The need for larger capacities in long haul optical digital transmission lead to greater channel
density which can be achieved by wavelength division multiplexing and increasing the bit rate of each channel.
As data rates increases, certain phenomena such as dispersion began to show up as obstacles. At higher bit
rates beyond 2.5Gbps polarization mode dispersion (PMD) becomes a main factor in the degradation of the
transmission characteristics. PMD occurs when slightly different planes of light inside a fiber travel at slightly
different speeds and make it impossible to transmit data reliably at high speed in single mode fibers. PMD is
caused due to optical birefringence in the fiber due to which the two modes within a single mode fiber travel
with different group velocities and the random change of this birefringence along the fiber length results in
random coupling between the modes. This effect of PMD results in broadening of transmitted pulses that limit
the transmission capacity of the fiber. In high-speed optical communication systems working at data rates of
10Gbps and beyond, signal distortion caused by PMD is also a major limitation of the transmission distance.
This paper intends to analyze the performance of PMD compensation by optical compensation technique and
using DCF in a two channel WDM system. The analysis is done through eye diagrams from which the Q value
and bit error rate can be determined by simulating with OptSim5.3, which includes the latest simulation
algorithms to guarantee the highest possible accuracy and real world results
FUTURE TRENDS IN FIBER OPTICS COMMUNICATIONIJCI JOURNAL
Fiber optic systems are vital media transmission foundation for overall broadband systems. Wide data transfer capacity (bandwidth) signal transmission with low delay is a key prerequisite in present day applications. Optical fiber give broad and incomparable transmission transfer speed with insignificant expectations, and are currently the transmission medium of decision for long separation and high information rate transmission in media transmission systems. This paper gives a review of fiber optic communication system, including their key advances, and furthermore talks about their mechanical pattern towards the next generation.
Fiber type and corresponding optical transceiversAngelina Li
Fiber optic patch cable as the basic element of a network, transmits signals through strands of glass or plastic fiber. Fiber optic cables are available in multimode and single-mode fibers terminated with LC, SC, ST, LC, FC, MTRJ, E2000 connectors in simplex and duplex. The typical multimode fiber used in telecom or datacom applications has a core size of 50 or 62.5 microns. Single-mode fiber shrinks the core size down to 9 microns so that the light can only travel in one ray.
Experimental Study for the Different Methods of Generating Millimeter WavesIJERA Editor
In this paper a analytical comparison and experimental implementation of different methods used in generating a low phase noise millimeter wave signals is presented. Four techniques were experimented and compared, Multiplication, phase lock loop (PLL), Injection locking (IL), and Injection locking with phase lock loop (ILPLL). The comparison and experimental results of a laboratory discussed.
Massive multiple-input multiple-output (MIMO) systems are considered a promising solution to minimize multiuser interference (MUI) based on simple precoding techniques with a massive antenna array at a base station (BS). This paper presents a novel approach of beam division multiple access (BDMA) which BS transmit signals to multiusers at the same time via different beams based on hybrid beamforming and user-beam schedule. With the selection of users whose steering vectors are orthogonal to each other, interference between users is significantly improved. While, the efficiency spectrum of proposed scheme reaches to the performance of fully digital solutions, the multiuser interference is considerably reduced.
FUTURE TRENDS IN FIBER OPTICS COMMUNICATIONIJCI JOURNAL
Fiber optic systems are vital media transmission foundation for overall broadband systems. Wide data transfer capacity (bandwidth) signal transmission with low delay is a key prerequisite in present day applications. Optical fiber give broad and incomparable transmission transfer speed with insignificant expectations, and are currently the transmission medium of decision for long separation and high information rate transmission in media transmission systems. This paper gives a review of fiber optic communication system, including their key advances, and furthermore talks about their mechanical pattern towards the next generation.
Fiber type and corresponding optical transceiversAngelina Li
Fiber optic patch cable as the basic element of a network, transmits signals through strands of glass or plastic fiber. Fiber optic cables are available in multimode and single-mode fibers terminated with LC, SC, ST, LC, FC, MTRJ, E2000 connectors in simplex and duplex. The typical multimode fiber used in telecom or datacom applications has a core size of 50 or 62.5 microns. Single-mode fiber shrinks the core size down to 9 microns so that the light can only travel in one ray.
Experimental Study for the Different Methods of Generating Millimeter WavesIJERA Editor
In this paper a analytical comparison and experimental implementation of different methods used in generating a low phase noise millimeter wave signals is presented. Four techniques were experimented and compared, Multiplication, phase lock loop (PLL), Injection locking (IL), and Injection locking with phase lock loop (ILPLL). The comparison and experimental results of a laboratory discussed.
Massive multiple-input multiple-output (MIMO) systems are considered a promising solution to minimize multiuser interference (MUI) based on simple precoding techniques with a massive antenna array at a base station (BS). This paper presents a novel approach of beam division multiple access (BDMA) which BS transmit signals to multiusers at the same time via different beams based on hybrid beamforming and user-beam schedule. With the selection of users whose steering vectors are orthogonal to each other, interference between users is significantly improved. While, the efficiency spectrum of proposed scheme reaches to the performance of fully digital solutions, the multiuser interference is considerably reduced.
Fiber optics, which is the science of light transmission through very fine glass or plastic fibers,
continues to be used in more and more applications due to its inherent advantages over copper
conductors. The purpose of this article is to provide the non-technical reader with an overview of
these advantages, as well as the properties and applications of fiber optics.
View more of our white papers about fiber optics:
http://www.fibersystems.com/technical-resources/fiber-optic-whitepapers
This paper deals with different loss mechanisms within the single mode fiber (SMF) in optical fiber communication. A number of mechanisms are responsible for the signal attenuation within optical fibers. As the optical signal propagates over long stretch of fiber, it becomes attenuated because of absorption,
scattering, fiber bends by material impurities, and other effects. The transmission using high bandwidth
can handle vast amounts of information, which can be further improved by reduction in fiber losses,
increase in data rates and distances, and using appropriate operating wavelength in optical fiber communication. The recent development in the area of fiber optic communication as well as the advances in different fiber types and their properties such as attenuation or loss and bandwidth are also discussed in this paper. The performance improvement of the proposed different loss, such as Rayleigh scattering, Stimulated Brillouin Scattering (SBS), Stimulated Raman Scattering (SRS), and bending loss within the various loss mechanisms in fiber optic communication is shown through simulations.
EFFECT OF DUTY CYCLE ON ENERGY CONSUMPTION IN WIRELESS SENSOR NETWORKSIJCNC
Most studies define a common duty cycle value throughout the wireless sensor networks (WSNs) to
achieve synchronization among the nodes. On the other hand, a few studies proposed adaptation of the
duty cycle according to uniform traffic conditions to decrease the energy consumption and latency. In
this paper, the lifetime of the nodes based on overall energy consumption are estimated and the effect of
duty cycle on expected energy consumption is studied. The proposed scheme is compared with a standard
scheme and is shown to perform significantly better for sufficient node density.
Profile of Single Mode Fiber Coupler Combining with Bragg GratingTELKOMNIKA JOURNAL
This paper describes a numerical experiment of design and operation of a fiber coupler between
single mode fiber and fiber Bragg grating (FBG). Both components are coupled depending with optical
waveguide and source parameters. A characterization of fiber coupler is simulated by varying long grating
of 10 mm to 60 mm using transfer matrix method based on coupled mode equation. The wave peak,
transmission, and dispersion parameters are analyzed to determine the performance of the fiber coupler.
The transmission spectrum showed the wave peaks rise to any increase in the grating length on channel
1 and channel 2. Transmission on channel 1 and channel 2 decreased from the wavelength range of
1.45μm–1.55μm and rised in the range of 1,55μm–1,65μm for each increment in length of grating. The
dispersion showed the zero dispersion at specific wavelength for each increase in length of grating. This
component can be applied for controlling information signal in wide range communication.
Enhanced fractional frequency reuse approach for interference mitigation in f...journalBEEI
Small cell networks are expected to heavily be deployed in wireless communication networks due to it ability to enhance signals quality and spectrum utilisation. However, interference is posing a major threat to wireless communication especially cellular femtocell networks whereby its performance is degraded in dense deployment areas. For this reason, an enhanced fractional frequency reuse approach is proposed in this paper to mitigate the interference in femtocell networks. This is achieved by dividing the service area and frequency into three regions and three sets whereby each set is allocated different frequency set. The femtocell location is later obtained and assigned frequency in accordance to the region. The proposed approach helps in reducing the interference, boost the signal to interference plus noise (SINR), and enhance the throughput.
High Performance Data Bus Encoding Technique in DSM TechnologyIDES Editor
To increase the performance and reliability of
highly integrated circuits like DSP processors,
Microprocessors and SoCs, transistors sizes are continues to
scale towards Deep Submicron and Very Deep Submicron
dimensions . As more and more transistors are packed on the
chip to increase the functionality more metal layers are being
added to the integrated chips. Hence the performance of the
chips depends more on the performance of global interconnect
and on-chip busses than gate performance. The performance
of the global interconnects and on-chip data busses is limited
by switching activity, energy dissipation and noise such as
crosstalk, leakage, supply noise and process variations etc.
which are the side effects of the technology scaling. To increase
the performance of overall system it is necessary to control
and reduce these technology scaling effects on on-chip data
buses. One of the favorable techniques to increase the
efficiency of the data buses is to encode the data on the onchip
bus. Data encoding technique is the promising method to
increase the performance of the data bus and hence overall
system performance. Hence high performance data bus
encoding technique is propose which reduces switching
activity, transition energy dissipation, crosstalk and crosstalk
delay. The proposed method reduces the switching activity by
around 23%, energy dissipation by 46%, 6C, 5C and 4C type
crosstalk by around 89%, 73% and 31% respectively and
crosstalk delay by around 44% to 50% compare to unencoded
data.
Analysis on The Impact of Reflectance in Optical Fiber Linksijtsrd
An optical fiber link is a part of an optic fiber communication system. Other components of the optic fiber link include the transmitter, connectors, and the receiver. The optical fiber could be single-mode (for long distance transmission) or multi-mode (for short distance transmission). This paper however, majors on the impact of reflectance in the single-mode optical fiber. Reflectance is a hidden threat that increases Bit Error Rate, BER, (rate at which errors occur in transmission system) and reduces system performance if not monitored or controlled. Optical Time Domain Reflectometer (OTDR) was used to measure the reflectance in single-mode fiber. Events measurements in OTDR heavily depend on good reflectance. The OTDR was able to establish the reflectance in every portion of the fiber under test. An average reflectance level of -14.9275 dB of 1550 nm signal over the span length of 20.422 km was achieved which is within the acceptable standard range. Hence, good quality performance transmissions can be achieved along these routes. J. Ilouno | M. Awoji | J. Sani"Analysis on The Impact of Reflectance in Optical Fiber Links" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-2 | Issue-4 , June 2018, URL: http://www.ijtsrd.com/papers/ijtsrd14378.pdf http://www.ijtsrd.com/physics/other/14378/analysis-on-the-impact-of-reflectance-in-optical-fiber-links/j-ilouno
RECONFIGURABLE OPTICAL ADD AND DROP MULTIPLEXERS A REVIEWecijjournal
Optical multiplexing is the key function of a WDM network and reliable method for data transport networks. WDM networks configured as rings/mesh along with Optical Add-Drop Multiplexers supports added flexibility, simplicity and augment the spectral efficiency. Further enhancement achieved with Reconfigurable OADM architectures, growing briskly along with automatic network management, let the transport network to acclimatize with dynamically varying environment and flexibly respond to the transport network changes. It permits single or many wavelengths to be added and/or dropped from a
transport fiber without optical-to-electrical-to-optical domain translation. Presently ROADM technology
has revolutionized optical networking and an inseparable part of modern optical communication offering huge bandwidth for data transport at minimum expense. In this view the article presents comprehensive study for numerous generations of ROADM and their architecture and persistent development
Diversity combining is a technique in wireless network that uses multiple antenna system to improve the quality of radio signal. Mobile radio system suffers multipath propagation due to signal obstruction in the channel. A new hybridized diversity combining scheme consisting of Equal Gain Combining (EGC) and Maximal Ratio Combining (MRC) was proposed in this paper. Theperformance of the hybrid model was evaluated using Outage Probability (Pout) and Processing time (Pt) at different Signal-to-Noise Ratio (SNR) and Signal Paths (L=2,3) for 4-QAM and 8-QAM Modulation Schemes. A mathematical expression for the hybrid EGC-MRC was realized using the Probability Density Function (PDF) of the Nakagami fading channel. MATLAB R2015b software was used for the model simulation. The result shows that hybrid EGC-MRC outperforms the standalone EGC and MRC schemes by having lower Pout and Pt values. Hence, hybrid EGC-MRC exhibits enhanced potentials to mitigate multipath propagation at reduced system complexity.
A NEW HYBRID DIVERSITY COMBINING SCHEME FOR MOBILE RADIO COMMUNICATION SYSTEM...ijcsit
Diversity combining is a technique in wireless network that uses multiple antenna system to improve the quality of radio signal. Mobile radio system suffers multipath propagation due to signal obstruction in the channel. A new hybridized diversity combining scheme consisting of Equal Gain Combining (EGC) and Maximal Ratio Combining (MRC) was proposed in this paper. Theperformance of the hybrid model was evaluated using Outage Probability (Pout) and Processing time (Pt) at different Signal-to-Noise Ratio (SNR) and Signal Paths (L=2,3) for 4-QAM and 8-QAM Modulation Schemes. A mathematical expression for the hybrid EGC-MRC was realized using the Probability Density Function (PDF) of the Nakagami fading channel. MATLAB R2015b software was used for the model simulation. The result shows that hybrid EGC-MRC outperforms the standalone EGC and MRC schemes by having lower Pout and Pt values. Hence, hybrid EGC-MRC exhibits enhanced potentials to mitigate multipath propagation at reduced
system complexity.
Background/Objectives: The main aim of this research paper is to evaluate thedifferent linearly polarized
modes for two channel MDM passive optical network. Methods/Statistical Analysis: In this work mode division
multiplexing from 48 users. Three different combinations of linear polarized modes is tested for odd modes,
even modes and consecutive modes.System evaluated for 55 Km also on higher launched powers.Findings:
Results revealed that mode number 1,3 and 5 perform better and suffered from less mode crosstalk. However
even modes perform less effective than odd modes but better than mode number 1,2 and 3.Further 16 user for
each mode is splitted and 10 dB optimal power is found, beyond this power system performance degrated.LP 01
provide maximum quality factor and worst in case of LP 21 mode.
Background/Objectives: The main aim of this research paper is to evaluate thedifferent linearly polarized
modes for two channel MDM passive optical network. Methods/Statistical Analysis: In this work mode division
multiplexing from 48 users. Three different combinations of linear polarized modes is tested for odd modes,
even modes and consecutive modes.System evaluated for 55 Km also on higher launched powers.Findings:
Results revealed that mode number 1,3 and 5 perform better and suffered from less mode crosstalk. However
even modes perform less effective than odd modes but better than mode number 1,2 and 3.Further 16 user for
each mode is splitted and 10 dB optimal power is found, beyond this power system performance degrated.LP 01
provide maximum quality factor and worst in case of LP 21 mode.
Study of Polarization Mode Dispersion in the Optical Digital Connection to Hi...ijcnac
Polarization Mode Dispersion (PMD) is a factor which limits the bit rate of the optical transmissions. The PMD is such an effect which is time broadening due to the dependence of the group velocity to the signal polarization. The deformation effects of the impulses become considerable from 40 Gb/s. This paper, we reviews the degrade PMD effect in the telecommunications optical connections to high bit rate, due to the evolution of quality factor (Q) according to the fiber length, bit rate and PMD coefficient , well as the impact PMD on the degree of polarization and electrical power, we discuss also the representation of the polarization state and PMD vector on the Poincare sphere.
The seriousness of the health hazards due to radiation from the Cell towers has not been realized among the common man. Cell operators continue to claim that there are no health issues. Even organizations like WHO, ICNIRP, FCC, etc. have not recommended stricter safe radiation guidelines, whereas several countries have adopted radiation norms, which are 1/100th to 1/1000th of these values based on their studies. Cell phone industry is becoming another cigarette industry, which kept claiming that smoking is not harmful and now there are millions of people around the world who have suffered from smoking. In fact, cell phone/tower radiation is worse than smoking; as one cannot see it or smell it, and its effect on health is noted after a long period of exposure. Therefore, majority of people tend to have casualness towards personal protection. Unfortunately, ignorance and non-awareness adds to this misery and all of us are absorbing this slow poison unknowingly. Even if people are aware of the radiation hazard.
So this paper was concern with practical measurement of cell tower radiation and QoS along with realization of compliance distance for various antenna gain and bands. It was observed that operators were able to manage radiation level 1/100 to 1/1000 below the recommended value while maintaining QoS. So, so radiation norms can be further strengthened i.e. recommended power density at compliance distance may be f/20000 or less then it. It was observed that compliance distance for 6 carriers with 18dBi antenna gain and 43dBm EIRP was near about 12 meters from the tower and for 36 carriers this value reaches to 57.5 meter. It was also observed that compliance distance varies with antenna gain, transmitting power, frequency etc
Fiber optics, which is the science of light transmission through very fine glass or plastic fibers,
continues to be used in more and more applications due to its inherent advantages over copper
conductors. The purpose of this article is to provide the non-technical reader with an overview of
these advantages, as well as the properties and applications of fiber optics.
View more of our white papers about fiber optics:
http://www.fibersystems.com/technical-resources/fiber-optic-whitepapers
This paper deals with different loss mechanisms within the single mode fiber (SMF) in optical fiber communication. A number of mechanisms are responsible for the signal attenuation within optical fibers. As the optical signal propagates over long stretch of fiber, it becomes attenuated because of absorption,
scattering, fiber bends by material impurities, and other effects. The transmission using high bandwidth
can handle vast amounts of information, which can be further improved by reduction in fiber losses,
increase in data rates and distances, and using appropriate operating wavelength in optical fiber communication. The recent development in the area of fiber optic communication as well as the advances in different fiber types and their properties such as attenuation or loss and bandwidth are also discussed in this paper. The performance improvement of the proposed different loss, such as Rayleigh scattering, Stimulated Brillouin Scattering (SBS), Stimulated Raman Scattering (SRS), and bending loss within the various loss mechanisms in fiber optic communication is shown through simulations.
EFFECT OF DUTY CYCLE ON ENERGY CONSUMPTION IN WIRELESS SENSOR NETWORKSIJCNC
Most studies define a common duty cycle value throughout the wireless sensor networks (WSNs) to
achieve synchronization among the nodes. On the other hand, a few studies proposed adaptation of the
duty cycle according to uniform traffic conditions to decrease the energy consumption and latency. In
this paper, the lifetime of the nodes based on overall energy consumption are estimated and the effect of
duty cycle on expected energy consumption is studied. The proposed scheme is compared with a standard
scheme and is shown to perform significantly better for sufficient node density.
Profile of Single Mode Fiber Coupler Combining with Bragg GratingTELKOMNIKA JOURNAL
This paper describes a numerical experiment of design and operation of a fiber coupler between
single mode fiber and fiber Bragg grating (FBG). Both components are coupled depending with optical
waveguide and source parameters. A characterization of fiber coupler is simulated by varying long grating
of 10 mm to 60 mm using transfer matrix method based on coupled mode equation. The wave peak,
transmission, and dispersion parameters are analyzed to determine the performance of the fiber coupler.
The transmission spectrum showed the wave peaks rise to any increase in the grating length on channel
1 and channel 2. Transmission on channel 1 and channel 2 decreased from the wavelength range of
1.45μm–1.55μm and rised in the range of 1,55μm–1,65μm for each increment in length of grating. The
dispersion showed the zero dispersion at specific wavelength for each increase in length of grating. This
component can be applied for controlling information signal in wide range communication.
Enhanced fractional frequency reuse approach for interference mitigation in f...journalBEEI
Small cell networks are expected to heavily be deployed in wireless communication networks due to it ability to enhance signals quality and spectrum utilisation. However, interference is posing a major threat to wireless communication especially cellular femtocell networks whereby its performance is degraded in dense deployment areas. For this reason, an enhanced fractional frequency reuse approach is proposed in this paper to mitigate the interference in femtocell networks. This is achieved by dividing the service area and frequency into three regions and three sets whereby each set is allocated different frequency set. The femtocell location is later obtained and assigned frequency in accordance to the region. The proposed approach helps in reducing the interference, boost the signal to interference plus noise (SINR), and enhance the throughput.
High Performance Data Bus Encoding Technique in DSM TechnologyIDES Editor
To increase the performance and reliability of
highly integrated circuits like DSP processors,
Microprocessors and SoCs, transistors sizes are continues to
scale towards Deep Submicron and Very Deep Submicron
dimensions . As more and more transistors are packed on the
chip to increase the functionality more metal layers are being
added to the integrated chips. Hence the performance of the
chips depends more on the performance of global interconnect
and on-chip busses than gate performance. The performance
of the global interconnects and on-chip data busses is limited
by switching activity, energy dissipation and noise such as
crosstalk, leakage, supply noise and process variations etc.
which are the side effects of the technology scaling. To increase
the performance of overall system it is necessary to control
and reduce these technology scaling effects on on-chip data
buses. One of the favorable techniques to increase the
efficiency of the data buses is to encode the data on the onchip
bus. Data encoding technique is the promising method to
increase the performance of the data bus and hence overall
system performance. Hence high performance data bus
encoding technique is propose which reduces switching
activity, transition energy dissipation, crosstalk and crosstalk
delay. The proposed method reduces the switching activity by
around 23%, energy dissipation by 46%, 6C, 5C and 4C type
crosstalk by around 89%, 73% and 31% respectively and
crosstalk delay by around 44% to 50% compare to unencoded
data.
Analysis on The Impact of Reflectance in Optical Fiber Linksijtsrd
An optical fiber link is a part of an optic fiber communication system. Other components of the optic fiber link include the transmitter, connectors, and the receiver. The optical fiber could be single-mode (for long distance transmission) or multi-mode (for short distance transmission). This paper however, majors on the impact of reflectance in the single-mode optical fiber. Reflectance is a hidden threat that increases Bit Error Rate, BER, (rate at which errors occur in transmission system) and reduces system performance if not monitored or controlled. Optical Time Domain Reflectometer (OTDR) was used to measure the reflectance in single-mode fiber. Events measurements in OTDR heavily depend on good reflectance. The OTDR was able to establish the reflectance in every portion of the fiber under test. An average reflectance level of -14.9275 dB of 1550 nm signal over the span length of 20.422 km was achieved which is within the acceptable standard range. Hence, good quality performance transmissions can be achieved along these routes. J. Ilouno | M. Awoji | J. Sani"Analysis on The Impact of Reflectance in Optical Fiber Links" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-2 | Issue-4 , June 2018, URL: http://www.ijtsrd.com/papers/ijtsrd14378.pdf http://www.ijtsrd.com/physics/other/14378/analysis-on-the-impact-of-reflectance-in-optical-fiber-links/j-ilouno
RECONFIGURABLE OPTICAL ADD AND DROP MULTIPLEXERS A REVIEWecijjournal
Optical multiplexing is the key function of a WDM network and reliable method for data transport networks. WDM networks configured as rings/mesh along with Optical Add-Drop Multiplexers supports added flexibility, simplicity and augment the spectral efficiency. Further enhancement achieved with Reconfigurable OADM architectures, growing briskly along with automatic network management, let the transport network to acclimatize with dynamically varying environment and flexibly respond to the transport network changes. It permits single or many wavelengths to be added and/or dropped from a
transport fiber without optical-to-electrical-to-optical domain translation. Presently ROADM technology
has revolutionized optical networking and an inseparable part of modern optical communication offering huge bandwidth for data transport at minimum expense. In this view the article presents comprehensive study for numerous generations of ROADM and their architecture and persistent development
Diversity combining is a technique in wireless network that uses multiple antenna system to improve the quality of radio signal. Mobile radio system suffers multipath propagation due to signal obstruction in the channel. A new hybridized diversity combining scheme consisting of Equal Gain Combining (EGC) and Maximal Ratio Combining (MRC) was proposed in this paper. Theperformance of the hybrid model was evaluated using Outage Probability (Pout) and Processing time (Pt) at different Signal-to-Noise Ratio (SNR) and Signal Paths (L=2,3) for 4-QAM and 8-QAM Modulation Schemes. A mathematical expression for the hybrid EGC-MRC was realized using the Probability Density Function (PDF) of the Nakagami fading channel. MATLAB R2015b software was used for the model simulation. The result shows that hybrid EGC-MRC outperforms the standalone EGC and MRC schemes by having lower Pout and Pt values. Hence, hybrid EGC-MRC exhibits enhanced potentials to mitigate multipath propagation at reduced system complexity.
A NEW HYBRID DIVERSITY COMBINING SCHEME FOR MOBILE RADIO COMMUNICATION SYSTEM...ijcsit
Diversity combining is a technique in wireless network that uses multiple antenna system to improve the quality of radio signal. Mobile radio system suffers multipath propagation due to signal obstruction in the channel. A new hybridized diversity combining scheme consisting of Equal Gain Combining (EGC) and Maximal Ratio Combining (MRC) was proposed in this paper. Theperformance of the hybrid model was evaluated using Outage Probability (Pout) and Processing time (Pt) at different Signal-to-Noise Ratio (SNR) and Signal Paths (L=2,3) for 4-QAM and 8-QAM Modulation Schemes. A mathematical expression for the hybrid EGC-MRC was realized using the Probability Density Function (PDF) of the Nakagami fading channel. MATLAB R2015b software was used for the model simulation. The result shows that hybrid EGC-MRC outperforms the standalone EGC and MRC schemes by having lower Pout and Pt values. Hence, hybrid EGC-MRC exhibits enhanced potentials to mitigate multipath propagation at reduced
system complexity.
Background/Objectives: The main aim of this research paper is to evaluate thedifferent linearly polarized
modes for two channel MDM passive optical network. Methods/Statistical Analysis: In this work mode division
multiplexing from 48 users. Three different combinations of linear polarized modes is tested for odd modes,
even modes and consecutive modes.System evaluated for 55 Km also on higher launched powers.Findings:
Results revealed that mode number 1,3 and 5 perform better and suffered from less mode crosstalk. However
even modes perform less effective than odd modes but better than mode number 1,2 and 3.Further 16 user for
each mode is splitted and 10 dB optimal power is found, beyond this power system performance degrated.LP 01
provide maximum quality factor and worst in case of LP 21 mode.
Background/Objectives: The main aim of this research paper is to evaluate thedifferent linearly polarized
modes for two channel MDM passive optical network. Methods/Statistical Analysis: In this work mode division
multiplexing from 48 users. Three different combinations of linear polarized modes is tested for odd modes,
even modes and consecutive modes.System evaluated for 55 Km also on higher launched powers.Findings:
Results revealed that mode number 1,3 and 5 perform better and suffered from less mode crosstalk. However
even modes perform less effective than odd modes but better than mode number 1,2 and 3.Further 16 user for
each mode is splitted and 10 dB optimal power is found, beyond this power system performance degrated.LP 01
provide maximum quality factor and worst in case of LP 21 mode.
Study of Polarization Mode Dispersion in the Optical Digital Connection to Hi...ijcnac
Polarization Mode Dispersion (PMD) is a factor which limits the bit rate of the optical transmissions. The PMD is such an effect which is time broadening due to the dependence of the group velocity to the signal polarization. The deformation effects of the impulses become considerable from 40 Gb/s. This paper, we reviews the degrade PMD effect in the telecommunications optical connections to high bit rate, due to the evolution of quality factor (Q) according to the fiber length, bit rate and PMD coefficient , well as the impact PMD on the degree of polarization and electrical power, we discuss also the representation of the polarization state and PMD vector on the Poincare sphere.
The seriousness of the health hazards due to radiation from the Cell towers has not been realized among the common man. Cell operators continue to claim that there are no health issues. Even organizations like WHO, ICNIRP, FCC, etc. have not recommended stricter safe radiation guidelines, whereas several countries have adopted radiation norms, which are 1/100th to 1/1000th of these values based on their studies. Cell phone industry is becoming another cigarette industry, which kept claiming that smoking is not harmful and now there are millions of people around the world who have suffered from smoking. In fact, cell phone/tower radiation is worse than smoking; as one cannot see it or smell it, and its effect on health is noted after a long period of exposure. Therefore, majority of people tend to have casualness towards personal protection. Unfortunately, ignorance and non-awareness adds to this misery and all of us are absorbing this slow poison unknowingly. Even if people are aware of the radiation hazard.
So this paper was concern with practical measurement of cell tower radiation and QoS along with realization of compliance distance for various antenna gain and bands. It was observed that operators were able to manage radiation level 1/100 to 1/1000 below the recommended value while maintaining QoS. So, so radiation norms can be further strengthened i.e. recommended power density at compliance distance may be f/20000 or less then it. It was observed that compliance distance for 6 carriers with 18dBi antenna gain and 43dBm EIRP was near about 12 meters from the tower and for 36 carriers this value reaches to 57.5 meter. It was also observed that compliance distance varies with antenna gain, transmitting power, frequency etc
The Effect of PMD (Polarization Mode Dispersion) the Fibers of New and Old In...inventionjournals
This is a study conducted in a laboratory at the university as a simulation to see the effect of new fiber PMD for different distances. This is done to compare the performance of the digital system with optical fiber WDM. In this simulation are not included remission, chromatic dispersion and nonlinear effects. In this way all of the signal distortions caused only by different combinations of PDM. Polarization effects are very important in communications systems with optical fiber. Optical fiber that is used mainly during the simulation is a standard single mode fiber (SSMF).
Performance Analysis of Dispersion Compensation in Long Haul Optical Fiber u...theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
In this work, high-speed transmission over the long-haul optical channel using orthogonal frequency division multiplexing (OFDM) was investigated. Furthermore, we recommend mixing polarization division multiplexing (PDM) with coherent OFDM (CO-OFDM) and quadrature amplitude modulation (16-QAM) to improve spectral efficiency (SE) while transmitting over a wavelength division multiplexing (WDM) system.
An 800 Gb/s WDM PDM-CO-OFDM-16QAM transmission system with various channel spacing of 100 GHz, 50 GHz, and 25 GHz is examined utilizing the OptiSystem (2021) version 18.0 software package over ten spans of 60 km standard single-mode fiber (SSMF). Different channel spacing WDM systems have been compared in terms of performance and SE. The results reveal that the WDM system with 100 GHz channel spacing has a longer transmission range and needs minimal optical signal to noise ratio (OSNR) at the reception. The 25 GHz channel spacing WDM system exceeds the others in terms of SE. Further, the effect of ultra-low loss and large effective area fiber in lowering span loss and nonlinear effects for
25 GHz channel spacing WDM system is investigated. The findings show that the system performance with the new fiber outperforms the SSMF.
The acceptable bit error rate (BER) for this study is 0.033 (20% concatenated forward error correction (FEC) threshold).
Empirical analysis of polarization division multiplexing-dense wavelength di...IJECEIAES
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Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
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1. IOSR Journal of Electronics and Communication Engineering (IOSR-JECE)
e-ISSN: 2278-2834,p- ISSN: 2278-8735.Volume 6, Issue 1 (May. - Jun. 2013), PP 24-29
www.iosrjournals.org
www.iosrjournals.org 24 | Page
Comparison of PMD Compensation in WDM Systems
Anju Kochumman1
, Lakshmy G.B.2
1
(PG Scholar, Dept. of Electronics & Communication Engg., TKM Institute of Technology, Kerala, India)
2
(Asst.Professor, Dept. of Electronics & Communication Engg., TKM Institute of Technology, Kerala, India)
Abstract: The need for larger capacities in long haul optical digital transmission lead to greater channel
density which can be achieved by wavelength division multiplexing and increasing the bit rate of each channel.
As data rates increases, certain phenomena such as dispersion began to show up as obstacles. At higher bit
rates beyond 2.5Gbps polarization mode dispersion (PMD) becomes a main factor in the degradation of the
transmission characteristics. PMD occurs when slightly different planes of light inside a fiber travel at slightly
different speeds and make it impossible to transmit data reliably at high speed in single mode fibers. PMD is
caused due to optical birefringence in the fiber due to which the two modes within a single mode fiber travel
with different group velocities and the random change of this birefringence along the fiber length results in
random coupling between the modes. This effect of PMD results in broadening of transmitted pulses that limit
the transmission capacity of the fiber. In high-speed optical communication systems working at data rates of
10Gbps and beyond, signal distortion caused by PMD is also a major limitation of the transmission distance.
This paper intends to analyze the performance of PMD compensation by optical compensation technique and
using DCF in a two channel WDM system. The analysis is done through eye diagrams from which the Q value
and bit error rate can be determined by simulating with OptSim5.3, which includes the latest simulation
algorithms to guarantee the highest possible accuracy and real world results.
Keywords– Birefringence, Data rate, Deterministic Differential Group Delay (DDGD), Dispersion
compensating fibers (DCFs) Polarization Mode Dispersion (PMD Principal State of Polarization (PSP), Q
value.
I. INTRODUCTION
Optical fiber communication plays a vital role in the development of high quality and high-speed
telecommunication systems. Fiber optic communications is a way of exchanging the information between two
places by sending the light signal through the optical fiber cable. Fiber optic communication brought the
revolutionary change in the telecommunication industry and played a major role in the advent of information
age. In the twenty first century, its advantages over electrical transmission cause the replacement of copper wire
with the optical fiber in the communication system. Now the optical fiber is the most common type of channel
used in communication system, but the other types of waveguides are also used within the communication
system. Today, optical fibers are not only used in telecommunication links but also used in the Internet and local
area networks (LAN) to achieve high signaling rates. The core advantages of optical fiber such as low loss,
which allows long distances between amplifiers and its high data carrying capacity as that of thousands of
electrical links would be required to carry that much data. Also no crosstalk introduces in optical fibers running
alongside each other for long distances as introduces in some types of electrical transmission lines.
The needs for larger capacities in long haul optical transmission lead to greater channel density
achieved by wavelength division multiplexing and increasing the bit rate for each channel. As the number of
channels and data rates increases, certain phenomena such as dispersion began to show up as obstacles. The
optical fiber has some inherent properties like birefringence, which leads to what is called polarization mode
dispersion (PMD). PMD effects are linear electromagnetic propagation phenomena occurring in so-called
„„single-mode‟‟ fibers. Despite their name, these fibers support two modes of propagation distinguished by their
polarization. Because of optical birefringence in the fiber, the two modes travel with different group velocities
and the random change of this birefringence along the fiber length results in random coupling between the
modes. The resulting PMD phenomena lead to pulse distortion and system impairments that limit the
transmission capacity of the fiber.
Polarization Mode Dispersion which is a time varying quantity is a serious problem that limits
distances and data rates in a single-mode optical fiber system. In high-speed optical communication systems
working at data rates of 10Gbps and beyond, signal distortion caused by polarization mode dispersion (PMD) is
a major limitation of the transmission distance. This leads to degradation in system performance. Especially in
upgrading of existing transmission lines, high PMD of „old‟ fibers is a serious problem. The PMD of installed
fibers fluctuates with time due to environmental influences, for example changes in temperature and stress.
Therefore, adaptive PMD compensation during system operation is indispensable.
2. Comparison of PMD Compensation in WDM Systems
www.iosrjournals.org 25 | Page
In general, the effect of PMD on an optical fiber communication link at different bit rates shows that it
causes several undesirable effects and it can be compensated through various compensation techniques. The
goal of this work is to analyze the effect Polarization Mode Dispersion compensation in a two channel WDM
system.
Here the effect of PMD compensation method is also proposed by which the degradation due to PMD
can be mitigated to a certain extent. The basic principle of optical compensation method is to split the optical
signal that exits from the optical fiber into two branches and sent to two polarizers which are complementary to
each other to obtain two polarization states. A suitable delay is provided to one of the polarization states and no
delay to the other state. Finally the two signals are added and as a result the two components experience a
differential delay. This differential delay cancels the differential group delay caused due to the effect of PMD.
Also the effect PMD compensation using dispersion compensating fibers in the post compensation mode is also
analyzed.
II. SYSTEM MODELING
Polarization mode dispersion is a physical phenomenon in optical fibers that causes light pulses to
spread in time. In high speed transmission systems beyond 2.5 Gbps increase in PMD causes the broadening of
pulses and hence adjacent pulses overlap and interfere with each other causing intersymbol interference
(ISI).Thus the effect of PMD severely degrades the system performance. The cause of PMD is birefringence
which can be due to geometrical variations in concentricity or ellipticity of fiber core or cladding during fiber
manufacture or due to stress on fiber because of pressure or temperature variations. Thus PMD is varying
randomly along the fiber length and therefore the effect of PMD can be reduced by introducing better fiber
manufacturing techniques or by compensating for PMD effects. Compensation can be achieved by electronic
equalization or by using dispersion compensating fibers or by optical equalization. Electronic compensation is
not sensitive to the phase and polarization information of the received signal and also it is bit rate dependent so
optical compensation is advantageous compared to electronic compensation. Therefore in this work an optical
compensation method is proposed to compensate for the effect of PMD.
2.1 Basic Block Diagram
The block diagram of the work is shown in the Figure.1and 2. It describes the basic components used
for the analysis of the effect of PMD compensation.
Figure 1: Block diagram for optical PMD compensation
Figure 2: Block diagram for PMD compensation using DCFs
In Figure 1 the optical compensation technique of using an emulator and a deterministic differential
group delay is analyzed. An emulator is used after the fiber link to recreate the behavior of an optical field fiber
in the laboratory. In Figure 2 the compensation using DCF is analyzed. Depending upon the position of placing
the DCF it can be of two types-pre compensation and post compensation. In pre-compensation the DCF is
placed before the fiber and in post-compensation technique the DCF is placed after the fiber. In this paper the
post-compensation technique is analyzed which is more efficient than the pre-compensation technique.
2.2 Simulation Block Diagram
The simulation is done in OptSim which is one of the costliest simulation software used for optical
communication. The below setup shown in Figure 3 simulates PMD effects with and without compensation. The
compensation is done by using a Deterministic Differential Group Delay. The effect can be analyzed through
eye diagrams and Q estimator.
3. Comparison of PMD Compensation in WDM Systems
www.iosrjournals.org 26 | Page
Figure 3: OptSim layout to analyze PMD compensation in two channel WDM using optical
compensation
Figure 4: OptSim layout to analyze PMD compensation in two channel WDM using post-DCF
Above figures shows a two wavelength WDM system capable of transmitting 20Gbps data consisting
of two transmitters and two receivers. The transmitters and receivers sections are connected by the dispersive
fiber link. The transmitter section consists of data source, modulator driver, laser source and modulator. Each
data source produces a pseudorandom sequence of bits at a rate of 10Gbps. So a 20 Gbps data can be send a
time with two sources along the single fiber channel The output of data source is given to modulator driver
which produces a NRZ (Non return to zero) format pulse train. The transmitted signal is formed by modulating
the light carrier by the NRZ data source. The light carrier is generated by Lorentzian laser source at the 1548
and 1552 nm wavelength. The light can be modulated by the input signal by passing through the amplitude
modulator. Amplitude modulator modulates the signal. Then the signal is passed through the fiber channel of
100km. As the signal travels through the fiber the effect of PMD affects the transmitted signal. For laboratory
setup in order to recreate the time varying effect of PMD an emulator is used. The emulator rotates the state of
polarization which in turn produces the differential group delay and hence the pulse broadens and signal
degrades. The distorted signal is received by the receiver and is analyzed through eye diagrams. For analyzing
the optical compensation shown in Figure 3, the signal emulated by the emulator is passed through a
deterministic differential group delay element which splits the signal into two and provides a determined delay
to one of the signal. This delay provided negates the distorted signal through the emulator and thus
compensation of PMD is achieved which can be seen from the eye diagrams. Figure 4 shows the OptSim layout
for analyzing the PMD compensation using post-DCF, where a suitable length of DCF is selected based on the
design rule equation:
= 0 (1)
4. Comparison of PMD Compensation in WDM Systems
www.iosrjournals.org 27 | Page
where , , , are the length and dispersion coefficient of the fiber and DCF respectively.
III. SIMULATION RESULTS
The effect of PMD compensation using an optical compensation technique and dispersion
compensating fiber in a WD|M is simulated using OptSim 5.3. The effect is analyzed through various eye
diagrams by performing parametric run. A parametric run is performed to simulate the time varying property of
the emulator. The eye diagrams give the Q values at each run from which the results can be interpreted. The
results of the simulations are shown below.
Figure 5: Eye diagram at run 1 showing a Q value of 13.068 dB for optical compensation
Figure 6: Eye diagram at run 3 showing a Q value of 13.2893 dB for optical compensation
Figure 7: Eye diagram at run 5 showing a Q value of 12.924 dB for optical compensation
5. Comparison of PMD Compensation in WDM Systems
www.iosrjournals.org 28 | Page
Figure 8: Eye diagram at run 1 showing a Q value of 8.976 dB for DCF
Figure 9: Eye diagram at run 3 showing a Q value of 9.191dB for DCF
Figure 10: Eye diagram at run 5 showing a Q value of 8.940dB for DCF
Figures 5 to 7 shows the effect of optical compensation and Figures 8 to 10 shows the effect of
compensation using post-DCF detected at one of the receivers. The two techniques can be compared by
analyzing the Q values of the obtained results which shows a higher Q value for optical compensation
technique.
The comparison of the optical compensation technique and that using post-DCF is outlined in the
figure below.
6. Comparison of PMD Compensation in WDM Systems
www.iosrjournals.org 29 | Page
Figure 11: comparison of PMD compensation using optical compensation and DCF
IV. CONCLUSION
The paper is based on the performance analysis of an optical compensation of polarization mode
dispersion which is a time varying quantity which causes a serious problem that limits distances and data rates
in a single-mode optical fiber system. The time varying property of polarization mode dispersion in a fiber link
is analyzed through various eye diagrams by parametric run in OptSim simulation. An optical compensation
method by which the effect of PMD can be mitigated is shown as an increase in Q value and decrease in BER
from the eye diagram of the simulation. The results show that optical compensation technique is suitable for
PMD compensation in WDM systems compared to dispersion compensating fibers.
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