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Topic: Minimum-shift keying


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In the News (Tue 25 Jun 19)

  
 Gaussian minimum shift keying - Wikipedia, the free encyclopedia
Gaussian minimum shift keying or GMSK is a kind of continuous phase frequency shift keying.
GMSK has high spectral efficiency, but it needs higher power level than for instance Quadrature phase-shift keying (QPSK) to reliably communicate the same amount of data.
The baseband modulation is generated by starting with a bitstream 0/1 and a bit-clock giving a timeslice for each bit.
en.wikipedia.org /wiki/Gaussian_minimum_shift_keying   (248 words)

  
 Center for Wireless Telecommunications
Minimum Shift Keying (MSK) is continuous phase FSK with the smallest possible modulation index h.
The signals are transmitted using a Gaussian Minimum Shift Keying (GMSK) scheme.
GMSK is a form of binary signaling schemes which represent digital states as a shift between discrete sinusoidal frequencies called Frequency Shift Keying (FSK).
www.cwt.vt.edu /faq/gsm.htm   (568 words)

  
 Modulation - Wikipedia, the free encyclopedia
Indeed, MSK is a particular case of the sub-family of CPM known as continuous phase-frequency-shift keying (CPFSK) which is defined by a rectangular frequency pulse (i.e.
The use of on-off keying to transmit Morse code at radio frequencies is known as continuous wave (CW) operation.
One of the three key characteristics of a signal is usually modulated: its phase, frequency or amplitude.
www.wikipedia.org /wiki/Modulation   (709 words)

  
 Bandwidth-Efficient Modulation
In other words, the Gaussian minimum shift keying waveform is usually less power-efficient than more traditional waveforms such as binary phase-shift keying and requires a more complex receiver, but this potential reduction in power efficiency and increase in receiver complexity could be rewarded with a very significant enhancement of bandwidth efficiency.
With Gaussian minimum shift keying, input bits with rectangular (+1, -1) representation are converted to Gaussian (bell-shaped) pulses by a Gaussian filter before further smoothing by a frequency modulator.
Gaussian minimum shift keying is not new—the technique has been used extensively in Europe for cell-phone applications with a bandwidth–bit-time product of 0.3.
www.aero.org /publications/crosslink/winter2002/03.html   (2366 words)

  
 Modulation Basics
Gaussian minimum shift keying, the waveform that Aerospace proposed for the Advanced Extremely High Frequency program, is a form of continuous phase modulation.
Binary phase-shift keying takes each input bit individually and chooses one of two possible phases to represent that bit value—so for example, to send a "0," a phase of 0 degrees might be chosen, and to send a "1," a phase of 180 degrees might be chosen.
Frequency-shift keying has some attractive characteristics, but it generally does not use bandwidth very efficiently and is not suitable for applications where bandwidth efficiency is crucial.
www.aero.org /publications/crosslink/winter2002/03_sidebar2.html   (609 words)

  
 Modulation - Wikipedia, the free encyclopedia
Indeed, MSK is a particular case of the sub-family of CPM known as continuous phase-frequency-shift keying (CPFSK) which is defined by a rectangular frequency pulse (i.e.
The use of on-off keying to transmit Morse code at radio frequencies is known as continuous wave (CW) operation.
One of the three key characteristics of a signal is usually modulated: its phase, frequency or amplitude.
www.wikipedia.org /wiki/Modulated   (711 words)

  
 Modulation / Demodulation
GMSK differs from Minimum Shift Keying (MSK) in that a pre-modulation Gaussian filter is used.
The GMSK modulation has been chosen as a compromise between a fairly high spectrum efficiency (of the order of 1 bit/Hz) and a reasonable demodulation complexity.
A block diagram of a GMSK modulator in Figure 8.
tns-www.lcs.mit.edu /~turletti/gsm-overview/node12.html   (160 words)

  
 Minimum shift keying - Patent Storm
In the modulation and demodulation of a plurality of frequency separated channels on a radio frequency carrier by digitally coded speech or data, the speech or data is modulated on a digitally generated sub-carrier by quadrature phase shift keying and after conversion to analogue form the...
A continuous phase frequency shift keyed modulated signal with a modulation index of 0.5 is produced at the desired output...
In a direct sequence spread spectrum modulation apparatus, the data of predetermined bit inserted in a phase shift time data period provided between the respective PN codes, or a predetermined bit at the latter half portion of the PN code, is phase shifted in accordance with the data to be...
www.patentstorm.us /class/375/305-Minimum_shift_keying.html   (2633 words)

  
 Intersymbol interference - Wikipedia, the free encyclopedia
Some techniques try to reduce the amount of interference between consecutive symbols, such as Gaussian minimum shift keying and certain other phase-shift keying variants
The disturbance caused by extraneous energy from the signal in one or more keying intervals that interferes with the reception of the signal in another keying interval.
Extraneous energy from the signal in one or more keying intervals that interferes with the reception of the signal in another keying interval.
en.wikipedia.org /wiki/Intersymbol_interference   (302 words)

  
 Encyclopedia: Enhanced Data Rates for GSM Evolution
Gaussian minimum shift keying or GMSK is a kind of continuous phase modulation.
In addition to GMSK (Gaussian minimum-shift keying) EDGE uses 8PSK (8 Phase Shift Keying) for its upper five of the nine modulation and coding schemes.
In telecommunication, the term phase-shift keying (PSK) has the following meanings: In digital transmission, angle modulation in which the phase of the carrier is discretely varied in relation either to a reference phase or to the phase of the immediately preceding signal element, in accordance with data being transmitted.
www.nationmaster.com /encyclopedia/Enhanced-Data-Rates-for-GSM-Evolution   (1536 words)

  
 ECEn 485: Gaussian Minimum Shift Keying
Gaussian Minimum Shift Keying (GMSK) is a modification of MSK (i.e.
The Gaussian pre-modulation filter smooths the phase trajectory of the MSK signal thus limiting the instantaneous frequency variations.
In GMSK, this modulation method is modified by filtering the NRZ pulse train with a Gaussian low pass filter.
www.ee.byu.edu /ee/class/ee485/simulink/fsk-fm/fsk-fm.html   (685 words)

  
 Phase-shift keying - Wikipedia, the free encyclopedia
Phase-shift keying (PSK) is a digital modulation scheme that conveys data by changing, or modulating, the phase of a reference signal (the carrier wave).
Two common examples are binary phase-shift keying (BPSK) which uses two phases, and quadrature phase-shift keying (QPSK) which uses four phases, although any number of phases may be used.
In reaching 5.5 Mbit/s and the full-rate of 11 Mbit/s, QPSK is employed, but has to be coupled with complementary code keying.
www.wikipedia.org /wiki/Phase-shift_keying   (3610 words)

  
 Privateline.Com: GSM/PCS by John Scourias with comments by Tom Farley: RC Levine's comments on GMSK
GMSK uses a special waveform to achieve a gradual change in frequency when the two consecutive binary bits to be transmitted are 01 or 10.
GMSK was developed specifically for GSM by the COST (Council on Science and Technology, a scientific advisory group funded by CCITT and later ETSI).
The important thing about use of GMSK for GSM is that the power produced in an adjacent modulated carrier bandwidth (the 200 kHz section of spectrum next to the desired channel) is less than 1/2 percent of the desired signal power.
www.privateline.com /PCS/GSM07supplement.html   (1031 words)

  
 CommsDesign - Efficient GMSK Modulator Targets GSM Designs
Gaussian filtering: Assuming that the output of the Gaussian filter is sampled at N samples/symbol, the filtering operation involves filtering of 148 symbols/burst x N samples/symbol = 148N samples/burst.
In a traditional GMSK implementation, such as the one shown in Figure 1, bits to be transmitted are filtered through the Gaussian filter with impulse response g(t) and integrated to generate the instantaneous phase of the modulated signal.
Quantization errors in the Gaussian filter coefficients and filtering (accumulation) operation and generation of I and Q via cosine and sine computations are major sources of the inaccuracies.
www.hellosoft.com /resources/documents/abhijit.htm   (2339 words)

  
 GSM Security and Encryption
Public and private keys exist in pairs and ideally have the property that the private key may not be deduced from the public key, which allows the public key to be openly distributed.
The key length may alternately be examined by determining the number of hypothetical cracking machines required to decrypt a message in a given period of time.
The ciphering key is computed by applying the same random number (RAND) used in the authentication process to the ciphering key generating algorithm (A8) with the individual subscriber authentication key (Ki).
www.hackcanada.com /blackcrawl/cell/gsm/gsm-secur/gsm-secur.html   (4218 words)

  
 System for arranging and sharing shift register memory - Patent 4078258
As shown the normal data flow is from the output stage of the shift register to the A register, then along the D path to the N register, and then, bypassing the insert register, along the B C path to the B register and then into the input stage of the shift register.
The shift register is first loaded by a input operation with dummy codes from the data buss and then control codes are input into the shift register and written over the dummy codes.
The output from the shift register applied to lines 40 is also applied along lines 41 to the decode unit 42 which has its output applied along lines 43 to the control logic (not shown).
www.freepatentsonline.com /4078258.html   (10833 words)

  
 Read about VMSK at WorldVillage Encyclopedia. Research VMSK and learn about VMSK here!
VMSK, for Very Minimum Shift Keying modulation, is one of a growing class of digital
This claim is readily dismissed with the Nyquist-Shannon sampling theorem which states that for a receiver to be able to distinguish among data-dependent changes made to a signal at a given rate, the channel bandwidth must be at least one half that signaling rate.
The information in all these allegedly ultra-narrowband signals is actually conveyed in the very weak, very wideband spectral components that generally fall well below the noise floor of a spectrum analyzer.
encyclopedia.worldvillage.com /s/b/VMSK   (355 words)

  
 Synchronous receiver for minimum shift keying transmission - Patent 4942592
Minimum shift keying (MSK) is a frequency/phase modulation technique which is used to transmit digital data, i.e., binary 1's and 0's.
Referring to this figure, the transmitter's carrier frequency (w.sub.c) is shifted or "deviated" by a specified amount (dw) in one direction to transmit at binary 1, while the carrier frequency is deviated in the opposite direction for a binary 0.
A phase shifter 210 shifts the phase of the oscillator output signal by 90.degree..
www.freepatentsonline.com /4942592.html   (4990 words)

  
 Minimum shift keying - Patent Storm
A Minimum-Shift Keying (MSK) modulator is described, wherein a feedback scheme is used in combination with a precise frequency reference to enable the production of MSK modulation at the output of an off-the-shelf voltage controlled oscillator (VCO).
In the modulation and demodulation of a plurality of frequency separated channels on a radio frequency carrier by digitally coded speech or data, the speech or data is modulated on a digitally generated sub-carrier by quadrature phase shift keying and after conversion to analogue form the...
A continuous phase frequency shift keyed modulated signal with a modulation index of 0.5 is produced at the desired output...
www.patentstorm.us /class/375/305-Minimum_shift_keying.html   (2633 words)

  
 Bandwidth-Efficient Modulation
In other words, the Gaussian minimum shift keying waveform is usually less power-efficient than more traditional waveforms such as binary phase-shift keying and requires a more complex receiver, but this potential reduction in power efficiency and increase in receiver complexity could be rewarded with a very significant enhancement of bandwidth efficiency.
With Gaussian minimum shift keying, input bits with rectangular (+1, -1) representation are converted to Gaussian (bell-shaped) pulses by a Gaussian filter before further smoothing by a frequency modulator.
With Gaussian minimum shift keying, there are no well-defined phase transitions to detect for bit synchronization, and the energy from each bit is mixed with the energy from several other bits.
www.aero.org /publications/crosslink/winter2002/03.html   (2366 words)

  
 Modulation Basics
Gaussian minimum shift keying, the waveform that Aerospace proposed for the Advanced Extremely High Frequency program, is a form of continuous phase modulation.
Binary phase-shift keying takes each input bit individually and chooses one of two possible phases to represent that bit value—so for example, to send a "0," a phase of 0 degrees might be chosen, and to send a "1," a phase of 180 degrees might be chosen.
Frequency-shift keying has some attractive characteristics, but it generally does not use bandwidth very efficiently and is not suitable for applications where bandwidth efficiency is crucial.
www.aero.org /publications/crosslink/winter2002/03_sidebar2.html   (609 words)

  
 Robust Gmsk Demodulation Using Demodulator Diversity And Ber Estimation (SMEALSearch) - Pal,Rangaswamy,Giles,Debnath
This research investigates robust demodulation of Gaussian Minimum Shift Keying (GMSK) signals, using demodulator diversity and real-time bit-error-rate (BER) estimation.
GMSK is particularly important because of its use in prominent wireless standards around the world (GSM, DECT, CDPD, DCS1800, and PCS1900).
Various forms of GMSK demodulation are simulated, including the limiter discriminator and differential demodulator (i.e., twenty-five variations in all).
smealsearch.psu.edu /137944.html   (394 words)

  
 El afinar mínimo gaussian del movimiento
GMSK es un formulario espectral-eficiente de la modulación, pero necesita el nivel de una energía más alta que la opinión, movimiento de la cuadratura que afina (QSK) para comunicar confiablemente la misma cantidad de datos.
Si las formas gaussian no se traslapan, entonces el formulario de la modulación se llama 1-gmsk.
El movimiento mínimo gaussian que afina o GMSK es una clase de modulación contínua de la fase.
www.yotor.net /wiki/es/el/El%20afinar%20m%EDnimo%20gaussian%20del%20movimiento.htm   (273 words)

  
 baseband pulse shaping filter
In general, the MPSK (M'ary phase shift keying) spectrum consists of a main lobe representing the middle of the spectrum and various side lobes located on either side of the main lobe.
The shaped NRZ data using Gaussian pulse shaped filter are shown in Figure 10, and shaped NRZ data using new pulse shaping filter are shown in Figure 11.
Gaussian pulse shaping filter with bandwidth and time product (BT) = 0.5 and 0.7 is shown in Figures 8 and 9, respectively.
www.rfdesign.com /mag/radio_simulation_realization_baseband/index.html   (1464 words)

  
 GMSK Modem (MOD-96) - <%= company_name %> - Products
Employs a Gaussian Minimum Shift Keying (GMSK) modulation scheme.
GMSK modulation performance is similar to that of a G3RUH modem used on board all of the UoSAT-class spacecraft and is identical to that used on the AMRAD Oscar 27 spacecraft.
Modem is contained on a single, multi-layered printed circuit board without enclosure.
www.spacequest.com /mod96.asp   (225 words)

  
 etd-10212004-000946
A modulation method requiring continuous phase control of the carrier signal over the full 360 degree range is Gaussian Minimum Shift Keying (GMSK).
The frequency multiplier is a nonlinear circuit that shifts the frequency by *'N'.
The subtle part of this nonlinear operation is that the multiplier also multiplies the instantaneous phase of the phase shifter output signal by *'N', thus expanding the linear phase shift range to the required 360 degrees.
library.usask.ca /theses/available/etd-10212004-000946   (368 words)

  
 Radio-Electronics.Com :: Glossary of Cellular Telecommunications Terms [G-J]
It is a form of minimum shift keying (MSK) that is passed through a filter with a Gaussian curve to reduce its bandwidth.
The form of phase shift keying used for GSM cell phone transmissions.
An evolution of GSM system that uses packet data to provide a more efficient use of the available data capacity and thereby enables maximum data speeds of up to 115 kbps to be achieved.
www.radio-electronics.com /info/cellulartelecomms/cellular_glossary/cellularglossary_g.php   (619 words)

  
 SPONSORED TUTORIAL
Oqpsk modulation does not appear to be as well understood as, say, gaussian minimum shift keying (gmsk) modulation used in gsm.
The standard modulation used in digital communications systems is phase shift keying (psk), where a digital symbol is represented by phase states of a sinusoidal carrier.
One issue raised in the development of the ACeS test equipment was the correct generation of the offset quadrature phase shift keying (oqpsk) modulation.
www.neon.co.uk /campus/articles/racal/racal3.htm   (1373 words)

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