Presentation of the paper "Optimizing the Number of Samples for Multi-Channel Spectrum Sensing" at the IEEE International Conference on Communications (IEEE ICC 2015)
Advancements in the Real-Time Simulation of Large Active Distribution Systems...OPAL-RT TECHNOLOGIES
This document discusses how real-time simulation technologies can help test phasor measurement units (PMUs) and PMU applications. It outlines different solvers for real-time digital simulators including real-time phasor simulation and electromagnetic transient simulation. It also discusses communication protocols supported by real-time simulators and gives examples of how utilities and researchers are using real-time simulators to develop and test PMUs, including simulating large distribution systems of over 750 nodes.
This document analyzes the capacity-based performance of optimal antenna selection for an 8x8 MIMO system. It simulates optimal antenna selection and finds that selecting 4 antennas provides channel capacity close to using all 8 antennas. The highest capacity of 44bps is achieved with 8 antennas selected. The capacity remains constant up to 18dB, 16dB and 12dB for antenna selection factors of 7, 6 and 5, respectively. For factors 1-4, capacity increases with SNR. For fading channels, 4 antenna selection authorizes channel capacity similar to using all 8 antennas in 8x8 MIMO.
This document contains the agenda for a seminar on electromagnetic waves, antennas, wireless transmission parameters and calculations, narrowband transmission, data rates, and a wireless lab. The topics covered include Maxwell's equations, antenna types such as monopole, dipole and parabolic, the Marconi equation, RF power loss, EIRP, RSS, SNR, modulation techniques, wireless standards such as 802.11a/b/g/n/ac, and configuring devices in a wireless lab including access points, wireless routers, and security settings.
JT@UCSB - On-Demand Data Streaming from Sensor Nodes and A quick overview of ...Jonas Traub
This slide set was presented at UCSB on Sep. 30, 2017.
The talk covers an extended version of the slides from SoCC 2017 plus a quick overview of Apache Flink.
This project implemented a wideband spectrum sensing algorithm using a software-defined radio to detect active signals in the electromagnetic spectrum around SUNY Oswego. The algorithm used hypothesis testing on received signals to identify center frequencies and bandwidths of signals like LTE, aeronautical radio and Earth-space communications. Testing showed the algorithm could accurately detect signals in noise and identify occupied portions of the spectrum between 88-90 MHz and others. Future work could involve networking multiple SDRs to provide real-time spectrum analysis across a wider area.
The document discusses an enhanced multimedia search algorithm called "Time series Active Search Algorithm" that uses feature vectors and histogram pruning to enable faster and more efficient searching of audio and video queries from large stored datasets. The algorithm extracts feature vectors from query and stored signals, classifies the vectors, obtains histograms, compares histograms using a threshold, and notifies of similarities. Experimental results found the algorithm reduced matches to over 1/291 for video and 1/501 for audio, making search very fast and reasonably robust even with noise and compression.
Performance Analysis of Fading Channels on Cooperative Mode Spectrum Sensing ...ijtsrd
Spectrum sensing is the main feature of cognitive radio technology. Spectrum sensing gives an idea of detecting the presence of the primary users in a licensed spectrum. The sensing of radio spectrum is an essential problem in cognitive radio CR networks, where secondary users SUs need to detect the presence of primary users PUs before they use the spectrum allocated to PUs. The detection of primary user status and the spectrum sensing are the major issues in cognitive radio systems. We employ one of the simplest and most efficient Spectrum Sensing technique, the cooperative spectrum sensing with three different digital modulation techniques BPSK, QPSK, 16 QAM. In this paper, we analyze the performance of the cooperative spectrum sensing technique with BPSK, QPSK, 16 QAM modulation techniques over Rayleigh fading Channel. Further, we analyze the performance and BER Bit Error Rate of cooperative spectrum sensing under Rayleigh fading and AWGN channels. The investigation and analysis on cooperative spectrum sensing with above digital modulation techniques can be utilized for future reference of spectrum sensing in the CR networks over AWGN and Rayleigh fading channels. Sangram Singh | Rashmi Raj "Performance Analysis of Fading Channels on Cooperative Mode Spectrum Sensing Technique for Cognitive Radio" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-4 | Issue-3 , April 2020, URL: https://www.ijtsrd.com/papers/ijtsrd30338.pdf Paper Url :https://www.ijtsrd.com/engineering/electronics-and-communication-engineering/30338/performance-analysis-of-fading-channels-on-cooperative-mode-spectrum-sensing-technique-for-cognitive-radio/sangram-singh
Advancements in the Real-Time Simulation of Large Active Distribution Systems...OPAL-RT TECHNOLOGIES
This document discusses how real-time simulation technologies can help test phasor measurement units (PMUs) and PMU applications. It outlines different solvers for real-time digital simulators including real-time phasor simulation and electromagnetic transient simulation. It also discusses communication protocols supported by real-time simulators and gives examples of how utilities and researchers are using real-time simulators to develop and test PMUs, including simulating large distribution systems of over 750 nodes.
This document analyzes the capacity-based performance of optimal antenna selection for an 8x8 MIMO system. It simulates optimal antenna selection and finds that selecting 4 antennas provides channel capacity close to using all 8 antennas. The highest capacity of 44bps is achieved with 8 antennas selected. The capacity remains constant up to 18dB, 16dB and 12dB for antenna selection factors of 7, 6 and 5, respectively. For factors 1-4, capacity increases with SNR. For fading channels, 4 antenna selection authorizes channel capacity similar to using all 8 antennas in 8x8 MIMO.
This document contains the agenda for a seminar on electromagnetic waves, antennas, wireless transmission parameters and calculations, narrowband transmission, data rates, and a wireless lab. The topics covered include Maxwell's equations, antenna types such as monopole, dipole and parabolic, the Marconi equation, RF power loss, EIRP, RSS, SNR, modulation techniques, wireless standards such as 802.11a/b/g/n/ac, and configuring devices in a wireless lab including access points, wireless routers, and security settings.
JT@UCSB - On-Demand Data Streaming from Sensor Nodes and A quick overview of ...Jonas Traub
This slide set was presented at UCSB on Sep. 30, 2017.
The talk covers an extended version of the slides from SoCC 2017 plus a quick overview of Apache Flink.
This project implemented a wideband spectrum sensing algorithm using a software-defined radio to detect active signals in the electromagnetic spectrum around SUNY Oswego. The algorithm used hypothesis testing on received signals to identify center frequencies and bandwidths of signals like LTE, aeronautical radio and Earth-space communications. Testing showed the algorithm could accurately detect signals in noise and identify occupied portions of the spectrum between 88-90 MHz and others. Future work could involve networking multiple SDRs to provide real-time spectrum analysis across a wider area.
The document discusses an enhanced multimedia search algorithm called "Time series Active Search Algorithm" that uses feature vectors and histogram pruning to enable faster and more efficient searching of audio and video queries from large stored datasets. The algorithm extracts feature vectors from query and stored signals, classifies the vectors, obtains histograms, compares histograms using a threshold, and notifies of similarities. Experimental results found the algorithm reduced matches to over 1/291 for video and 1/501 for audio, making search very fast and reasonably robust even with noise and compression.
Performance Analysis of Fading Channels on Cooperative Mode Spectrum Sensing ...ijtsrd
Spectrum sensing is the main feature of cognitive radio technology. Spectrum sensing gives an idea of detecting the presence of the primary users in a licensed spectrum. The sensing of radio spectrum is an essential problem in cognitive radio CR networks, where secondary users SUs need to detect the presence of primary users PUs before they use the spectrum allocated to PUs. The detection of primary user status and the spectrum sensing are the major issues in cognitive radio systems. We employ one of the simplest and most efficient Spectrum Sensing technique, the cooperative spectrum sensing with three different digital modulation techniques BPSK, QPSK, 16 QAM. In this paper, we analyze the performance of the cooperative spectrum sensing technique with BPSK, QPSK, 16 QAM modulation techniques over Rayleigh fading Channel. Further, we analyze the performance and BER Bit Error Rate of cooperative spectrum sensing under Rayleigh fading and AWGN channels. The investigation and analysis on cooperative spectrum sensing with above digital modulation techniques can be utilized for future reference of spectrum sensing in the CR networks over AWGN and Rayleigh fading channels. Sangram Singh | Rashmi Raj "Performance Analysis of Fading Channels on Cooperative Mode Spectrum Sensing Technique for Cognitive Radio" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-4 | Issue-3 , April 2020, URL: https://www.ijtsrd.com/papers/ijtsrd30338.pdf Paper Url :https://www.ijtsrd.com/engineering/electronics-and-communication-engineering/30338/performance-analysis-of-fading-channels-on-cooperative-mode-spectrum-sensing-technique-for-cognitive-radio/sangram-singh
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
http://www.logos.ic.i.u-tokyo.ac.jp/~kay/papers/ccgrid2008_stable_broadcast.pdfHiroshi Ono
The document describes a stable broadcast algorithm that improves upon previous algorithms. It proposes constructing both spanning trees and partial trees to broadcast data, ensuring slow nodes never degrade bandwidth for other nodes and maximizing aggregate bandwidth. Simulations and real machine experiments show the algorithm achieves 2.5 times more bandwidth than previous methods and fully utilizes network capacity.
Aggressive Subchannel Allocation Algorithm For Efficient Dynamic Channel Allo...guest3f5c39
The document proposes an Aggressive Sub-channel Allocation (ASA) algorithm for efficient dynamic channel allocation in multi-user OFDMA systems. The ASA algorithm aims to maximize throughput by selecting the user and sub-channel that can achieve the maximum data rate at each allocation interval, without considering fairness among users. Simulation results show that ASA achieves higher throughput than existing algorithms like proportional fairness, but it does not balance throughput across users.
Single Electron Spin Detection Slides For Uno Interviewchenhm
1. The document discusses different algorithms for detecting weak electron spin signals in single electron spin microscopy, including energy detector, matched filter, power-law detector, M-quadratic detector, and generalized likelihood ratio detector.
2. Simulation results show that detection performance improves with more prior knowledge of the signal characteristics, and the M-quadratic detector achieves better performance than the energy detector with lower computation time.
3. Future work involves developing optimal quadratic detection schemes and implementing the algorithms on a computer cluster for real-time signal detection.
This document discusses ultrasound imaging and Doppler ultrasound. It contains questions and answers on topics such as:
- Adjusting gain and transmit power settings and their effects on B-mode images. The operator must optimize settings while avoiding risks.
- How attenuation is compensated for using time gain compensation settings that increase gain over time.
- The importance of a wide dynamic range of echoes to properly display tissues of varying echogenicity. Compression is used to widen this range.
- The Doppler effect used to assess blood velocities, with continuous and pulsed wave Doppler displays. A high-pass filter removes low velocities.
- Examples calculate maximum detectable velocity and check for aliasing based on depth, angle, velocity and
The document summarizes a time and power based positioning scheme for indoor location awareness. It describes a network model with manager, relay, and agent sensor nodes. The scheme uses time difference of arrival and received signal strength from radio and ultrasound signals across three sensor nodes to estimate range and mobile terminal location through trilateration. Performance is evaluated by distributing 12 sensor nodes in a 100m x 100m area and simulating 20 mobile terminals moving randomly between destinations at varying speeds and pause times.
This document proposes and analyzes several algorithms for blind spectrum sensing of OFDM signals in cognitive radio systems. It first shows that the existing cyclic prefix correlation coefficient (CPCC)-based detection algorithm is a special case of the constrained generalized likelihood ratio test (GLRT) in the absence of multipath. It then develops a new multipath-based constrained GLRT (MP-based C-GLRT) algorithm that exploits multipath correlation and outperforms CPCC-based detection in multipath environments. Combining CPCC- and MP-based C-GLRT algorithms provides further performance improvement. The document also develops a GLRT-based detection algorithm for unsynchronized OFDM signals that achieves near-synchron
This paper examines the benefits of applying a priority queueing framework called Priority Queuing with Lower Real Time Utilization Threshold (PQ-LRTU) to Optical Burst Switching (OBS) networks. The researchers use simulation software to show that PQ-LRTU can help overcome the effects of self-similar traffic on OBS networks. Their results show that the burst assembling/disassembling process in OBS introduces additional latency compared to non-OBS networks. However, they also find that there is an optimal real-time utilization threshold between 0.3-0.4 that can minimize delay across different aggregation levels in OBS networks.
Sampling Theorem, Quantization Noise and its types, PCM, Channel Capacity, Ny...Waqas Afzal
Sampling Theorem
Quantization
Noise and its types
Encoding-PCM
Power of Signal
Signal to noise Ratio
Channel Capacity
Nyquist Bandwidth
Shannon Capacity Formula
Multirate Digital Signal Processing-Up/Down Sampling
Applications
This document summarizes the design of a programmable baseband filter for an LTE direct conversion receiver. It discusses LTE specifications and baseband filter requirements, MATLAB simulations to design a 6th order Chebyshev filter, implementing the filter using a leapfrog topology in Cadence software, designing an operational amplifier to meet the filter specifications, and simulating the final filter design to validate it meets LTE bandwidth and blocker requirements. The design is concluded to meet specifications but could be improved by reducing power consumption, using unit resistances, and simulating with an actual OFDMA signal.
A framework for data traffic in cognitive radio net works using trusted token...eSAT Journals
Abstract A cognitive radio network is considered as a key technology for future wireless communications. The motivation behind cognitive ra-dio is the effective usage of limited spectrum. Cognitive radio networks are designed to opportunistically exploit the underutilized or unused spectrum bands. Cognitive radio combines sensing, learning, and optimization algorithms to manage and adapt the radio sys-tem from the physical layer and up the communication stack. Spectrum Sensing, Spectrum Decision, Spectrum Mobility and Spectrum Sharing, are the four functionalities involved in Cognitive Radio Networks. This paper proposes a framework for data traffic man-agement by considering the QoS requirement of the secondary user and also the primary user activity. The Location information of the primary user in cognitive radio networks can be used to assist the communication among secondary users outside the transmission coverage area of primary users and also for tracking the primary user activities. The objective of the paper is to design a framework which will support the secondary user data transmission while considering the primary user activity and QoS requirement. Keywords- Cognitive Radio Networks, Primary User Activity, QoS management, Trusted Token Analyzer
This document summarizes a presentation on tunable dense wavelength division multiplexing passive optical network (DWDM PON) technologies. It discusses the challenges of current passive WDM networks and how tunable DWDM PON can address these by allowing dynamic wavelength tuning. It describes how tunable DWDM PON uses a centralized wavelength control system to tune low-cost tunable transceivers at the optical network units to specific wavelengths allocated by the optical line terminal, enabling high-capacity transparent services over a large number of wavelengths to multiple users.
The document discusses Dense Wavelength Division Multiplexing (DWDM) optical transmission. It provides an introduction to DWDM techniques and components. It discusses how DWDM allows multiple optical carrier signals to be multiplexed on a single optical fiber using different laser light wavelengths. It also discusses the NEMO technology experiment involving DWDM and some of the advances and implementations of DWDM networks and systems.
Multi Channel Protocols In Cognitive Radio NetworksMuhammad Mustafa
Cognitive radio is a paradigm for wireless communication in which either a network or a wireless node changes its transmission or reception parameters to communicate efficiently avoiding interference with licensed or unlicensed users. This alteration of parameters is based on the active monitoring of several factors in the external and internal radio environment, such as radio frequency spectrum, user behaviour and network state. this presentation discusses main approaches and protocols of multichannel cognitive radio networks.
This document discusses dense wavelength division multiplexing (DWDM) technology. It begins with an overview of DWDM, describing how it multiplexes multiple optical carrier signals onto a single optical fiber using different laser light wavelengths. It then provides details on DWDM network architecture, including optical transponders, multiplexers/demultiplexers, optical add-drop multiplexers, optical fiber amplifiers, and the optical supervisory channel. The document also discusses optical frequency bands defined by the ITU and advantages and limitations of DWDM networks.
DWDM is a fiber optic transmission technique that uses different wavelengths of light to transmit multiple data signals simultaneously over the same fiber. This allows network capacity to be dramatically increased to meet rapidly growing bandwidth demands. DWDM provides a flexible solution to fiber exhaust and allows different data formats like IP, ATM, and SONET to be transported over a single optical network. By assigning each signal a unique wavelength, DWDM can multiply the capacity of existing fiber infrastructure.
Optical power debugging in dwdm system having fixed gain amplifierseSAT Journals
Abstract
This article covers optical power measurement of light signal in DWDM network and debugging of optical power as per the specifications of DWDM system with fix gain amplifier. The measurement and calculations of each component of DWDM system is discussed individually. Optical power of individual optical channel, aggregate optical power of multiplexed signals, relation with amplifier gain, insertion loss and attenuation on signal are the key factors involved in design and operation of DWDM system. From transmitter to receiver, the working performance of the DWDM system depends on the optical strength of input light signal should be as per specifications of its components. A description of input and output optical power of light signal of each DWDM component and its relationship is discussed. If there is any deviation as per specifications is observed, process to calculate deviation and debug is given with working example in this article.
Keywords: Dense wavelength division multiplexing (DWDM), Optical MUX/DEMUX, Optical transmitters/receivers, Optical amplifiers, Optical Fiber, Optical power, Attenuation, Optical Power Debugging
Bandwidth is Becoming Commodity :
Price per bit went down by 99% in the last 5 years on the optical side
This is one of the problems of the current telecom market
Optical Metro – cheap high bandwidth access
$1000 a month for 100FX (in major cities)
This is less than the cost of T1 several years ago
Optical Long-Haul and Metro access - change of the price point
Reasonable price drive more users (non residential)
This document discusses cognitive radio in 5G networks. It begins with describing the evolution of mobile standards from 1G to 4G. It then introduces the concepts of 5G and cognitive radio. The key points are:
- 5G will provide very high data rates up to 1 Gbps and connect many more devices.
- Cognitive radio can improve spectrum efficiency by allowing unlicensed users to access licensed spectrum holes.
- The document proposes a cognitive radio based 5G network that can integrate various wireless technologies and help manage network complexity using cognitive radio's abilities.
DWDM is a technology that puts data from different sources together on an optical fiber, with each signal carried at the same time on its own separate light wavelength. It works by combining and transmitting multiple signals simultaneously at different wavelengths on the same fiber. A DWDM system includes optical fibers, multiplexers and demultiplexers to combine and separate the signals, and repeaters to amplify signals over long distances. It provides benefits like increased network capacity, upgradability without new fibers, and transparency to data rates and protocols. DWDM is well-suited for long-distance telecommunications operators and building or expanding fiber optic networks.
CWDM and DWDM are both types of WDM systems that transmit multiple wavelengths of laser light through a single optical fiber. However, they differ in channel spacing, transmission reach, and cost. CWDM has a wider channel spacing of 20nm, a shorter transmission reach of 160km, and a lower cost compared to DWDM. DWDM has a narrower channel spacing of 0.2-0.8nm, can transmit signals over longer distances, and has a higher cost due to its use of temperature-controlled lasers. The key differences are that CWDM is cheaper but has lower performance, while DWDM has a higher performance but also a higher cost.
An overview of cognitive radio, comparison of cognitive radio vs. conventional radio, real-world applications for cognitive radio networks, how cognitive radios improve spectrum efficiency and address the wireless spectrum shortage.
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
http://www.logos.ic.i.u-tokyo.ac.jp/~kay/papers/ccgrid2008_stable_broadcast.pdfHiroshi Ono
The document describes a stable broadcast algorithm that improves upon previous algorithms. It proposes constructing both spanning trees and partial trees to broadcast data, ensuring slow nodes never degrade bandwidth for other nodes and maximizing aggregate bandwidth. Simulations and real machine experiments show the algorithm achieves 2.5 times more bandwidth than previous methods and fully utilizes network capacity.
Aggressive Subchannel Allocation Algorithm For Efficient Dynamic Channel Allo...guest3f5c39
The document proposes an Aggressive Sub-channel Allocation (ASA) algorithm for efficient dynamic channel allocation in multi-user OFDMA systems. The ASA algorithm aims to maximize throughput by selecting the user and sub-channel that can achieve the maximum data rate at each allocation interval, without considering fairness among users. Simulation results show that ASA achieves higher throughput than existing algorithms like proportional fairness, but it does not balance throughput across users.
Single Electron Spin Detection Slides For Uno Interviewchenhm
1. The document discusses different algorithms for detecting weak electron spin signals in single electron spin microscopy, including energy detector, matched filter, power-law detector, M-quadratic detector, and generalized likelihood ratio detector.
2. Simulation results show that detection performance improves with more prior knowledge of the signal characteristics, and the M-quadratic detector achieves better performance than the energy detector with lower computation time.
3. Future work involves developing optimal quadratic detection schemes and implementing the algorithms on a computer cluster for real-time signal detection.
This document discusses ultrasound imaging and Doppler ultrasound. It contains questions and answers on topics such as:
- Adjusting gain and transmit power settings and their effects on B-mode images. The operator must optimize settings while avoiding risks.
- How attenuation is compensated for using time gain compensation settings that increase gain over time.
- The importance of a wide dynamic range of echoes to properly display tissues of varying echogenicity. Compression is used to widen this range.
- The Doppler effect used to assess blood velocities, with continuous and pulsed wave Doppler displays. A high-pass filter removes low velocities.
- Examples calculate maximum detectable velocity and check for aliasing based on depth, angle, velocity and
The document summarizes a time and power based positioning scheme for indoor location awareness. It describes a network model with manager, relay, and agent sensor nodes. The scheme uses time difference of arrival and received signal strength from radio and ultrasound signals across three sensor nodes to estimate range and mobile terminal location through trilateration. Performance is evaluated by distributing 12 sensor nodes in a 100m x 100m area and simulating 20 mobile terminals moving randomly between destinations at varying speeds and pause times.
This document proposes and analyzes several algorithms for blind spectrum sensing of OFDM signals in cognitive radio systems. It first shows that the existing cyclic prefix correlation coefficient (CPCC)-based detection algorithm is a special case of the constrained generalized likelihood ratio test (GLRT) in the absence of multipath. It then develops a new multipath-based constrained GLRT (MP-based C-GLRT) algorithm that exploits multipath correlation and outperforms CPCC-based detection in multipath environments. Combining CPCC- and MP-based C-GLRT algorithms provides further performance improvement. The document also develops a GLRT-based detection algorithm for unsynchronized OFDM signals that achieves near-synchron
This paper examines the benefits of applying a priority queueing framework called Priority Queuing with Lower Real Time Utilization Threshold (PQ-LRTU) to Optical Burst Switching (OBS) networks. The researchers use simulation software to show that PQ-LRTU can help overcome the effects of self-similar traffic on OBS networks. Their results show that the burst assembling/disassembling process in OBS introduces additional latency compared to non-OBS networks. However, they also find that there is an optimal real-time utilization threshold between 0.3-0.4 that can minimize delay across different aggregation levels in OBS networks.
Sampling Theorem, Quantization Noise and its types, PCM, Channel Capacity, Ny...Waqas Afzal
Sampling Theorem
Quantization
Noise and its types
Encoding-PCM
Power of Signal
Signal to noise Ratio
Channel Capacity
Nyquist Bandwidth
Shannon Capacity Formula
Multirate Digital Signal Processing-Up/Down Sampling
Applications
This document summarizes the design of a programmable baseband filter for an LTE direct conversion receiver. It discusses LTE specifications and baseband filter requirements, MATLAB simulations to design a 6th order Chebyshev filter, implementing the filter using a leapfrog topology in Cadence software, designing an operational amplifier to meet the filter specifications, and simulating the final filter design to validate it meets LTE bandwidth and blocker requirements. The design is concluded to meet specifications but could be improved by reducing power consumption, using unit resistances, and simulating with an actual OFDMA signal.
A framework for data traffic in cognitive radio net works using trusted token...eSAT Journals
Abstract A cognitive radio network is considered as a key technology for future wireless communications. The motivation behind cognitive ra-dio is the effective usage of limited spectrum. Cognitive radio networks are designed to opportunistically exploit the underutilized or unused spectrum bands. Cognitive radio combines sensing, learning, and optimization algorithms to manage and adapt the radio sys-tem from the physical layer and up the communication stack. Spectrum Sensing, Spectrum Decision, Spectrum Mobility and Spectrum Sharing, are the four functionalities involved in Cognitive Radio Networks. This paper proposes a framework for data traffic man-agement by considering the QoS requirement of the secondary user and also the primary user activity. The Location information of the primary user in cognitive radio networks can be used to assist the communication among secondary users outside the transmission coverage area of primary users and also for tracking the primary user activities. The objective of the paper is to design a framework which will support the secondary user data transmission while considering the primary user activity and QoS requirement. Keywords- Cognitive Radio Networks, Primary User Activity, QoS management, Trusted Token Analyzer
This document summarizes a presentation on tunable dense wavelength division multiplexing passive optical network (DWDM PON) technologies. It discusses the challenges of current passive WDM networks and how tunable DWDM PON can address these by allowing dynamic wavelength tuning. It describes how tunable DWDM PON uses a centralized wavelength control system to tune low-cost tunable transceivers at the optical network units to specific wavelengths allocated by the optical line terminal, enabling high-capacity transparent services over a large number of wavelengths to multiple users.
The document discusses Dense Wavelength Division Multiplexing (DWDM) optical transmission. It provides an introduction to DWDM techniques and components. It discusses how DWDM allows multiple optical carrier signals to be multiplexed on a single optical fiber using different laser light wavelengths. It also discusses the NEMO technology experiment involving DWDM and some of the advances and implementations of DWDM networks and systems.
Multi Channel Protocols In Cognitive Radio NetworksMuhammad Mustafa
Cognitive radio is a paradigm for wireless communication in which either a network or a wireless node changes its transmission or reception parameters to communicate efficiently avoiding interference with licensed or unlicensed users. This alteration of parameters is based on the active monitoring of several factors in the external and internal radio environment, such as radio frequency spectrum, user behaviour and network state. this presentation discusses main approaches and protocols of multichannel cognitive radio networks.
This document discusses dense wavelength division multiplexing (DWDM) technology. It begins with an overview of DWDM, describing how it multiplexes multiple optical carrier signals onto a single optical fiber using different laser light wavelengths. It then provides details on DWDM network architecture, including optical transponders, multiplexers/demultiplexers, optical add-drop multiplexers, optical fiber amplifiers, and the optical supervisory channel. The document also discusses optical frequency bands defined by the ITU and advantages and limitations of DWDM networks.
DWDM is a fiber optic transmission technique that uses different wavelengths of light to transmit multiple data signals simultaneously over the same fiber. This allows network capacity to be dramatically increased to meet rapidly growing bandwidth demands. DWDM provides a flexible solution to fiber exhaust and allows different data formats like IP, ATM, and SONET to be transported over a single optical network. By assigning each signal a unique wavelength, DWDM can multiply the capacity of existing fiber infrastructure.
Optical power debugging in dwdm system having fixed gain amplifierseSAT Journals
Abstract
This article covers optical power measurement of light signal in DWDM network and debugging of optical power as per the specifications of DWDM system with fix gain amplifier. The measurement and calculations of each component of DWDM system is discussed individually. Optical power of individual optical channel, aggregate optical power of multiplexed signals, relation with amplifier gain, insertion loss and attenuation on signal are the key factors involved in design and operation of DWDM system. From transmitter to receiver, the working performance of the DWDM system depends on the optical strength of input light signal should be as per specifications of its components. A description of input and output optical power of light signal of each DWDM component and its relationship is discussed. If there is any deviation as per specifications is observed, process to calculate deviation and debug is given with working example in this article.
Keywords: Dense wavelength division multiplexing (DWDM), Optical MUX/DEMUX, Optical transmitters/receivers, Optical amplifiers, Optical Fiber, Optical power, Attenuation, Optical Power Debugging
Bandwidth is Becoming Commodity :
Price per bit went down by 99% in the last 5 years on the optical side
This is one of the problems of the current telecom market
Optical Metro – cheap high bandwidth access
$1000 a month for 100FX (in major cities)
This is less than the cost of T1 several years ago
Optical Long-Haul and Metro access - change of the price point
Reasonable price drive more users (non residential)
This document discusses cognitive radio in 5G networks. It begins with describing the evolution of mobile standards from 1G to 4G. It then introduces the concepts of 5G and cognitive radio. The key points are:
- 5G will provide very high data rates up to 1 Gbps and connect many more devices.
- Cognitive radio can improve spectrum efficiency by allowing unlicensed users to access licensed spectrum holes.
- The document proposes a cognitive radio based 5G network that can integrate various wireless technologies and help manage network complexity using cognitive radio's abilities.
DWDM is a technology that puts data from different sources together on an optical fiber, with each signal carried at the same time on its own separate light wavelength. It works by combining and transmitting multiple signals simultaneously at different wavelengths on the same fiber. A DWDM system includes optical fibers, multiplexers and demultiplexers to combine and separate the signals, and repeaters to amplify signals over long distances. It provides benefits like increased network capacity, upgradability without new fibers, and transparency to data rates and protocols. DWDM is well-suited for long-distance telecommunications operators and building or expanding fiber optic networks.
CWDM and DWDM are both types of WDM systems that transmit multiple wavelengths of laser light through a single optical fiber. However, they differ in channel spacing, transmission reach, and cost. CWDM has a wider channel spacing of 20nm, a shorter transmission reach of 160km, and a lower cost compared to DWDM. DWDM has a narrower channel spacing of 0.2-0.8nm, can transmit signals over longer distances, and has a higher cost due to its use of temperature-controlled lasers. The key differences are that CWDM is cheaper but has lower performance, while DWDM has a higher performance but also a higher cost.
An overview of cognitive radio, comparison of cognitive radio vs. conventional radio, real-world applications for cognitive radio networks, how cognitive radios improve spectrum efficiency and address the wireless spectrum shortage.
The document discusses cognitive radio and its benefits. It defines cognitive radio as a radio that is aware of its surroundings and adapts intelligently. Cognitive radio provides a framework for devices to dynamically create links by sensing the environment, evaluating options, and implementing the best waveform. This allows for improved spectrum utilization and quality of service. Some applications of cognitive radio include extending mobile networks, emergency radio systems, and multi-technology phones.
Three techniques for generating millimeter-wave signals for high-capacity wireless links are discussed:
1) Direct intensity modulation with direct detection, which is difficult to scale to high frequencies.
2) Photonic generation and RF heterodyning, which requires stringent laser linewidth requirements but is scalable to high frequencies.
3) Experimental generation of a 100Gbps wireless signal using optical baseband 16-QAM generation, photonic upconversion with a free-running laser, and double-stage downconversion.
1) Cognitive radio is a smart radio that can identify idle spectrum to transmit its own signals. It is based on software-defined radio and allows for opportunistic usage of available frequencies not being used by primary users.
2) Spectrum sensing techniques like cyclostationary feature detection can be used to detect primary user transmissions by analyzing the cyclic spectral correlation function. This method is more reliable and provides noise immunity.
3) Cooperative spectrum sensing allows multiple cognitive radios to cooperate and share sensing results to overcome issues like shadowing and multipath fading. This improves detection accuracy and agility.
DWDM & Packet Optical Fundamentals by Dion Leung [APRICOT 2015]APNIC
This document provides an overview of optical networking fundamentals and components for designing DWDM networks. It discusses:
- Key components used to build optical networks including fiber, transceivers, muxponders, amplifiers, and dispersion compensation modules.
- Design considerations for point-to-point and multi-node linear DWDM networks such as length, number of fiber strands, fiber type and condition, transmission capacity needs, and calculating power budgets.
- The roles of optical amplifiers and dispersion compensation in extending transmission reach over long distances and high bitrates.
- A quick summary of the essential "lego blocks" used to construct metro and regional optical networks.
The autonomic nervous system (ANS) controls involuntary functions like heartbeat, breathing, and digestion. It has two divisions - the sympathetic and parasympathetic systems.
The sympathetic system prepares the body for "fight or flight" through actions like increasing heart rate. It uses norepinephrine as a neurotransmitter. The parasympathetic system allows the body to "rest and digest" through actions like slowing the heart rate. It uses acetylcholine as a neurotransmitter.
Both systems involve two neurons - a preganglionic neuron from the CNS and a postganglionic neuron. They differ in the lengths of their neurons and the locations of their cell bodies. Together they work to maintain homeostasis through complementary
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Optimizing the Number of Samples for Multi-Channel Spectrum Sensing
1. IEEE ICC, 8-12 June 2015
Saud Althunibat, Yung Manh Vuong & Fabrizio Granelli
University of Trento
Trento, Italy.
“Optimizing the Number of Samples for
Multi-Channel Spectrum Sensing “
2. 2
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Outline
Conclusions
Throughput maximization setup
Problem Statement
Introduction : Cognitive Radio
Interference minimization setup
State of the art
Simulation Results
Energy minimization setup
3. 3
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8-12 June 2015
Cognitive Radio
• Cognitive Radio targets the problem of spectrum
scarcity by dynamically exploiting the underutilisation of
the spectrum among the operators.
• Operation: Access the spectrum of another system,
called “primary system”, with minimum interference
and without impact on the QoS of the primary system.
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Spectrum Sensing
Aims at identifying the instantaneous
spectrum status to use the unoccupied
portions.
High sensing requirements should be
satisfied to avoid interference.
Usually performed in a collaborative
approach, called collaborative spectrum
sensing (CSS).
6. 6
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The problem
• Our main problem is the high resource
consumption (including time and energy)
during spectrum sensing stage.
• Why ?
Continuous process.
Large number of users.
Large number of channels.
Large amount of information.
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State of the art
• Several approaches:
• Reducing the number of sensing users.
• Reducing the number of reporting users
(confidence voting).
• Reducing the number of sensed channels.
• Clustering.
• Optimizing the fusion rule.
• Gamy theory.
8. 8
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Contributions
• In this work we optimize the number of
samples to be collected from each channel
in a multi-channel spectrum sensing.
• Different setups have been considered:
oThroughput Maximization
oInterference Minimization
oEnergy Minimization
9. 9
IEEE ICC
8-12 June 2015
Throughput Maximization Setup
… (1)
• For L channels, the average achievable throughput can
be expressed as follows:
Where
P0 : the probability that the channel is idle.
R: the data rate.
Tt : the transmission time.
Pfi : the false-alarm probability of the ith channel.
10. 10
IEEE ICC
8-12 June 2015
Throughput Maximization Setup
…(2)
• The throughput maximization problem with a constraint
on the total number of samples (ST) can be expressed
as follows:
• Notice that Pfi is a function of Si (the no. of samples)
as follows:
11. 11
IEEE ICC
8-12 June 2015
Throughput Maximization Setup
…(3)
• The problem can be solved using Lagrange method as
follows:
• Which can be approximated as follows:
12. 12
IEEE ICC
8-12 June 2015
Interference Minimization Setup
…(1)
• As the interference occurs in the missed-detection case,
it can be modeled for L channels as follows:
Where
P1 : the probability that the channel is busy.
Pt : the transmit power.
Tt : the transmission time.
Pdi : the detection probability of the ith channel.
13. 13
IEEE ICC
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Interference Minimization Setup
…(2)
• The Interference minimization problem with a
constraint on the total number of samples (ST) can be
expressed as follows:
• Notice that Pdi is a function of Si (the no. of samples)
as follows:
14. 14
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8-12 June 2015
Interference Minimization Setup
…(3)
• The solution is also can be approximated using the
same procedure:
15. 15
IEEE ICC
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Energy Minimization Setup …(1)
• The energy consumed in sensing L channels can be
expressed as follows:
Where
Ps : the sensing power.
fs : the transmission time.
16. 16
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Energy Minimization Setup …(2)
• The energy minimization problem with a constraint on
the achievable throughput can be formulated as follows
:
where DT is the lowest acceptable throughput
17. 17
IEEE ICC
8-12 June 2015
Energy Minimization Setup …(3)
• Similarly, the optimal no. of samples collected form the
ith channel can be approximated as follows
18. 18
IEEE ICC
8-12 June 2015
• Once two channels have
equal noise variance (σ ),
the same no. of samples
should be collected from
both.
• If the noise variance is
larger than detection
threshold (λ) , the number
of samples is zero.
• For a maximum throughput,
if the channel has a noise
variance more than the
detection threshold, it
should not be sensed.
Simulation Results …(1)
Optimal no. of samples versus the noise variance
of the 3rd channel (σ2
1 =0.45, σ2
2 =0.65)
19. 19
IEEE ICC
8-12 June 2015
• If the sum of the noise and
signal variances of two
different channels is equal,
the same no. of samples
should be collected from
both.
• For a minimum interference,
if the channel has a sum of
noise and signal variances
less than the detection
threshold, it should not be
sensed.
Simulation Results …(2)
Optimal no. of samples versus the sum of the
noise and signal variances of the 3rd channel .
20. 20
IEEE ICC
8-12 June 2015
• If the noise variance of
two different channels is
equal, the same no. of
samples should be
collected from both.
• For a minimum energy
consumption, if the
channel has a noise
variance more than the
detection threshold, it
should not be sensed.
Simulation Results …(3)
Optimal no. of samples versus the noise variance
of the 3rd channel .
21. 21
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Conclusions
• Optimization of the number of samples from each channel in multi
channel spectrum sensing is addressed.
• Three different setups have been considered:
• Throughput maximization with a constraint on the total number of
samples.
• Interference minimization with a constraint on the total number of
samples.
• Energy minimization with a constraint on the achievable throughput.
• Approximated solutions have been proposed for the optimal number
samples to be collected from each channel for each setup.
22. 22
IEEE ICC
8-12 June 2015
Conclusions
• Mathematical and simulation results allow to conclude that:
• For maximum throughput, if the channel has a noise variance
higher than the detection threshold, it should not be sensed.
• For minimum interference, if the channel has a sum of noise
and signal variances lower than the detection threshold, it
should not be sensed.
• For minimum energy consumption, if the channel has a noise
variance higher than the detection threshold, it should not be
sensed.
23. 23
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8-12 June 2015
Thanks for your kind attention!
Fabrizio Granelli
granelli@disi.unitn.it
Editor's Notes
A general figure to show the spectrum hole concept.
Lambda is the detection threshold, and \Sigma^2 is the noise variance.
The first equation is NOT a closed form since “S” appears in both sides. Hence, we approximate it using an approximation of the exponential function. (n : is a very large number used in the approximation)
\delta^2 is the variance of the transmitted signal over the ith channel
. (n : is a very large number used in the approximation)
(n : is a very large number used in the approximation)
The detection threshold λ=1, σ21 (=0.45): is the noise variance of the 1st channel, σ22 (=0.65): the noise variance of the 2nd channel
The detection threshold λ=1, δ21 : is the licensed signal variance over the 1st channel, δ22 :is the licensed signal variance over the 2nd channel,