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Hf Communications Systems And Technology
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Book Synopsis HF Communications Systems and Technology by : John M. Goodman
Download or read book HF Communications Systems and Technology written by John M. Goodman and published by Springer. This book was released on 1992-05-28 with total page 664 pages. Available in PDF, EPUB and Kindle. Book excerpt: Communications engineers, ionospheric scientists, engineers and scientists in DoD HF projects, and DoD managers will use this source to gain a working understanding of the basic theory involved in HF radiowave propagation and uses of HF technology today.
Book Synopsis HF Communications by : Nicholas M Maslin
Download or read book HF Communications written by Nicholas M Maslin and published by CRC Press. This book was released on 2017-06-30 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt: Communications using the high frequency spectrum (2-30 MHz) have experienced a considerable resurgence. In recent years, powerful microcomputers and VLSI technology have greatly enhanced the prospects of overcoming many of the unique problems that formerly afflicted the HF systems More...designer. The aim of this book, therefore, is to provide a fi
Book Synopsis HF Radio Communications System Design Assessment Study. Task 3.2C. Technology Approaches for the Real-Life HF Environment by : R. E. Duff
Download or read book HF Radio Communications System Design Assessment Study. Task 3.2C. Technology Approaches for the Real-Life HF Environment written by R. E. Duff and published by . This book was released on 1980 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt: High frequency equipment and system design have been largely ignored by the U.S. Army during the past ten years. This was in anticipation of achieving sufficient and effective communication via use of other frequencies and media. It is now apparent that hf is a more viable and useful tool than previously thought and deserves a role in the U.S. Army's communications system. The problem of now reinstituting hf as an integral part of U.S. Army communications is approached in this CORADCOM study. To better understand the real life hf environment the study team set out to make assessments from several different viewpoints: the communications system, physical, propagation media, noise, EMI/EMC, ECM and the U.S. Army fielded units in Germany. From these assessments the team was able to characterize the hf system in terms of required features and capabilities: ECCM, Nuclear Survivability (for equipment and communications link), Automated and Adaptive, Multi-Type Traffic, Multi-Range, Deployable, Securable, Compatible and Automated Frequency Management.
Book Synopsis Third-generation and Wideband HF Radio Communications by : Eric E. Johnson
Download or read book Third-generation and Wideband HF Radio Communications written by Eric E. Johnson and published by Artech House. This book was released on 2013 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wideband HF. Book jacket.
Book Synopsis Cooperative Techniques for Next Generation HF Communication Systems by : Mohammad Reza Heidarpour
Download or read book Cooperative Techniques for Next Generation HF Communication Systems written by Mohammad Reza Heidarpour and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The high frequency (HF) band lies within 2-30 MHz of the electromagnetic spectrum. For decades, the HF band has been recognized as the primary means of long-range wireless communications. When satellite communication first emerged in 1960s, HF technology was considered to be obsolete. However, with its enduring qualities, HF communication survived through this competition and positioned itself as a powerful complementary and/or alternative technology to satellite communications. HF systems have been traditionally associated with low-rate data transmission. With the shift from analog to digital in voice communication, and increasing demands for high-rate data transmission (e.g., e-mail, Internet, FTP), HF communication has been going through a renaissance. Innovative techniques are required to push the capacity limits of the HF band. In this dissertation, we consider cooperative communication as an enabling technology to meet the challenging expectations of future generation HF communication systems. Cooperative communication exploits the broadcast nature of wireless transmission and relies on the cooperation of users relaying the information to one another. We address the design, analysis, and optimization of cooperative HF communication systems considering both multi-carrier and single-carrier architectures. As the multi-carrier HF system, we consider the combination of the orthogonal frequency division multiplexing (OFDM) with the bit interleaved coded modulation (BICM) as the underlying physical layer platform. It is assumed that cooperating nodes may use different HF propagation mechanisms, such as near-vertical-incidence sky wave (NVIS) and surface wave, to relay their received signals to the destination in different environmental scenarios. Diversity gain analysis, optimum relay selection strategy and power allocation between the source and relays are investigated for the proposed cooperative HF system. For single-carrier HF systems, we first derive a matched-filer-bound (MFB) on the error rate performance of the non-regenerative cooperative systems. The results from the MFB analysis are also used for relay selection and power allocation in the multi-relay cooperative systems. To overcome the intersymbol interference impairment induced by frequency-selectivity of the HF channel, equalization is inevitable at the destination in a single-carrier system. In this work, we investigate the minimum-mean-square-error (MMSE) based linear/decision-feedback frequency domain equalizers (FDEs). Both symbol-spaced and fractionally-spaced implementations of the proposed FDEs are considered and their performance is compared under different channel conditions and sampling phase errors at the relay and destination nodes.
Book Synopsis Coding for Adaptive Frequency Hopping System in HF-communications by : Göran Malmgren
Download or read book Coding for Adaptive Frequency Hopping System in HF-communications written by Göran Malmgren and published by . This book was released on 1993 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Advanced High-frequency Radio Communications by : Eric E. Johnson
Download or read book Advanced High-frequency Radio Communications written by Eric E. Johnson and published by Artech House Publishers. This book was released on 1997 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt: This up-to-date, comprehensive reference and planner's guide presents an in-depth description of automated HF communications.
Book Synopsis Adaptive Frequency Hopping in HF-communications by : Jens Zander
Download or read book Adaptive Frequency Hopping in HF-communications written by Jens Zander and published by . This book was released on 1993 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis HF Radio Communication Systems Design Assessment. Task 3.3f. Real-Time Adaptive Control and Processing by : D. W. Graham
Download or read book HF Radio Communication Systems Design Assessment. Task 3.3f. Real-Time Adaptive Control and Processing written by D. W. Graham and published by . This book was released on 1980 with total page 61 pages. Available in PDF, EPUB and Kindle. Book excerpt: The emphasis in this Real-Time Adaptive Control and Processing task has been on automated frequency management, link connectivity control, channel evaluation, and data transmission adaptation for maximum throughput. The possibilities for a federated processing system were considered as adjunct to maximizing information throughput via the HF communications system. Control aspects for digitally interfaced transmission systems which might connect to the HF channel for further data transmission were not analyzed. The processing and control requirements for automated frequency management have been incorporated in the real-time adaptive control and processing technology analysis. The frequency management capabilities hypothesized have been modeled after the Army's evolving management concepts. A closed-loop concept of frequency management was assumed to be implemented by collecting data at the net station level and transmitting this information, when polled, to the NCS. The NCS would process this information and transmit statistical parameters to the Corps level. This data could be processed further and passed to the Theater Frequency Manager to substantiate Corps requests for different or additional frequencies. Meaningful numbers in terms of measured bit error rates, noise levels, multipath delay spread, and Doppler frequency spread can be used to improve subsequent predictions and frequency assignments.
Book Synopsis Satellite Communications Systems and Technology by : Burton I. Edelson
Download or read book Satellite Communications Systems and Technology written by Burton I. Edelson and published by William Andrew. This book was released on 1995-01-15 with total page 542 pages. Available in PDF, EPUB and Kindle. Book excerpt: Satellite Communications Systems and Technology
Book Synopsis Modern Communications Receiver Design and Technology by : Cornell Drentea
Download or read book Modern Communications Receiver Design and Technology written by Cornell Drentea and published by Artech House. This book was released on 2010 with total page 487 pages. Available in PDF, EPUB and Kindle. Book excerpt: This comprehensive sourcebook thoroughly explores the state-of-the-art in communications receivers, providing detailed practical guidance for constructing an actual high dynamic range receiver from system design to packaging. You also find clear explanations of the technical underpinnings that you need to understand for your work in the field . This cutting-edge reference presents the latest information on modern superheterodyne receivers, dynamic range, mixers, oscillators, complex coherent synthesizers, automatic gain control, DSP and software radios.You find in-depth discussions on system design, including coverage of all pertinent data and tools. Moreover, the book offers you a solid understanding of packaging and mechanical considerations, as well as a look at tomorrowOCOs receiver technology, including new Bragg-cell applications for ultra-wideband electronic warfare receivers. This one-stop resource is packed with over 300 illustrations that support critical topics throughout."
Book Synopsis Space Physics and Aeronomy, Ionosphere Dynamics and Applications by : Chao Huang
Download or read book Space Physics and Aeronomy, Ionosphere Dynamics and Applications written by Chao Huang and published by John Wiley & Sons. This book was released on 2021-05-11 with total page 47 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive review of global ionospheric research from the polar caps to equatorial regions It's more than a century since scientists first identified the ionosphere, the layer of the Earth’s upper atmosphere that is ionized by solar and cosmic radiation. Our understanding of this dynamic part of the near-Earth space environment has greatly advanced in recent years thanks to new observational technologies, improved numerical models, and powerful computing capabilities. Ionosphere Dynamics and Applications provides a comprehensive overview of historic developments, recent advances, and future directions in ionospheric research. Volume highlights include: Behavior of the ionosphere in different regions from the poles to the equator Distinct characteristics of the high-, mid-, and low-latitude ionosphere Observational results from ground- and space-based instruments Ionospheric impacts on radio signals and satellite operations How earthquakes and tsunamis on Earth cause disturbances in the ionosphere The American Geophysical Union promotes discovery in Earth and space science for the benefit of humanity. Its publications disseminate scientific knowledge and provide resources for researchers, students, and professionals. Find out more about the Space Physics and Aeronomy collection in this Q&A with the Editors in Chief
Book Synopsis HF Radio Communication System Design Assessment. Technical Task Report 3.2b. Available and Applicable Existing and Developing Equipments for Interim Use by : John E. Ambrose
Download or read book HF Radio Communication System Design Assessment. Technical Task Report 3.2b. Available and Applicable Existing and Developing Equipments for Interim Use written by John E. Ambrose and published by . This book was released on 1980 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: HF equipment and system design have been largely ignored by the US Army during the past ten years. This was in anticipation of achieving sufficient and effective communication via use of other frequencies and media. It is now apparent that hf is a more viable and useful tool than previously thought and deserves a role in the US Army's communications system. The problem of now reinstituting hf an in integral part of US Army communications is approach in this CORADCOM study as follows: (1) Determine the usefulness of present assets. (2) Determine what are the available and applicable existing equipments that may be used to augment or replace existing assets in the near term (1980 - 1985). These equipments having been largely developed by industry for other military and commercial users. (3) Define technologies and developing equipments that meet US Army post 1985 requirements in coping with 'real life' environment. (4) Investigate specific areas for exploratory research and development for future application. Efforts under this task are directed toward (2) above in which the final result is to identify equipments/systems for interim use (1980 - 1985).
Book Synopsis Modern HF Signal Detection and Direction Finding by : Jay R. Sklar
Download or read book Modern HF Signal Detection and Direction Finding written by Jay R. Sklar and published by MIT Press. This book was released on 2018-09-25 with total page 369 pages. Available in PDF, EPUB and Kindle. Book excerpt: Detailed descriptions of detection, direction-finding, and signal-estimation methods, using consistent formalisms and notation, emphasizing HF antenna array sensing applications. Adaptive antenna array technology encompasses many powerful interference suppression approaches that exploit spatial differences among signals reaching a radio receiver system. Today, worldwide propagation phenomenology occurring in the High Frequency (HF) radio regime has made such interference common. In this book, Jay Sklar, a longtime researcher at MIT Lincoln Laboratory, presents detailed descriptions of detection, direction-finding, and signal-estimation methods applicable at HF, using consistent formalisms and notation. Modern electronic system technology has made many of these techniques affordable and practical; the goal of the book is to offer practicing engineers a comprehensive and self-contained reference that will encourage more widespread application of these approaches. The book is based on the author's thirty years of managing MIT Lincoln Laboratory work on the application of adaptive antenna array technologies to the sensing of HF communication signals. After an overview of HF propagation phenomenology, communication signal formats, and HF receiver architectural approaches, Sklar describes the HF propagation environment in more detail; introduces important modulation approaches and signaling protocols used at HF; discusses HF receiver system architectural features; and addresses signal processor architecture and its implementation. He then presents the technical foundation for the book: the vector model for a signal received at an adaptive array antenna. He follows this with discussions of actual signal processing techniques for detection and direction finding, including specific direction-finding algorithms; geolocation techniques; and signal estimation.
Book Synopsis HF Radio Communications System Design Assessment. Technical Task Report 3.2a. Evaluation of Present HF Equipment by : Calvin H. Cerva
Download or read book HF Radio Communications System Design Assessment. Technical Task Report 3.2a. Evaluation of Present HF Equipment written by Calvin H. Cerva and published by . This book was released on 1980 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: HF equipment and system design have been largely ignored by the U.S. Army during the past ten years. This was in anticipation of achieving sufficient and effective communication via use of other frequencies and media. It is now apparent that HF is a more viable and useful tool than previously thought and deserves a role in the U.S. Army's communications system. The problem of now re-instituting HF as an integral part of U.S. Army communications is approached in this CORADCOM study as follows: a. Determine the usefulness of present assets. b. Determine what are the available and applicable existing equipments that may be used to augment or replace existing assets in the near-term (1980 - 1985). These equipments having been largely developed by industry for other military and commercial users. c. Define technologies and developing equipments that meet U.S. Army post 1985 requirements in coping with 'real life' environment. d. Investigate specific areas for exploratory research and development for future application. Efforts under this task are directed toward (a) above in which the final results determine the usefulness of present operational HF equipments.
Book Synopsis A Low Power HF Communication System by : John Martin Wilson
Download or read book A Low Power HF Communication System written by John Martin Wilson and published by . This book was released on 2012 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: The HF band of radio frequencies, from 3-30 MHz, is unique in its property that it is refracted by the ionosphere. This property allows long distance radio telecommunications around the world without requiring infrastructure. High frequency (HF) communication has been largely superseded by satellite and cellular technologies for day-to-day communications, due to the tight bandwidth constraints and technical difficulties inherent in using it. However there is still a need for HF communications devices where existing infrastructure is not available, such as in remote or polar locations, or in emergency situations due to natural disasters. This research is aimed at the development of an asymmetric HF communications link, with a battery-powered remote unit that transmits a small amount of data to a mains-powered base station. New technologies are identified and evaluated for use in the link, with the aim of reducing the power requirements of the remote unit. Error correction techniques are investigated. Low-density parity check (LDPC) codes, which are powerful codes used for forward error correction, are suggested for use in the link. Quasi-cyclic LDPC codes allow the low-power transmitter unit to use a computationally simple encoder based on feedback shift registers for generating the LDPC block codes cheaply. Semi-blind LDPC turbo equalisation is a powerful technique that can be used at the base station which utilises the structure of the LDPC code to encode the data stream. This equalises a received signal with a minimal amount of training data required, reducing the duty cycle of the remote unit. Hybrid automatic repeat request (HARQ) techniques are also investigated, which increase the throughput of a link when data repeats are required. A novel HARQ techniquewas created and proven to increase throughput in links with noise. As the proposed system may be deployed in remote locations, or locations where it might be difficult or undesirable to erect a proper HF antenna, a selection of buried antennas are characterised. A design for a remote unit is suggested. This unit was manufactured and used to test the capability of inexpensive, low power hardware to implement the proposed remote unit algorithms.
Book Synopsis HF Silicon ICs for Wide-band Communication Systems by : Leo C. N. de Vreede
Download or read book HF Silicon ICs for Wide-band Communication Systems written by Leo C. N. de Vreede and published by . This book was released on 1996 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt:
