...Advantages and disadvantages of the following analog modulation techniques: In analog technology, compare and contrast the advantages and disadvantages of amplitude modulation, frequency modulation, phase modulation, and Quadrature Amplitude Modulation Amplitude Modulation When dealing with communication modulation is the process of altering one or more of the three primary parameters of a message signal. Modulation of message signals allow for the signal to be imbedded into a carrier signal that can be physically transmitted. The three primary parameters are amplitude, frequency, and phase. When dealing with analog modulation techniques each one that is used will have advantages and disadvantages. The amplitude modulation (AM) technique is based on the transformation of the highs and lows of a signal wave or its strength. This technique has the advantages of being able to travel long distances by bouncing off of structures as well as the atmosphere. The main disadvantage of this modulation technique is that is highly susceptible to signal interference from other electronic devices and waves creating and unclear signal, these interferences are what is known has noise. Frequency modulation (FM) is that of what its names says it is the altering of the frequency of a baseband signal. Altering the number of times each second that the current changes direction; comes with the advantage of being less susceptible to noise unlike that of AM. Also unlike AM, FM is not...
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...Python Reference Manual Release 2.3.3 Guido van Rossum Fred L. Drake, Jr., editor December 19, 2003 PythonLabs Email: docs@python.org Copyright c 2001, 2002, 2003 Python Software Foundation. All rights reserved. Copyright c 2000 BeOpen.com. All rights reserved. Copyright c 1995-2000 Corporation for National Research Initiatives. All rights reserved. Copyright c 1991-1995 Stichting Mathematisch Centrum. All rights reserved. See the end of this document for complete license and permissions information. Abstract Python is an interpreted, object-oriented, high-level programming language with dynamic semantics. Its high-level built in data structures, combined with dynamic typing and dynamic binding, make it very attractive for rapid application development, as well as for use as a scripting or glue language to connect existing components together. Python’s simple, easy to learn syntax emphasizes readability and therefore reduces the cost of program maintenance. Python supports modules and packages, which encourages program modularity and code reuse. The Python interpreter and the extensive standard library are available in source or binary form without charge for all major platforms, and can be freely distributed. This reference manual describes the syntax and “core semantics” of the language. It is terse, but attempts to be exact and complete. The semantics of non-essential built-in object types and of the built-in functions and modules are described in the Python...
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...reduction of a very simple front-end block for the calculus of phase transition metrics on a continuous phase modulation (CPM) receiver. A quasi-optimum receiver of very low complexity is attained by splitting the function of the optimum receiver bank filters in two blocks: calculus of projections coefficients on a low dimensional space of Walsh functions followed by simple matrix calculus. A sequence detection algorithm follows this block. The presented approach enables the reduction of the matched filters or correlators to just two integrators, regardless of the CPM scheme. Research on the reduction limits of the space dimension is conducted using catastrophic M-ary CPM schemes, taking advantage of their very low number of phase states. Performance of 1REC h=1/2 16-ary scheme is for the fist time presented. A rule is defined concerning the number of Walsh functions that must be used. That outcome proves to be valid for two CPM schemes of high power gain. The receiver is tested under additive white gaussian noise (AWGN). The carrier frequency is fc, where ωc=2πfc, ϕ0 is the arbitrary initial phase and Es is the energy per symbol, related with the bit energy by Es=log2(M)⋅Eb. Channel symbols are γi∈{±1, ±3, ⋅⋅⋅, ±(M-1)}, forming the M-ary sequence γ . Each symbol γi carries log2(M) bits as a result of a natural mapping of the information bits stream α. The information carried by NS channel symbols is keyed in signal’s phase: ϕ (t , γ ) = 2π...
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...Introduction: Kinect is a mainly a motion sensing input device. In this project it is used to enable control and interact with the application without the need to touch the object, through a natural user interface and using gesture and spoken commands may be. The Microsoft Kinect consists of an infrared projector, a color camera, an infrared sensor and Multi-array microphone that enables to: 1) Acoustic source localization 2) Ambient noise suppression Camera characteristics (1): The depth sensor captures video data in 3D under any ambient light conditions: 1) Infrared laser projector 2) Monochrome CMOS sensor Different depth measurement techniques are there. Here is a brief discussion about each of them: Lets first talk about the stereo triangulation method: (A stereo camera system can be used for determining the depth to points in the scene. Now first have to know what stereo camera is and what the features are. (A stereo camera is a type of camera with two or more lenses with a separate image sensor or film frame for each lens. This allows the camera to simulate humanbinocular vision, and therefore gives it the ability to capture three-dimensional images, a process known as stereo photography. Stereo cameras may be used for making stereoviews and 3D pictures for movies, or for range imaging. The distance between the lenses in a typical stereo camera (the intra-axial distance) is about the distance between one's eyes (known as the intra-ocular distance)...
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...Review Questions for Test-2 (Partial List) Part-A End-of-Chapter-4 Questions (match questions, overlook number mismatch) 1. How does analog data differ from digital data? Computers produce digital data that are binary, either on or off. In contrast, telephones produce analog data whose electrical signals are shaped like the sound waves they transfer. Analog data are signals that vary continuously within a range of values (e.g., temperature is analog). 1. Clearly explain the differences between analog data, analog transmission, digital data, and digital transmission. Data can be transmitted through a circuit in the same form they are produced. Most computers, for example, transmit their data through digital circuits to printers and other attached devices. Likewise, analog voice data can be transmitted through telephone networks in analog form. In general, networks designed primarily to transmit digital computer data tend to use digital transmission, and networks designed primarily to transmit analog voice data tend to use analog transmission (at least for some parts of the transmission). 4. How does baseband differ from broadband? Baseband is the digital transmission of binary electrical pulses. Broadband is the analog waveform used for transmission. 4. What is coding? Coding is the representation of one set of symbols by another set of symbols. In data communications, this coding is a specific arrangement of binary 0s and 1s used to represent...
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...different languages people can speak all over the world. Without proper translation and understanding, the conversation is pointless; this analogy is similar for analog and digital transmissions. Beginning with an analog signal, which is a continuous variable along amplitude and frequency. Analog circuits need to have a defined frequency band in which it operates. Different modulation schemes can vary the speed in which they operate, the quality of wire they require, the immunity to noise, and their overall complexity. The variety of modulation schemes in existence can be a disadvantage as this means many incompatibilities can exist within a single application. Such modulations include: * Amplitude modulation (AM) - modem relies on amplitude and associates high amplitude/zeros with low amplitude. Amplitude modulation can be demodulated using a circuit consisting of very few components but lacks a bit of quality, much like with AM radio frequencies. * Frequency modulation (FM) - modem altars the frequency value and decodes original bit patterns based on the frequency of the received signal. Frequency modulation has the advantage that, as amplitude variations do not carry any information on the signal, it can be...
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...to the electrical charge from electrons through the flow of holes that leads to current. As in the waterfall analogy, the rate at which the water is falling is similar to the current flow in a circuit. The third important characteristic of electricity is resistance, which refers to the amount of opposition to the flow of electrons. Higher is the value of resistance in electrons flowing. According to OHMS, these three characteristics are related by the equation V=I* R [pic] Analogy of the OHMS law with the water flow model. Analogy vs. Digital Modulation The main aim of analog modulation is to transfer and analog low pass signals. For example, audio signal or television signals over an analog band pass channel, a limited radio frequency band or a cable television network channel. The main aim of digital modulation is to transfer a digital bit stream over an analog band pass channel. For example, over the public switched...
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...ESE 576 Final Project Report ESE 576 Digital Communication System Final Project Report Learning of Gaussian Minimum Shift Keying Carrier Modulation (GMSK) Name: XX ESE 576 Final Project Report Content (1). Background and Motivation: ............................................................... 3 1. FSK:....................................................................................................... 3 2. CPFSK/CPM: ......................................................................................... 3 3. MSK:............................................................................................. 3 4. GMSK: ................................................................................................... 3 (2). Theoretical Analysis:........................................................................... 4 1 CPM:....................................................................................................... 4 2.CPFSK 3. MSK: ...................................................................................................... 5 4. GMSK: ................................................................................................... 5 (3). Simulation and Interpretation: ............................................................. 5 1. Modulation：.......................................................................................... 6 2. Demodulation： ...............................................................
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...Chapter 1 Basic Networking Chapter 1 Basic Networking: Data communication is the transfer of data from one device to another via some form of transmission medium. A data communications system must transmit data to the correct destination in an accurate and timely manner. The five components that make up a data communications system are the message, sender, receiver, medium, and protocol. Text, numbers, images, audio, and video are different forms of information. Data flow between two devices can occur in one of three ways: simplex, halfduplex, or full-duplex. A network is a set of communication devices connected by media links. In a point-to-point connection, two and only two devices are connected by a dedicated link. In a multipoint connection, three or more devices share a link. Topology refers to the physical or logical arrangement of a network. Devices may be arranged in a mesh, star, bus, or ring topology. A network can be categorized as a local area network (LAN), a metropolitan-area network (MAN), or a wide area network (WAN). A LAN is a data communication system within a building, plant, or campus, or between nearby buildings. A MAN is a data communication system covering an area the size of a town or city. A WAN is a data communication system spanning states, countries, or the whole world. An internet is a network of networks. The Internet is a collection of many separate networks. TCP/IP is the protocol suite for the Internet...
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...followed by the modulation and then reception at the receiver and making sure that there is no factor of signal degradation and noise. “The binary signal is made up of two symbols namely binary digits or bits 1 and 0. If there is no influence of noise and distortion during transmission, the binary information will be the same. The change in the signal is being measure at the receiver. Encoding is needless if the information to be transferred has already been converted in binary form just like in data communications. In contrary, voice communication through telephone is not in binary form. These are analog signals that vary in range of values and therefore must be converted to digital form before it is being used in digital communications system.” (T. T. (2011). Digital signal to analog signal conversions involve the use of DAC (Digital-to-Analog Converters). DAC accepts the discrete binary values and converts them into continuously-varying values of analog signal. This conversion may affect the fidelity of the signal if the process was not properly monitored. Analog telephone lines, most commonly called POTS lines, uses separate lines (e.g. standard phone and fax lines, alarm lines, etc.) from the digital equipment lines (e.g. PBX). The use of modem for computer’s connection to the internet is one of the best examples of conversion from analog to digital signals using standard phone line. Advantages and Disadvantages of Common Modulation Techniques ...
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...Analog and Digital Comparison Paper Current technology utilizes many different types of transmission cable such as fiber optics, coaxial cable, and twisted pair copper wire. These different types of cables use different communications techniques that maximize their efficiency. For instance, fiber optics can carry digital signals over long distances without amplification or repeaters required. Copper wire, on the other hand, carrying analog signals requiring amplification and noise corrections along the way in much shorter intervals. The result is there is a mix of transmission lines that require special software and equipment such as codecs and modems to convert and move data from one point to another. Codecs and Modems The most common form of analog to digital conversions uses multiplex devices and coder-decoder devices otherwise known as codecs. These programs receive analog signals from sine waves such as audio communications and code them as digital signals. These signals then travel to other locations with codec or modem devices that decode or decompress the data back to analog signals. Digital devices use modems or combinations of codecs and modems to modulate the data signals to analog signals to travel to other modems for demodulation back to digital data. The codec is “software that is used to compress or decompress a digital media file, such as a song or video” (Microsoft, 2014). This process is the same in telecommunications systems, which consist of the encoder...
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...Analog and Digital Comparison Paper Current technology utilizes many different types of transmission cable such as fiber optics, coaxial cable, and twisted pair copper wire. These different types of cables use different communications techniques that maximize their efficiency. For instance, fiber optics can carry digital signals over long distances without amplification or repeaters required. Copper wire, on the other hand, carrying analog signals requiring amplification and noise corrections along the way in much shorter intervals. The result is there is a mix of transmission lines that require special software and equipment such as codecs and modems to convert and move data from one point to another. Codecs and Modems The most common form of analog to digital conversions uses multiplex devices and coder-decoder devices otherwise known as codecs. These programs receive analog signals from sine waves such as audio communications and code them as digital signals. These signals then travel to other locations with codec or modem devices that decode or decompress the data back to analog signals. Digital devices use modems or combinations of codecs and modems to modulate the data signals to analog signals to travel to other modems for demodulation back to digital data. The codec is “software that is used to compress or decompress a digital media file, such as a song or video” (Microsoft, 2014). This process is the same in telecommunications systems, which consist of the encoder...
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...• What are the various 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...
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...Performance Evaluation of OFDM System for Different Channel and Different Modulation Techniques Thesis Report Department of Electronic and Telecommunication Engineering (ETE) Submitted By Foysal Bin Wadud (T-093011) Gazi Shamsul Arefeen Shams (T-093016) Supervised By Engr. Mohammad Jashim Uddin Contact Information: Foysal Bin Wadud (Mamun), Dept. of ETE, International Islamic University Chittagong, Metric No.: T093011, Email: mamunmoon19@yahoo.com Contact No.: +8801717934676 Gazi Shamsul Arefeen (Shams) Dept. of ETE, International Islamic University Chittagong, Metric No.: T093016, Email: shams.ete@gmail.com Contact No.: +8801676848247 Contact Information of Supervisor: Md. Jashim Uddin Dept. Of ETE, International Islamic University Chittagong. Contact No. +8801716-823959 Email: jashimcuet@yahoo.com Abstract The demand for high-speed mobile wireless communications is rapidly growing. Orthogonal Frequency Division Multiplexing (OFDM) technology promises to be a key technique for achieving the high data capacity and spectral efficiency requirements for wireless communication systems in the near future. An Orthogonal Frequency Division Multiplexing (OFDM) scheme offers high spectral efficiency and better resistance to fading environments. In OFDM the data is modulated using multiple numbers of sub-carriers that are orthogonal to each other because of which the problems associated with other modulation schemes such as Inter Symbol Interference (ISI) and Inter Carrier Interference...
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...the direction that produces the larger current. 2. Incoherent Light: Electromagnetic radiant energy not all of the same phase, and possibly also consisting of various wavelengths. 3. Laser: A device that generates an intense beam of coherent monochromatic light (or other electromagnetic radiation) by stimulated emission of photons from excited atoms or molecules. Lasers are used in drilling and cutting, alignment and guidance, and in surgery; the optical properties are exploited in holography, reading bar codes, and in recording and playing compact discs. 4. Output Pattern: aka NA of light source directly relates to the energy coupled into the core of the optical fiber. 5. Output Power: Amount of power a component, circuit or system can deliver to a load. 6. Modulation Speed: In fiber optics, modulation is associated with the telecommunications and data transport of digital information signals and analog audio/video signals, in which the digital/analog signal(s) are transmitted within another sine wave form known as a "passband". Common references for analog include pulse-code modulation (PCM), amplitude modulation (AM) and frequency modulation (FM). Digital modulation technologies are accomplished by "keying" methods: Phase-shift keying (PSK), Frequency-shift keying (FSK), Amplitude-shift keying (ASK) and Quadrature-amplitude modulation (QAM). 7. Core Diameter Mismatch: The central part of an optical fiber that provides the transmission region for an optical...
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