Download or read book Multiple Access Performance of Frequency hopped MFSK with List Metric Detection Over Additive Power Channels written by Mark Alan Creighton and published by . This book was released on 1984 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Frequency Hopped M arcy Frequency Shift Keyed Communications Using List Metric Decoding Over Jamming and Multiple Access Channels written by Mark A. Creighton and published by . This book was released on 1986 with total page 387 pages. Available in PDF, EPUB and Kindle. Book excerpt: List metric decoding is applied to anti-jam and multiple access communication systems that employ frequency-hopped, M-ary Frequency Shift Keyed (MFSK) modulation. The performance of these systems over Guassian noise and Rayleigh fading channels is analyzed by deriving expressions for the cutoff rate parameter RO, and evaluating numerical examples. RO represents the largest reliable data rate per coded symbol that could be achieved, with a particular system and channel, by using practical coding methods. Because it is code-independent, RO is used as the basis for comparing list decoding against hard and soft decisions, without the encumbrance of analyzing specific error correcting codes. RO is then used later, along with a code-dependent function, to upper bound the bit error probability provided by a particular code. In a list decoding receiver, decisions are based on the relative magnitudes of the demodulator's energy detector outputs.

Download or read book Frequency Hopped M ary Frequency Shift Keyed Communications Using List Metric Decoding Over Jamming and Multiple Access Channels written by Mark Alan Creighton and published by . This book was released on 1986 with total page 718 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1987 with total page 1126 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.

Download or read book Anti jam Analysis of Frequency Hopping M ary Frequency Shift Keying Communication Systems in High Frequency Rayleigh Fading Channels written by Dan Avidor and published by . This book was released on 1981 with total page 157 pages. Available in PDF, EPUB and Kindle. Book excerpt: A certain type of M-ary Frequency Shift Keying (MFSK) communication systems, which use Frequency Hopping (FH) to combat jamming is studied in this work. In particular, the performance of such systems over High Frequency (HF) sky-wave channels, when subjected to intentional jamming, is the main topic of this study. The channels considered are characterized by Rayleigh fading and additive Gaussian noise. To combat jamming the communication system hops over the total spread spectrum bandwidth, which is many times larger than the 'instantaneous' bandwidth occupied by the MFSK signal. Located within the HF band and using sky-wave as the dominant propagation mode, the spread spectrum bandwidth is typically nonuniform, time dependent, and congested by many other users of the electromagnetic spectrum. In such an environment, Frequency Hopping FH mfsk systems seem to be more practical than 'Direct Sequence' spectrum spreading techniques. A FH/MFSK system can be easily programmed to use a noncontiguous band, thereby avoiding strong interfering signals that should not be interfered with.

Download or read book Performance Analysis for Fast Frequency Hopped Spread Spectrum Multiple Access Communications written by E. A. Geraniotis and published by . This book was released on 1981 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Time Domain Simulation of MFSK Communications System Performance in the Presence of Wideband Noise and Co Channel Interference written by Tsiridia Konstantinos and published by . This book was released on 1998-12-01 with total page 139 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis models of MFSK digital communications systems were developed using Matlab Simulink and Communications Toolbox. The models were employed to verify MFSK performance in the presence of additive noise and predict MFSK performance for additive noise and co-channel interference. Results are presented for bit-error rate as functions of the signal-to-noise and signal- to-interference power ratios. The results for coherent detection of MFSK (M=2,4, 8) in the presence of additive white Gaussian noise show excellent agreement with the theory. On the other hand, simulation results for the probability of bit error for non- coherent detection of MFSK differ (-21% average) from the theory suggesting a possible systematic' error in the Communications Toolbox implementation of the non-coherent MFSK detection.

Download or read book Performance Analysis of Frequency Hopping MFSK M ary Frequency Shift Keying Systems Employing Forward Error Control Coding in the Presence of Hostile Interference written by Jhong S. Lee and published by . This book was released on 1987 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt: Error probability analyses are performed for a coded M-ary frequency-shift-keying (MFSK) system employing L hops per M-ary word frequency-hopping (FH) spread spectrum waveforms transmitted over a partial-band Gaussian noise jamming channel. The information bit error probabilities are obtained for a square-law linear combining demodulator and for a square-law adaptive gain control (AGC) demodulator, both with forward error control (FEC) coding under conditions of worst-case partial-band noise jamming, using exact analyses of the demodulator performance which include both thermal noise and jamming noise. Parametric performance curves are obtained for both block codes and convolutional codes with both binary and M-ary channel modulations. The results show that thermal noise can not be neglected in the analyses if correct determinations of the optimum order of diversity and the worst-case jamming fraction are to be obtained over the whole range of signal-to-thermal noise and signal-to-jamming ratios. It is shown that the combination of non-linear combining, M-ary modulation, and forward error control coding is an effective strategy against worst-case partial-band noise jamming. However, just as was found to be the case for uncoded systems, the linear combiner is ineffective in worst-case partial-band noise jamming. (Author).

Download or read book Performance of Fast Frequency Hopped MFSK Spread Spectrum Communication in the Presence of AWGN and Tone Jamming written by Robert Ward White and published by . This book was released on 1989 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Performance Analysis of an Ultra Low Power MFSK System written by Yi Xiang and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this dissertation, we investigate the problem of designing an ultra-low power M-ary frequency shift keying (MFSK) system. In Chapter 2, We design a communication system that operates under stringent power constraints, but is flexible with bandwidth constraints. Our approach is to consider some of the key elements in a transceiver and optimize them for low power consumption, as opposed to optimizing them to minimize, say, average probability of error. An obvious consequence of this is that high complexity components of the system, such as matched filters, forward error correction that employs iterative decoders, coherent demodulators, and bandwidth-efficient modulation formats, are not feasible for this research. Rather, our system is designed using MFSK with non-coherent detection, optimized two-pole bandpass filters (BPF), and Reed-Solomon (RS) codes with hard-decision decoding. Among other things, we show that by properly optimizing the key parameters of the BPFs and RS codes, we can design the system to be significantly less complex than an optimal one, and only lose about 1.2 dB in terms of performance. In Chapter 3, We extend the results from Chapter 2 to incorporate fast frequency hopping (FFH) and intelligent jamming. The system still operates under stringent power constraints, but is flexible with bandwidth constraints. Our system is designed using MFSK with non-coherent detection and fast frequency hopping (FFH), optimized two-pole BPF, and RS codes with hard-decision decoding. Among other things, we show that by properly optimizing the key parameters of the BPFs and RS codes, we can design the system to be significantly less complex than the MF system with a performance loss of less than 1.4 dB in terms of performance in most scenarios that we considered. Further, the 2-pole BPF system can actually outperform the corresponding MF system by up to 2.4 dB with multi-tone jamming. In Chapter 4, we extend the results from Chapter 2 to incorporate Gaussian filtering. We improve our previous design by considering the power-bandwidth tradeoff, and we show that we can save a large percentage of system bandwidth by sacrificing a small amount of power, when the demodulator and coding parameters are optimized. For example, we can save 50% of system bandwidth at the cost of 1 dB loss in performance compared to our previous system design. We quantify the performance loss as a function of both the system bandwidth saved and the time-bandwidth product of the Gaussian filter. We keep M = 16 as our baseline design, and compare the performance of the M-ary GFSK system with the corresponding MFSK system.

Download or read book Performance Analyses of Frequency hopped Spread spectrum Multiple Access Systems in Fading Environments written by Usa Svasti-Xuto and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The focus of this dissertation is the performance analyses of two classes of frequency-hopped spread-spectrum multiple access (FH-SSMA) systems in various fading environments. The capacity of Viterbi's FH-SSMA system is evaluated under three types of fading, namely Rician, shadowed Rician, and Nakagami fading. The results of recent experiments have indicated that these fading phenomena occur in various environments where the FH-SSMA system may be implemented. In this dissertation, the deletion probability for each fading scenario is derived. Subsequently, the system capacity is analyzed in terms of maximum number of users versus average bit error rate. The effect of a change in the signal-to-noise ratio level on the system capacity is also demonstrated. For Rician fading, it is found that the capacity of the system with a Rician factor of 2 dBis reduced by 13 percent as compared to the capacity of the non-fading case. For shadowed Rician fading, three shadowing scenarios are considered: light, average, and heavy. It is shown that the light and the average shadowing scenarios provide only a slight decrease in the capacity, while the heavy shadowing scenario renders a capacity identical to that for the Rayleigh fading case. Finally, for Nakagami fading the capacity is found to decrease by 50 percent as the fading parameter is reduced to 0.5. The performance of a cellular frequency-hopped spread-spectrum multiple access system is studied under an indoor environment. It is demonstrated how the system capacity, given in terms of the number of users per cell, is affected by the number of cells in the system. Also, the influence of the delay spread, which is the result of multipath propagation, is investigated. The analysis focuses on a worst-case scenario where a user receives both the desired and interfering signals with equal power levels. This scenario applies to both the downlink and the uplink. It is shown that the system capacity is reduced drastically as the number of adjacent interfering cells increases from one to three. Previous work concerning the indoor multipath propagation assumed that the number of paths is fixed, the path delays are uniformly distributed, and the path gains are equal. In this dissertation, a more realistic channel model derived from actual impulse response measurements by Saleh and Valenzuela is employed. The model consists of clusters of rays with constant cluster and ray arrival rates and power-delay time constants. The system performance is shown to be affected strongly by the change in the power-delaytime constants, yet only slightly influenced by the variation in the arrival rates of the rays and clusters. In addition, the degradation in the system performance due to the delay spread becomes more severe as the transmission rate increases.

Download or read book Government Reports Announcements Index written by and published by . This book was released on 1984-09 with total page 592 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Wireless Communications written by Andrea Goldsmith and published by Cambridge University Press. This book was released on 2005-08-08 with total page 674 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wireless technology is a truly revolutionary paradigm shift, enabling multimedia communications between people and devices from any location. It also underpins exciting applications such as sensor networks, smart homes, telemedicine, and automated highways. This book provides a comprehensive introduction to the underlying theory, design techniques and analytical tools of wireless communications, focusing primarily on the core principles of wireless system design. The book begins with an overview of wireless systems and standards. The characteristics of the wireless channel are then described, including their fundamental capacity limits. Various modulation, coding, and signal processing schemes are then discussed in detail, including state-of-the-art adaptive modulation, multicarrier, spread spectrum, and multiple antenna techniques. The concluding chapters deal with multiuser communications, cellular system design, and ad-hoc network design. Design insights and tradeoffs are emphasized throughout the book. It contains many worked examples, over 200 figures, almost 300 homework exercises, over 700 references, and is an ideal textbook for students.

Download or read book Multi Carrier and Spread Spectrum Systems written by K. Fazel and published by John Wiley & Sons. This book was released on 2004-02-06 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt: Frequency spectrum is a limited and valuable resource for wireless communications. A good example can be observed among network operators in Europe for the prices to pay for UMTS-frequency bands. Therefore, the first goal when designing future wireless communication systems (e.g. 4G - fourth generation) has to be the increase in spectral efficiency. The development in digital communications in the past years has enabled efficient modulation and coding techniques for robust and spectral efficient data, speech, audio and video transmission. These are the multi-carrier modulation (e.g. OFDM) and the spread spectrum technique (e.g. DS-CDMA), where OFDM was chosen for broadcast applications (DVB, DAB) as well as for broadband wireless indoor standards (ETSI HIPERLAN-II, IEEE-802.11) and the DS-CDMA was selected in mobile communications (IS-95, third generation mobile radio systems world wide, UMTS/IMT 2000). Since 1993 various combinations of multi-carrier (MC) modulation and the spread spectrum (SS) technique have been introduced and the field of MC-SS communications has become an independent and important research topic with increasing activities. New application fields have been proposed such as high rate cellular mobile, high rate wireless indoor and LMDS. It has been shown that MC-SS offers the high spectral efficiency, robustness and flexibility that is required for the next generation systems. Meanwhile, different alternative hybrid schemes such as OFDM/OFDMA, MC-TDMA, etc. have been deeply analysed and adopted in different international standards (ETSI-BRAN, IEEE-802 & MMAC). Multi-Carrier & Spread-Spectrum: Analysis of Hybrid Air Interfaces draws together all of the above mentioned hybrid schemes therefore providing a greatly needed resource for system engineers, telecommunication designers and researchers in order to enable them to develop, build and deploy several schemes based on MC-transmission for the next generation systems (which will be an integration of broadband multimedia services covering both 4G mobile and fixed wireless systems). * Offers a complete treatment of multi-carrier, spread-spectrum (SS) and time division multiplexing (TDM) techniques * Provides an in-depth insight into hybrid multiple access techniques based on multi-carrier (MC) transmission * Presents numerous hybrid multiple access and air interface architectures including OFDM/CDMA, MC-CDMA, MC-DS-CDMA and MT-CDMA * Covers new techniques such as space-time coding and software radio Telecommunications engineers, hardware & software system designers and researchers as well as students, lecturers and technicians will all find this an invaluable addition to their bookshelf.

Download or read book Channel Coding Techniques for Wireless Communications written by K. Deergha Rao and published by Springer Nature. This book was released on 2019-11-22 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discusses the latest channel coding techniques, MIMO systems, and 5G channel coding evolution. It provides a comprehensive overview of channel coding, covering modern techniques such as turbo codes, low-density parity-check (LDPC) codes, space–time coding, polar codes, LT codes, and Raptor codes as well as the traditional codes such as cyclic codes, BCH, RS codes, and convolutional codes. It also explores MIMO communications, which is an effective method for high-speed or high-reliability wireless communications. It also examines the evolution of 5G channel coding techniques. Each of the 13 chapters features numerous illustrative examples for easy understanding of the coding techniques, and MATLAB-based programs are integrated in the text to enhance readers’ grasp of the underlying theories. Further, PC-based MATLAB m-files for illustrative examples are included for students and researchers involved in advanced and current concepts of coding theory.

Download or read book Principles of Mobile Communication written by Gordon L. Stüber and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 670 pages. Available in PDF, EPUB and Kindle. Book excerpt: Principles of Mobile Communication provides an authoritative treatment of the fundamentals of mobile communications, one of the fastest growing areas of the modern telecommunications industry. The book stresses the fundamentals of mobile communications engineering that are important for the design of any mobile system. Less emphasis is placed on the description of existing and proposed wireless standards. This focus on fundamental issues should be of benefit not only to students taking formal instruction but also to practising engineers who are likely to already have a detailed familiarity with the standards and are seeking to deepen their knowledge of this important field. The book stresses mathematical modeling and analysis, rather than providing a qualitative overview. It has been specifically developed as a textbook for graduate level instruction and a reference book for practising engineers and those seeking to pursue research in the area. The book contains sufficient background material for the novice, yet enough advanced material for a sequence of graduate level courses. Principles of Mobile Communication treats a variety of contemporary issues, many of which have been treated before only in the journals. Some material in the book has never appeared before in the literature. The book provides an up-to-date treatment of the subject area at a level of detail that is not available in other books. Also, the book is unique in that the whole range of topics covered is not presently available in any other book. Throughout the book, detailed derivations are provided and extensive references to the literature are made. This is of value to the reader wishing to gain detailed knowledge of a particular topic.

Download or read book Digital Communications written by John G. Proakis and published by . This book was released on 2008-01 with total page 1150 pages. Available in PDF, EPUB and Kindle. Book excerpt: Digital Communications is a classic book in the area that is designed to be used as a senior or graduate level text. The text is flexible and can easily be used in a one semester course or there is enough depth to cover two semesters. Its comprehensive nature makes it a great book for students to keep for reference in their professional careers. This all-inclusive guide delivers an outstanding introduction to the analysis and design of digital communication systems. Includes expert coverage of new topics: Turbocodes, Turboequalization, Antenna Arrays, Digital Cellular Systems, and Iterative Detection. Convenient, sequential organization begins with a look at the history and classification of channel models and builds from there.