Free Essay

Phase Modulation

In: Science

Submitted By jmicd11
Words 332
Pages 2
Phase Modulation
Phase Modulation “is used in many applications to carry both analogue and digital signals. Keeping the amplitude of the signal constant, the phase is varied to carry the required information or signal” (Poole, Radio-Electronics.com). An advantage of phase modulation is that it is easier compared to Frequency modulation. A Phase modulator is used in determining velocity of moving targets by extracting Doppler information. Doppler information needs a stable carrier which is possible in phase modulation but not in frequency modulation. A disadvantage of Phase modulation is that a frequency multiplier is needed in order to increase Phase modulation.
Quadrature Amplitude Modulation
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.
“QAM is a signal in which two carriers shifted in phase by 90 degrees are modulated and the resultant output consists of both amplitude and phase variations. In view of the fact that both amplitude and phase variations are present; it may also be considered as a mixture of amplitude and phase modulation” (Poole, Radio-Electronics.com). There are more disadvantages with QAM then there are advantages. One disadvantage is it is more susceptible to noise because the states are closer together so that a lower level of noise is needed to move the signal to a different decision point. Also, “when a phase or frequency modulated signal is amplified in a radio transmitter, there is no need to use linear amplifiers, whereas when using QAM that contains an amplitude component, linearity must be maintained. Unfortunately linear amplifiers are less efficient and consume more power, and this makes them less attractive for mobile applications” (Poole, Radio-Electronics.com).
Reference
Poole, Ian. (203). QAM-What is Quadrature Amplitude Modulation. Retrieved from http://www.radio-electronics.com

Similar Documents

Premium Essay

In Analog Technology, Compare and Contrast the Advantages and Disadvantages of Amplitude Modulation, Frequency Modulation, Phase Modulation, and Quadrature Amplitude Modulation

...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......

Words: 729 - Pages: 3

Free Essay

Advantages of Phase Modulation

...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......

Words: 14272 - Pages: 58

Free Essay

Modulation

...Introduction Modulation is the process of encoding information from a message source in a manner suitable for transmission.It involves translating a baseband message signal to a bandpass signal at frequencies that are very high compared to the baseband frequency. Baseband signal is called modulating signal.Bandpass signal is called modulated signal. In telecommunications, modulation is the process of conveying a message signal, for example a digital bit stream or an analog audio signal, inside another signal that can be physically transmitted. Modulation of a sine waveform transforms a baseband message signal into a passband signal. A modulator is a device that performs modulation. A demodulator  is a device that performs demodulation, the inverse of modultion. A modem (from modulator–demodulator) can perform both operations. Types of modulation • Analog modulation • Digital modulation Analog modulation- The aim of analog modulation is to transfer an analog baseband (or lowpass) signal, for example an audio signal or TV signal, over an analog bandpass channel at a different frequency, for example over a limited radio frequency band or a cable TV network channel. • Digital modulation The aim of digital baseband modulation methods, also known as line coding, is to transfer a digital bit stream over a baseband channel, typically a non-filtered copper wire such as a serial bus or a wired local area network. AMPLITUDE......

Words: 2983 - Pages: 12

Free Essay

Team Paper

...amplitude modulation, frequency modulation, phase modulation, and Quadrature Amplitude Modulation (QAM). Refrences: Electronics and Radio Today. (n.d.). Retrieved from http://www.electronics-radio.com/articles/radio/modulation/amplitude_modulation/am.php Electronics and Radio Today. (n.d.1). Retrieved from http://www.electronics-radio.com/articles/radio/modulation/frequency_modulation/fm.php M.S. Richer. (2006). Advantages/disadvantages/applications of various Modulation Schemes [Multimedia]. Retrieved from M.S. Richer, http://www-ee.uta.edu/dip/Courses/EE4330/comparison%20of%20modulation%20methods.pdf website. Radio-Electronics.com. (n.d.). Retrieved from http://www.radio-electronics.com/info/rf-technology-design/modulation-techniques/itu-designations-types-of-radio-emissions-transmissions.php Amplitude Modulation Amplitude modulation (AM) is a technique used in electronic communication. The most common use for this is in radio. AM works by varying the strength of the transmitted signal in relation to the information being sent ("Electronics and Radio Today", n.d.). Advantages: There are several advantages of amplitude modulation, and some of these reasons have meant that it is still in widespread use today. It is simple to implement, it can be demodulated using a circuit consisting of very few components, and AM receivers are very cheap as no specialized components are needed ("Electronics and Radio Today", n.d.). Disadvantages: Amplitude......

Words: 985 - Pages: 4

Free Essay

Analog and Digital Comparison Paper

...signals (digital) using standard phone lines. Amplitude Modulation & Frequency Modulation Analog and Digital signals can now be understood as types of signals, or wave forms that are used to transmit the audio or visual information from one place to another. The next step is understanding how the signals (wave forms) can vary and the advantages and disadvantages of those wave forms modulation types, in either a transmitted or received signal. Two types of modulations are Amplitude Modulation (AM) and Frequency Modulation (FM). The textbook defines ‘amplitude’ as a measure of the height of the wave (signal), which indicates the strength, or power, of the signal, and ‘frequency’ as the number of oscillations per second of an electromagnetic wave (Goleniewski, 2007). AM signals are known to modulate in amplitude by the signal that is to be transmitted. FM signals are known to modulate in frequency by the signal that is to be transmitted. Although it is cheaper, AM has poorer sound quality and in FM, it is much more reliable security wise because the signal can be encrypted (Poole, 2015). These are just a few of the advantages and disadvantages, and depending on the transmission modulations and signals being used, meeting the endpoint can be determined from these factors, as far as clarity of signal goes for audio and video. Phase Modulation (PM) Phase Modulation (PM) is the modulation technique in which carrier phase varies based on analog baseband information......

Words: 1984 - Pages: 8

Free Essay

Ese 576 Final Project Report

...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: ...............................................................

Words: 1587 - Pages: 7

Premium Essay

Pro Wycliff

...n Analog Technology, Compare and Contrast the Advantages and Disadvantages of Amplitude Modulation, Frequency Modulation, Phase Modulation, and Quadrature Amplitude Modulation 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.......

Words: 342 - Pages: 2

Free Essay

Electronic

...1. Define angle modulation and list its subcategories. Answer: Angle modulation is defined as modulation where the angle of a sine-wave carrier is varied from its reference value. The subcategories are Phase modulation and Frequency modulation. 2. What is the difference between frequency and phase modulation? Answer: The difference between frequency and phase modulation is; Frequency modulation is where the instantaneous frequency of a carrier is caused to vary by an amount proportional to the modulating signal amplitude, Phase modulation is the same but it is where the phase angle of a carrier is caused to depart from its reference value. 6. Define deviation constant. Answer: Deviation Constant is defined as in units of kHz/V. and it’s how much the carrier frequency will deviate for a given modulating input voltage level. 7. A 50-mV sinusoid, at a frequency of 1 kHz, is applied to a capacitor microphone FM generator. If the deviation constant for the capacitor microphone FM generator is 500 Hz/20 mV, determine: (a) The total frequency deviation. (±1.25 kHz) Answer: 50mV x (500 Hz)/(20 mV)= ±1.25 kHz (b) The rate at which the carrier frequency is being deviated. (1 kHz) Answer: The rate at which the carrier frequency is being deviated is ±1.25 kHz at a rate of 1 kHz. 8. Explain how the intelligence signal modulates the carrier. Answer: The intelligence signal modulates the carrier by the intelligence amplitude determines the amount of the......

Words: 300 - Pages: 2

Free Essay

A Comparison of Digital and Analog Technologies

...Different Modulations An amplitude modulated signal (AM) is created when the amplitude of the signal is varied in line with the variation intensity of the sound wave. An advantage to using this particular format is that it is the simplest of the modulations to implement. The most common issue with AM is the signal detects multiple levels of noise due to the detectors not being smart enough to cancel the noise during transmission. Even though amplitude modulation is simple to implement and is cheaper in cost, compared to other modulations it is not very effective and other modulations are preferred. It is however still used in communications such as broadcasting, two-way radio, and aircraft. Frequency Modulation (FM) transmits information over a carrier wave by varying its instantaneous frequency. In comparison to the amplitude modulation, the amplitude of the carrier is varied while its frequency remains constant. (Radio-Electronics, n.d.). One advantage of using this format is frequency modulation is resilient to noise. As noise is amplitude based, with a frequency modulation, the noise is reduced and only the frequency variations appear. The Frequency modulation is still an ideal format for many analogue applications. Most radio communications still use frequency modulation which is why there is still a demand for frequency modulation. A disadvantage to this modulation is it requires a more complicated demodulator that is more expensive than that of the AM. In Phase......

Words: 1049 - Pages: 5

Free Essay

Analog and Digital Comparison

...Comparing Analog Modulation Technologies With analog technology it is possible to send and receive digital information in a variety of formats. These include amplitude modulation, frequency modulation, phase modulation, quadrature amplitude modulation (QAM). All of these modulation methods transmit binary information using varying techniques and each has its own advantages and disadvantages. Generally these techniques operate on the idea that the current is being measured at steady intervals to determine the amplitude, frequency, or phase of the current’s wave. Each technique would has a standard current and deviates from that standard in some way in order to differentiate between bits of one or zero. The amplitude is the height of the wave and it indicates the signal strength (Goleniewski, 2007). Amplitude modulation represents the binary codes by presenting ones and zeros as either the presence or absence of a wave. Amplitude modulation is not always ideal because noise spikes can affect the signal reception and interfere with the transfer of data. With this type of modulation interrupted connections can also effect the data that is received because the absence of a signal may be interpreted as a zero. There is not an effective way to determine that the signal has been interrupted (Blanchard, 2001). The frequency is the oscillations of the wave per second, different frequencies operate at different oscillation speeds (Goleniewski, 2007). Frequency modulation......

Words: 1772 - Pages: 8

Free Essay

Modulation

...Chapter 5 Traditional Analog Modulation Techniques Mikael Olofsson — 2002–2007 Modulation techniques are mainly used to transmit information in a given frequency band. The reason for that may be that the channel is band-limited, or that we are assigned a certain frequency band and frequencies outside that band is supposed to be used by others. Therefore, we are interested in the spectral properties of various modulation techniques. The modulation techniques described here have a long history in radio applications. The information to be transmitted is normally an analog so called baseband signal. By that we understand a signal with the main part of its spectrum around zero. Especially, that means that the main part of the spectrum is below some frequency W , called the bandwidth of the signal. We also consider methods to demodulate the modulated signals, i.e. to regain the original signal from the modulated one. Noise added by the channel will necessarily affect the demodulated signal. We separate the analysis of those demodulation methods into one part where we assume an ideal channel that does not add any noise, and another part where we assume that the channel adds white Gaussian noise. 5.1 Amplitude Modulation Amplitude modulation, normally abbreviated AM, was the first modulation technique. The first radio broadcasts were done using this technique. The reason for that is that AM signals can be detected very easily. Essentially, all you need is a nonlinearity.......

Words: 6411 - Pages: 26

Free Essay

Osi Model

...Communication MODULATION 1 8/25/2013 Introduction Topics to be covered • Need for Modulation • What is Modulation? • Types of Modulation • Amplitude Modulation (AM) • Angle Modulation • Frequency Modulation (FM) • Phase Modulation (PM) 2 8/25/2013 Baseband vs Passband Transmission • Baseband Signal:- Information bearing Signal or Message Signal. • The term Baseband refers to the band of frequencies representing the original signal obtained from the source (or Base). – Voice (0-4kHz) – TV (0-6 MHz) • A signal may be sent in its baseband format when a dedicated wired channel is available. • Otherwise, it must be converted to passband. Need for Modulation • Size of the antenna • For efficient radiation, the size of the antenna should be λ/10 or more (preferably around λ/4 ), where λ is the wavelength of the signal to be radiated. • Easy to Multiplex • Several message signals can be transmitted on a given channel, by assigning to each message signal an appropriate slot in the channel. • Channel Selectivity • Each station can be assigned a suitable carrier so that the corresponding program material can be received by tuning to the station desired. 3 8/25/2013 Need for Modulation • Improved Signal to Noise Ratio • Will be dealt in future lectures • Less Fading of transmitted signal • As the energy of a signal is proportional to its frequency, fading by the atmospheric particle is less What is Modulation? • So for......

Words: 3221 - Pages: 13

Premium Essay

Team Week 2

...best to have end-to-end digital and end-to-end optical networks. Analog technology consists of amplitude modulation, frequency modulation, phase modulation, and Quadrature Amplitude Modulation (QAM). The advantages and disadvantages to each one. Advantages to amplitude modulation include simplicity to implement, it can be demodulated with a circuit consisting of hardly any components, and the receivers are inexpensive. Disadvantages of AM are it is not efficient when it pertains to power usage, low bandwidth, and high levels of noise. The advantages of frequency modulation are resilience to noise, resilience to signal strength, and are more efficient than most modes. The disadvantages of FM are it requires a more complex demodulator and contains less high data spectral efficiency than other modes. Advantages of phase modulation are it is simpler when compared to frequency modulation and more resistant to noise. One disadvantage is it is more difficult to encode and decode than AM and FM. A QAM advantage includes increase in efficiency of transmission of signals. A disadvantage is it more prone to noise. Modulation techniques are used for 56K modem, asymmetrical digital subscriber line, and Wi-Fi. Modulation is used in modems to transmit data signals over analog transmission lines. ADSL is capable of reaching 8Mbps while downloading and 1Mbps while uploading. The modulation comes in the form of QAM that allows users to use their frequency band. Wi-Fi allows users to connect......

Words: 2307 - Pages: 10

Free Essay

Team Week 2

...best to have end-to-end digital and end-to-end optical networks. Analog technology consists of amplitude modulation, frequency modulation, phase modulation, and Quadrature Amplitude Modulation (QAM). The advantages and disadvantages to each one. Advantages to amplitude modulation include simplicity to implement, it can be demodulated with a circuit consisting of hardly any components, and the receivers are inexpensive. Disadvantages of AM are it is not efficient when it pertains to power usage, low bandwidth, and high levels of noise. The advantages of frequency modulation are resilience to noise, resilience to signal strength, and are more efficient than most modes. The disadvantages of FM are it requires a more complex demodulator and contains less high data spectral efficiency than other modes. Advantages of phase modulation are it is simpler when compared to frequency modulation and more resistant to noise. One disadvantage is it is more difficult to encode and decode than AM and FM. A QAM advantage includes increase in efficiency of transmission of signals. A disadvantage is it more prone to noise. Modulation techniques are used for 56K modem, asymmetrical digital subscriber line, and Wi-Fi. Modulation is used in modems to transmit data signals over analog transmission lines. ADSL is capable of reaching 8Mbps while downloading and 1Mbps while uploading. The modulation comes in the form of QAM that allows users to use their frequency band. Wi-Fi allows users to connect......

Words: 2307 - Pages: 10

Free Essay

Comparison of Analog and Digital Technology

...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......

Words: 2102 - Pages: 9