and a space digital 0 when transmitting on an analog line.  It is used on modems that operate at 1,200bps or slower (Goleniewski, 2007).       Phase modulation modifies a sine wave, also known as a carrier, to allow it to carry information.  The phase of the sine wave is changed to fit the type of information that is being transferred.  Phase modulation can be paired with carrierless amplitude for ADSL, or Asymmetrical DSL. Last Quadrature Amplitude Modulation is a “single-carrier scheme that modulates both the amplitude and......

Words: 940 - Pages: 4

Free Essay

Historical Exploration

...or samples. The result is called digital representation. Strictly speaking, digitizing means simply capturing an analog signal in digital form. For a document the term means to trace the document image or capture the "corners" where the lines end or change direction. The term digitization is often used when diverse forms of information, such as text, sound, image or voice, are converted into a single binary code. Computers predate to the Digital Age. Prior to the 1950s, computers were analog, using vacuum tubes. Later, vacuum tubes were used in conjunction with diodes. Like the digital computers that came later, analog computers used binary logic, but instead of being directly controlled by a program consisting of 1s and 0s, the state of the vacuum tube was changed by a change in voltage. The voltage change was analogous to a 1 (power on) versus a 0 (power off). In 1956, MIT built the TX0, the first general-purpose, programmable computer to use transistors. Digitization occurs in two parts: Discretization and Quantization. Discretization is the reading of an analog signal A, and, at regular time intervals (or frequency), sampling the value of the signal at the point. Each such reading is called a sample and may be considered to have infinite precision at this stage. Quantization is when the samples are rounded to a fixed set of numbers (such as integers). Data Communications There are many different ways in which analog converts to digital. For example, signals are......

Words: 977 - Pages: 4

Free Essay

Audio Convergence

...Audio Recording Convergence and the Digital Age Final Project Abstract With information technology advancements and a more computer savvy world, the audio recording medium and digital medium have merged, changing the sound recording industry forever. This convergence has blurred the line between professional and amateur sound recordings. Technology has made new products smaller, feature rich and more affordable where anyone can record their music and offer it on the web for the whole world to enjoy. This medium convergence has closed the gap between musicians and listeners and brought forth a famine in the recording industry, which in turn, has brought new opportunities to the dying market. What does this mean to us? In short terms, with new digital formatting software available to anyone, the compression of music waves, and the technological advances, the recording industry is struggling to stay afloat. This statement is pretty remarkable, being that the world’s leading recording engineers are having difficulties keeping business alive with the evolution of technology. It is evident, recording engineers need to step backwards to differentiate themselves and find better innovative ways to keep the recording business profitable. This transformation in the world of recording, is affecting all of us as both consumers and producers of audio content. The following research paper discusses these convergence changes with a short look into......

Words: 1562 - Pages: 7

Premium Essay

Introduction of Fiber Optic

...their advantages over traditional copper. commspecial.com edu Guide Communications Specialties, Inc. is committed to increased education and knowledge in the Pro A/V and Broadcast industries. We hope that you enjoy reading – and learning! – with our eduGuide series of educational resources. For additional information on these and other industry related technologies, please visit us at commspecial.com today! ©2009 Communications Specialties, Inc. All Rights Reserved. Specifications, claims or other product information contained in this document are subject to change without notice. This document may not be reproduced, in whole or in part, without the express written consent of Communications Specialties, Inc., Fiberlink, Pure Digital Fiberlink, the starburst logo, Scan Do and Deuce are registered trademarks of Communications Specialties, Inc. CSI and the triangle designs are trademarks of Communications Specialties, Inc. October 8, 2009 Table of Contents A Brief Introduction ............................................................................................................ 2 Advantages of Fiber Optic Systems .............................................................................. 3 Optical Transmitters ........................................................................................................... 5 The Optical Fiber ................................................................................................................. 8......

Words: 5977 - Pages: 24

Free Essay

Sar Adc

...sampling without switch bootstrapping and extra reset voltage. Furthermore, a dual-supply voltage scheme allows the SAR logic to operate at 0.4 V, reducing the overall power consumption of the ADC by 15% without any loss in performance. The ADC was fabricated in 0.13- m CMOS. In dual-supply mode (1.0 V for analog and 0.4 V for digital), the ADC consumes 53 nW at a sampling rate of 1 kS/s and achieves the ENOB of 9.1 bits. The leakage power constitutes 25% of the 53-nW total power. Index Terms—ADC, analog-to-digital conversion, leakage power consumption, low-power electronics, medical implant devices, successive approximation. I. INTRODUCTION EDICAL implant devices, such as pacemakers and implantable cardiac defibrillators, target increasingly advanced signal acquisition and signal processing systems. Such devices, which are to be implanted in the human body, require extremely low power consumption in order to operate up to 10 years or more [1]. Analog-to-digital converters (ADCs) are among the most critical and power hungry components of medical implant devices for measurements of various electrophysiological signals (DC to a few kHz [2]). Conversion of the low-frequency analog signals does not need high speed, but requires ultra-low-power operation (e.g., in nW range). This combined with the required conversion accuracy makes the design of such ADCs a major challenge. So far, most of the research on ADCs has been focused on moderate and particularly high-speed......

Words: 5927 - Pages: 24

Premium Essay

Physical Security

...reporting suspicious people. Aiding in identifying people as known versus unknown are identification systems. Often photo ID badges are used and are frequently coupled to the electronic access control system. Visitors are often required to wear a visitor badge. Examples of Physical Security ATMs (cash dispensers) are protected, not by making them invulnerable, but by spoiling the money inside when they are attacked. Thieves quickly learned that it was futile to steal or break into an ATM if all they got was worthless money covered in dye. Safes are rated in terms of the time in minutes which a skilled, well equipped safe-breaker is expected to require to open the safe. These ratings are developed by highly skilled safe breakers employed by insurance agencies, such as Underwriters Laboratories. In a properly designed system, either the time between inspections by a patrolling guard should be less than that time, or an alarm response force should be able to reach it in less than that time. Hiding the resources, or hiding the fact that resources are valuable, is also often a good idea as it will reduce the exposure to opponents and will cause further delays during an attack, but should not be relied upon as a principal means of ensuring security. Physical Security Electronic Access Physical Security software and hardware facilitates the capture, transmission, viewing, recording, archiving, and management of analog and IP video sources and provides electronic access......

Words: 2139 - Pages: 9

Free Essay

Digitalisation of Cable Tv

...growth in number of TV channels combined with the inherent limitations of the analog cable TV systems has posed several challenges to the cable TV sector,mainly due to capacity constraints and non-addressable nature of the network.With time and evolution of technology, new addressable digital TV platforms like DTH,IPTV etc. are now available.The evolution of technology has also paved the way for bringing about digitization with addressability in the cable TV sector. The digitization of cable TV is a step forward towards the removal of the shortcomings of the analog cable TV systems like the non-addressability and the capacity constraints. In the digital addressable systems, service providers can offer more channels and consumers can select the channels of their choice.Also, the digital addressable system opens out additional business opportunities to the service providers in the form of value added and interactive services. It would enable provision of broadband and triple play (voice, video and data) services. In addition,other stakeholders in the value chain would also potentially benefit - broadcasters by way of increase in subscription revenues, government via increase in service tax collections, and customers from an enhanced television viewing experience. What does Digitization mean? Digitization is a process which converts the information into digital format. In this format, information is organized into discrete......

Words: 7623 - Pages: 31

Free Essay

Assignments

...Chapter 4: Digital Transmission (Line coding, Block coding, Scrambling) Digital to digital conversion (Line Coding) Converting a sequence of data bits (text, numeric, audio, or video) into a digital signal, at the sender, then recovering the original bit sequence from the signal, at the destination data rate  bit rate(N) b/s, signal rate(S)  baud ratechange/s (Hz) Let r bit/change, Nmax = S * r * 1/c where c is and usually assumed ½ For the average calculations of S&N The goal is to increase the data rate (information flow) while decreasing band rate (better utilization of channel BW, cheaper links) Factors to consider in digital signaling: Long strings of 0‘s or 1‘s causes a drift of the obtained baseline, hence ―baseline wandering‖ that leads to incorrect bit decoding. 1) Baseline wandering: The receiver averages the signal power (Baseline), and uses it to decode the received signal bit value. 2) DC components: Constant level for long period of time creates very low frequency components in the frequency spectrum, that might not pass through some medium (e.g., TP of 200Hz 3000Hz). Hence, we need to remove the DC from the Digital Signal . 3) Self-Synchronization: To match the sender and receiver clocks, hence match the bit intervals at both ends for correct decoding. Transitions in the digital signal act as self-synch altering the receiver to the start, mid, or end of the bit, resetting its clock in case it is out of synch. 4) Built in error detection: It is good......

Words: 2727 - Pages: 11

Free Essay

Power Electronics

...2. Hardware of the fuel cell control system Hardware of the control system consists of the following blocks: 1) Central processing unit, 2) Analog inputs, 3) Digital inputs, 4) Analog outputs, 5) Digital outputs, 6) RS 232 serial port. The hardware is capable of controlling 32 analog inputs which consist of temperature and pressure inputs. It is also used to process 16 digital inputs (i.e. start, stop and Emergency stop…) and to control 16 digital outputs (i.e. switch valves, alarm signals…) and 6 analog PWM outputs. Overall block diagram of fuel cell control system is shown in Fig.1. 2.1. Central processing unit and data controller Control system has been composed of a main board which relies on an ATmega128 microcontroller. This microcontroller has the following practical characteristics [3]: • Functional frequency of 16MHZ. • Eight analog inputs. • Six PWM outputs. • Two serial ports. • 1 2.2. Temperature analog input unit Temperature processing unit consists of anode input temperature, cathode input temperature, stack body temperature and anode output temperature (condenser).A K-type thermocouple is used to control the temperature at fuel side and provide the temperature feedback. This unit has the capability to sense 16 temperatures instantaneously and precisely. To process and control these datas, they are transferred to the analog input unit of main board. Fig. 1. Overall block diagram of fuel cell control system. A tape heater adjusts the temperature of air and......

Words: 3037 - Pages: 13

Free Essay

Analog Circuit with Labview

... Analog Electronics with LabVIEW® By Kenneth L. Ashley ............................................... Publisher: Prentice Hall Pub Date: October 04, 2002 Print ISBN-10: 0-13-047065-1 Print ISBN-13: 978-0-13-047065-2 Pages: 432 Table of Contents | Examples Copyright National Improvements | Virtual Instrumentation Series Preface References Hardware and Software Requirements LabVIEW VI Libraries and Project and Problem Folders and Files Unit 1. Elementary Circuit Analysis for Analog Electronics Section 1.1. Resistor Voltage Divider and MOSFET DC Gate Voltage Section 1.2. Output Circuit and DC Drain Voltage Section 1.3. Frequency Response of the Amplifier Stage Section 1.4. Summary of Equations Section 1.5. Exercises and Projects Unit 2. Transistors and Voltage Amplification Section 2.1. BJT and MOSFET Schematic Symbols, Terminal Voltages, and Branch Currents Section 2.2. Fundamentals of Signal Amplification: The Linear Circuit Section 2.3. Basic NMOS Common-Source Amplifier Section 2.4. Transistor Output Resistance and Limiting Gain Section 2.5. Summary of Equations Section 2.6. Exercises and Projects Section 2.7. References to the Electronics Book Sequence Unit 3. Characterization of MOS Transistors for Circuit Simulation Section 3.1. Physical Description of the MOSFET Section 3.2. Output and Transfer Characteristics of the MOSFET Section 3.3. Body Effect and Threshold Voltage Section 3.4. Derivation of the Linear-Region Current – Voltage......

Words: 29147 - Pages: 117

Free Essay

Cis 246 Week 8 Final Exam

...CIS 246 Week 8 Final Exam Click Link Below To Buy: http://hwaid.com/shop/cis-246-week-8-final-exam/ Question 1. (TCO 2) The _____ is a specialized United Nations agency that regulates international telecommunications, including radio and TV frequencies, satellite and telephony specifications, networking infrastructure, and tariffs applied to global communications. IETF IANA ISP ITU Question 2. (TCO 12) When using an analog telephone, a VoIP adapter that performs analog-to-digital conversion is known as a(n) _____. VTA (voice telephone adapter) ATA (analog telephone adapter) DTA (digital telephone adapter) DTA (data telephone adapter) Question 3. (TCO 5) At the customer’s demarcation point, either inside or outside the building, T-carrier wire pairs terminate with a _____. terminal adapter smart jack CSU/DSU switch Question 4 (TCO 1) _____ is the means through which data is transmitted and received. Spam The network adapter Transmission media NOS Question 5. (TCO 12) _____ messaging is a service that makes several forms of communication available from a single user interface. Unified Instant Diversified Open Question 6. (TCO 12) _____ is the use of one network to simultaneously carry voice, video, and data communications. Multicasting Unicasting Divergence Convergence Question 7. (TCO 5) The portion of the PSTN that connects any residence or business to the nearest CO is known as the _____. demarcation...

Words: 1108 - Pages: 5