Download or read book Performance Analysis of Wireless LAN Signals Transmitted Over a Ricean Fading Channel in a Pulsed Noise Interference Environment written by Evaggelos Spyrou and published by . This book was released on 2004-09 with total page 91 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis examines the performance of the waveforms specified by the IEEE 802.11a wireless local area network standard when the signal is transmitted over a Ricean fading channel with AWGN and pulsed noise interference. The pulsed interference is assumed to have constant average power and is either fading or nonfading. The probability of bit error is conditional on the received signal to noise power ratio, which is modeled as a random variable. The probability density function of this random variable is obtained either analytically or numerically for each modulation type, and the probability of bit error is evaluated as the expected value of the conditional probability. In one case, use is made of a new technique for the numerical inverse of the Laplace transform in order to evaluate numerically the signal to noise ratio probability density function. Due to the complexity of the analysis when both the signal and the interference are subject to Ricean fading, the analysis was simplified by assuming Ricean signal fading with Rayleigh interference fading and vice versa. The results of the analysis show that performance is affected by the degree of signal fading and also depends on the pulsed interference duty cycle. The signal to interference power ratio affects the way performance depends on these two factors.
Download or read book Performance Analysis of Variable Code Rate Signals Transmitted Over Frequency Nonselective Slowly Fading Channels in a Pulse Interference Environment written by and published by . This book was released on 2005 with total page 99 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wireless systems, including wireless local area networks (WLAN) and cellular networks, are increasingly being used for both commercial and military applications. For military applications, it is important to analyze the effect of interference on wireless communications systems. The objective of this research is to investigate the performance of variable code rate signals transmitted over frequency-nonselective, slowly fading channels in a worst case, pulse-noise interference environment. Both binary phase-shift keying (BPSK) and noncoherently detected binary frequency-shift keying (NCBFSK) are considered. System performance with both Viterbi hard decision decoding (HDD) and soft decision decoding (SDD) is analyzed for additive white Gaussian noise (AWGN) alone and for AWGN plus pulse-noise interference for various receiver types and conditions of channel fading. The effect of varying the code rate, both for HDD and SDD, is examined. The amplitude of the signal power a(exp 2)/(sub c) is modeled as a random variable, and the channel is modeled as either Rayleigh fading or Ricean fading, depending on the modulation under consideration.
Download or read book Performance Analysis of the Effect of Pulsed Noise Interference on WLAN Signals Transmitted Over a Nakagami Fading Channel written by Andreas Tsoumanis and published by . This book was released on 2004-03 with total page 87 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis examines the performance of wireless local area network (WLAN) signals, specifically, the signal of IEEE 802,1 la standard, The signal is subject to pulsed noise jamming, when either the desired signal alone or the desired signal and the jamming signal are subject to Nakagami fading, As expected, the implementation of forward error correction (FEC) coding with soft decision decoding (SDD) and maximum- likelihood detection improves performance as compared to uncoded signals, In addition, the combination of maximum- likelihood detection and error connection coding renders pulsed-noise jamming ineffective as compared to bandage noise jamming, When the jamming signal encounters fading as well, we assume that the average jamming power is much greater than the AWGN power, For uncoded signals, a jamming signal that experiences fading actually improves performance when the parameter of the information signal m(s) is less than or equal to one, Surprisingly, for larger values of m(s) a jamming signal that experiences fading works in favor of the information signal only for small signal-to- interference ratio (SIR), When SIR is large, performance when the jamming signal experiences fading is worse relative to performance when the jamming signal does not experience fading, For error correction coding with SDD, we investigate only continuous jamming since it is by far the worst-case, Moreover, while we consider a range of fading conditions for the jamming signal, we examine only Rayleigh fading of the information signal, The coded signal, when the jamming signal experiences severe fading, performs better relative to the case when the jamming signal does not experience fading,
Download or read book Performance Analysis of the IEEE 802 11G Waveform Transmitted Over a Fading Channel with Pulse noise Interference written by and published by . This book was released on 2006 with total page 101 pages. Available in PDF, EPUB and Kindle. Book excerpt: The performance of the most promising wireless local area network (WLAN) standards today, IEEE 802.11g, which specifies orthogonal frequency-division multiplexing in order to avoid multi-path effects and at the same time achieve high data rates, was examined in this thesis. We investigated four different receivers and analyzed their performance with Viterbi soft decision decoding when the signal was transmitted over a slow, flat fading Nakagami channel for AWGN only, as well as for AWGN plus pulse-noise interference. The implementation of forward error correction coding with soft decision decoding improves the performance compared to uncoded signal if pulse-noise interference is not present. The scenarios when no side information is available (linear-combining receiver), when perfect side information is available (noise-normalizing receiver), and two alternatives to the noise-normalized receiver with much coarser side information (modified noise-normalized receiver and noise-normalized receiver with normalization error) are examined. All the scenarios are examined for various fading and interference conditions. The performance of the noise-normalized receiver is, as expected, much improved compared to the linear-combining receiver when PNI is present. Finally, the noise-normalized receiver with normalization error achieves the same or better performance than the noise-normalized receiver without the exact interference noise power.
Download or read book Fading and Interference Mitigation in Wireless Communications written by Stefan Panic and published by CRC Press. This book was released on 2013-12-11 with total page 263 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fading and Interference Mitigation in Wireless Communications will help readers stay up to date with recent developments in the performance analysis of space diversity reception over fading channels in the presence of cochannel interference. It presents a unified method for computing the performance of digital communication systems characterized by a variety of modulation and detection types and channel models. The book includes coverage of multichannel reception in various fading environments, influence of cochannel interference, and macrodiversity reception when channels are simultaneously affected by various types of fading and shadowing.
Download or read book Performance Analysis of the IEEE 802 11A WLAN Standard Optimum and Sub Optimum Receiver in Frequency Selective Slowly Fading Nakagami Channels with AWGN and Pulsed Noise Jamming written by Christos Kalogrias and published by . This book was released on 2004-03-01 with total page 169 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this thesis is to investigate the performance of the orthogonal frequency division multiplexing (OFDM) based IEEE 802.11a wireless local area network (WLAN) standard receiver when the signal is transmitted over a frequency selective, slow fading Nakagami channel in a worst case, pulse-noise jamming environment. The different combinations of modulation type (both binary and non-binary modulation) and convolutional code rate specified by the WLAN standard are examined. Receiver performance with Viterbi soft decision decoding (SDD) is analyzed for additive white Gaussian noise (AWGN) alone as well as for AWGN plus pulse-noise jamming (PNJ). The performance of the IEEE 802.11a WLAN standard receiver is examined both for the scenario in which perfect side information is assumed (optimum receiver) and when it is not (sub-optimum receiver). For the sub-optimum receiver scenario, the receiver performance is examined both when noise-normalization is utilized and when only linear combining is utilized. The analysis indicates that the receiver performance is severely affected by the pulse-noise jamming environment for the linear combining scenario; however, the sub-optimum receiver performance is significantly improved when noise-normalization is implemented. (2 tables, 74 figures, 11 refs.)
Download or read book Performance of IEEE 802 11a Wireless LAN Standard Over Frequency Selective Slowly Fading Nakagami Channels in a Pulsed Jamming Environment written by Irfan Kosa and published by . This book was released on 2002-12-01 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wireless local area networks (WLAN) are increasingly important in meeting the needs of the next generation broadband wireless communication systems for both commercial and military applications. In 1999, the Institute of the Electrical and Electronics Engineers (IEEE) 802.11a working group approved a standard for a 5 GHz band WLAN that supports a variable bit rate from 6 to 54 Mbps, and orthogonal frequency-division multiplexing (OFDM) was chosen because of its well-known ability to avoid multipath effects while achieving high data rates by combining a high order sub-carrier modulation with a high rate convolutional code. This thesis investigates the performance of the OFDM based IEEE. 802. 11a WLAN standard in frequency-selective, slowly fading Nakagami channels in a pulsed-noise jamming environment. Contrary to expectations, the signal-to-interference ratio (SIR) required to achieve a specific P does not monotonically decrease when the bit rate decreases. Furthermore, the results show that the performance is improved significantly by adding convolutional coding with Viterbi% decoding, and thus highlights the importance of forward error correction (FEC) coding to the performance of wireless communications systems.
Download or read book Performance of the IEEE 802 11a Wireless Lan Standard Over Frequency Selective Slow Ricean Fading Channels written by Chi-han Kao and published by . This book was released on 2002-09-01 with total page 115 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the rapidly growing demand for more reliable and higher data rate wireless communications, the Institute of the Electrical and Electronics Engineers (IEEE) 802.11 working group approved a standard for 5-GHz band, wireless local area networks (WLAN) in 1999. This standard, IEEE 802.lla, supports data rates from 6 up to 54 Mbps and uses orthogonal frequency division multiplexing (OFDM) for transmission in indoor wireless environments. This thesis examines the performance of the IEEE 802.lla standard for different combinations of sub-carrier modulation type and code rate and determines the signal-to-noise ratio required to obtain a probability of bit error P(b) of 10 sub -5. The channel is modeled as frequency-selective, slow, Ricean fading channel with additive white Gaussian noise (AWGN). Contrary to expectations, for the combinations of sub-carrier modulation type and code rate utilized by the IEEE 802. 11a standard, some of the higher data rate combinations outperform some of the lower data rate combinations. On the other hand, the results also show significant coding gain when applying convolutional coding with Viterbi decoding, and hence highlight the importance of forward error correction (FEC) coding to the performance of wireless communications systems.
Download or read book Fundamentals of Wireless Communication written by David Tse and published by Cambridge University Press. This book was released on 2005-05-26 with total page 598 pages. Available in PDF, EPUB and Kindle. Book excerpt: This textbook takes a unified view of the fundamentals of wireless communication and explains cutting-edge concepts in a simple and intuitive way. An abundant supply of exercises make it ideal for graduate courses in electrical and computer engineering and it will also be of great interest to practising engineers.
Download or read book Electrical Electronics Abstracts written by and published by . This book was released on 1997 with total page 1904 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Science and Technology Assistant Ed K R Rider F R Taylor written by and published by . This book was released on 1966 with total page 483 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Wireless Communication Over Fading Channels with Imperfect Channel Estimates written by Amir Ali Basri and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Digital Communication over Fading Channels written by Marvin K. Simon and published by John Wiley & Sons. This book was released on 2005-02-11 with total page 936 pages. Available in PDF, EPUB and Kindle. Book excerpt: The four short years since Digital Communication over Fading Channels became an instant classic have seen a virtual explosion of significant new work on the subject, both by the authors and by numerous researchers around the world. Foremost among these is a great deal of progress in the area of transmit diversity and space-time coding and the associated multiple input-multiple output (MIMO) channel. This new edition gathers these and other results, previously scattered throughout numerous publications, into a single convenient and informative volume. Like its predecessor, this Second Edition discusses in detail coherent and noncoherent communication systems as well as a large variety of fading channel models typical of communication links found in the real world. Coverage includes single- and multichannel reception and, in the case of the latter, a large variety of diversity types. The moment generating function (MGF)-based approach for performance analysis, introduced by the authors in the first edition and referred to in literally hundreds of publications, still represents the backbone of the book's presentation. Important features of this new edition include: * An all-new, comprehensive chapter on transmit diversity, space-time coding, and the MIMO channel, focusing on performance evaluation * Coverage of new and improved diversity schemes * Performance analyses of previously known schemes in new and different fading scenarios * A new chapter on the outage probability of cellular mobile radio systems * A new chapter on the capacity of fading channels * And much more Digital Communication over Fading Channels, Second Edition is an indispensable resource for graduate students, researchers investigating these systems, and practicing engineers responsible for evaluating their performance.
Download or read book An Analysis of Electromagnetic Interference EMI of Ultra Wideband UWB and IEEE 802 11A Wireless Local Area Network WLAN Employing Orthogonal Frequency Division Multiplexing OFDM written by Juan Lopez (Jr.) and published by . This book was released on 2004-03-01 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: Military communications require the rapid deployment of mobile, high- bandwidth systems. These systems must provide anytime, anywhere capabilities with minimal interference to existing military, private, and commercial communications. Ultra Wideband (UWB) technology is being advanced as the next generation radio technology and has the potential to revolutionize indoor wireless communications. The ability of UWB to mitigate multipath fading, provide high-throughput data rates (e.g., greater than 100 Mbps), provide excellent signal penetration (e.g., through walls), and low implementation costs makes it an ideal technology for a wide range of private and public sector applications. Preliminary UWB studies conducted by The Institute for Telecommunications Science (ITS) and the Defense Advanced Research Projects Agency (DARPA) have discovered that potential exists for harmful interference to occur. While these studies have provided initial performance estimates, the interference effects of UWB transmissions on coexisting spectral users are largely unknown. This research characterizes the electromagnetic interference (EMI) effects of UWB on the throughput performance of an IEEE 802.11a ad-hoc network. Radiated measurements in an anechoic chamber investigate interference performance using three modulation schemes (BPSK, BPPM, and OOK) and four pulse repetition frequencies over two Unlicensed National Information Infrastructure (U-NII) channels. Results indicate that OOK and BPPM can degrade throughput performance by up to 20% at lower pulse repetition frequencies (PRFs) in lower U-NII channels. Minimal performance degradation (less than one percent) due to interference was observed for BPSK at the lower PRFs and higher U-NII channels.
Download or read book Wireless LAN Systems written by Asunción Santamaría and published by Artech House Publishers. This book was released on 1994 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt: This guide to wireless LAN systems describes the current technologies, spells out the pros and cons of each, and offers implementation insights that can save your company valuable installation time, money, and effort. It provides in-depth analyses of all aspects of indoor LAN wireless transmission techniques via RF and infrared waves.
Download or read book Performance Analysis and Techniques for Wireless Systems with Unmanaged and Managed Interference written by Ahmed O. D. Ali and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In the past few decades, the world has witnessed enormous advances in wireless communication systems introducing unprecedented applications and services. Such advances brought the idea of Internet of Things (IoT) to life, where almost every object is interconnected to each other through the existing Internet infrastructure. This results in enormous increase in the number of wireless devices sharing the same medium and bandwidth in different networks. Consequently, interference generated by such devices is expected to increase drastically, and hence innovative techniques to mitigate such interference have to be investigated. In this dissertation, we investigate the interference in wireless communication networks. The dissertation is divided into two parts dealing with unmanaged and managed interference, respectively. In the first part, we investigate the second order statistics of a system consisting of a single receiver with multiple antennas, a single desired user and multiple interferers. Specifically, we derive exact closed-form level-crossing rate (LCR) expressions for such a system under different spatial correlation assumptions which, to the best of our knowledge, are reported for the first time in literature. We also derive an approximate LCR expression in the spatially uncorrelated receiver to get better insight. Moreover, we investigate the effect of the different system’s parameters on the LCR. Then, we introduce two applications where in the first we use these new expressions to evaluate the system’s packet error rate (PER). The second application uses the derived LCR expressions in Finite-State Markov Chain (FSMC) modeling to evaluate the system’s throughput when deploying Automatic Repeat Request (ARQ). We also formulate an optimization problem where we find the packet length maximizing the system’s throughput. In the second part of the dissertation, we deal with managed interference where we use joint transmit and receive beamforming to mitigate the interference for frequency selective fading channels. In particular, we propose exploiting the guard intervals, e.g., the cyclic prefix or the zero-padding intervals, to increase the degrees of freedom (DoFs) used, and consequently the sum rate of the system through applying interference alignment (IA) iterative schemes. We derive an upper bound on the number of allowable DoFs per user and evaluate the system’s sum rate and compare it with other IA schemes reported in literature. We also investigate the effect of partial channel state information (CSI) on the performance of such a system and propose a robust beamforming transceiver design. We also derive an approximate expression for the system’s average sum stream rate when exploiting the guard interval in transmission in presence of CSI error. Furthermore, we attempt to address the question whether it is better to align the interference or orthogonalize the transmitted signals through investigating an uplink cellular system deploying IA in presence of CSI uncertainty. In this system, we derive closed-form lower and upper bounds and approximation for the average cell rate and use the derived expressions to determine analytically the operation regions of IA relative to orthogonal multiple access (OMA) schemes. Finally, we propose a hybrid IA/OMA transmission scheme to improve the network performance.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt:
