Download or read book Performance Analysis of a Variable Data Rate TCM Waveform Transmitted Over a Channel with AWGN and Pulse noise Interference written by and published by . This book was released on 2007 with total page 101 pages. Available in PDF, EPUB and Kindle. Book excerpt: Trellis-coded modulation (TCM) is a technique where forward error correction coding and modulation are treated in a single operation without increasing the channel bandwidth. In this thesis the performance of a variable data rate TCM waveform transmitted over a channel is investigated. In general, TCM systems with rate 1/2 and rate 2/3 convolutional codes and quadrature-shift keying (QPSK) and 8-phase-shift keying (PSK) modulation, respectively, are considered. The data rate of the later TCM system is 50% faster than that of the former. Two cases are considered. In the first case, the number of memory elements K remains constant as the code rate increases. In the second case, the number of memory elements increases linearly with code rate, so that the total number of memory elements for 8-PSK, r=2/3 TCM is given by 1/ 2 2 K K =, where 1/ 2 K is the number of memory elements for the QPSK, r=1/2 convolutionally encoded TCM system. The effects of pulse-noise interference (PNI) in addition to additive white Gaussian noise (AWGN) are considered. It was found that both TCM systems have significant resistance to PNI when K is large enough.
Download or read book Performance Analysis of an Alternative to Trellis Coded Modulation for Waveforms Transmitted Over a Channel with Pulse Noise Interference written by and published by . This book was released on 2008 with total page 41 pages. Available in PDF, EPUB and Kindle. Book excerpt: The performance of a communication system having almost the same spectral efficiency as a trellis coded modulation (TCM) system with r = 2/3 convolutional encoding and 8-ary phase-shift keying (8-PSK) modulation is investigated. TCM is a common solution to the problem of adding forward error correction (FEC) coding without an attendant increase in channel bandwidth. The primary drawback to TCM is that the achievable coding gain is limited by the maximum practical number of states in the convolutional encoder. The alternative system considered uses (63, 37) Reed-Solomon (RS) encoding. The six-bit symbols at the output of the Reed-Solomon encoder undergo serial-to-parallel conversion to two three-bit symbols, which are then independently transmitted on the in-phase (I) and quadrature (Q) component of the carrier using 8-ary biorthogonal keying (8-BOK). This system has a null-to-null bandwidth of 0.993Rb, which is 0.7% smaller than TCM with r = 2/3 convolutional encoding and 8-PSK modulation. The two waveforms are compared for the relatively benign case where additive white Gaussian noise (AWGN) is the only noise present as well as when pulse-noise interference (PNI) is present. It was found that both systems have almost the same performance in AWGN, but with PNI the alternative system has better performance.
Download or read book Performance Analysis of an Alternative Link 16 JTIDS Waveform Transmitted Over a Channel with Pulse Noise Interference written by and published by . This book was released on 2008 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Joint Tactical Information Distribution System (JTIDS) is a hybrid frequency-hopped direct sequence spread spectrum system that utilizes a (31, 15) Reed- Solomon (RS) code and cyclical code-shift keying modulation for the data packets, where each encoded symbol consists of five bits. The primary drawback to JTIDS is the limited data rate. In this thesis, an alternative waveform consistent with the existing JTIDS waveform but with twice the data rate is analyzed The system to be considered also uses (31, 15) RS encoding, but each pair of five-bit symbols at the output of the RS encoder undergoes serial-to-parallel conversion to two five-bit symbols, which are then independently transmitted on the in-phase and quadrature component of the carrier using 32-ary orthogonal signals with a diversity of two. In this thesis, only coherent detection is considered. The performance obtained with the alternative JTIDS waveform is compared with the existing JTIDS waveform when only additive white Gaussian noise (AWGN) is present as well as when pulse-noise interference (PNI) is also present Errors-and- erasures decoding (EED), errors-only decoding and perfect side information (PSI) are also considered.
Download or read book Bandwidth Efficient Digital Modulation with Application to Deep Space Communications written by Marvin K. Simon and published by John Wiley & Sons. This book was released on 2005-03-04 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: An important look at bandwidth-efficient modulations with applications to today's Space program Based on research and results obtained at the California Institute of Technology's Jet Propulsion Laboratory, this timely book defines, describes, and then delineates the performance (power and bandwidth) of digital communication systems that incorporate a wide variety of bandwidth-efficient modulations appropriate for the design and implementation of space communications systems. The author compares the performance of these systems in the presence of a number of practical (non-ideal) transmitter and receiver characteristics such as modulator and phase imbalance, imperfect carrier synchronization, and transmitter nonlinearity. Although the material focuses on the deep space applications developed at the Jet Propulsion Laboratory, the presentation is sufficiently broad as to be applicable to a host of other applications dealing with RF communications. An important contribution to the scientific literature, Bandwidth-Efficient Digital Modulation with Application to Deep Space Communications * was commissioned by the JPL Deep Space Communications and Navigation System Center of Excellence * highlights many NASA-funded technical contributions pertaining to deep space communications systems * is a part of the prestigious Deep Space Communications and Navigation Series The Deep Space Communications and Navigation Series is authored by scientists and engineers with extensive experience in astronautics, communications, and related fields. It lays the foundation for innovation in the areas of deep space navigation and communications by disseminating state-of-the-art knowledge in key technologies.
Download or read book Performance Analysis of M QAM with Viterbi Soft Decision Decoding written by Rogerio C. Manso and published by . This book was released on 2003-03 with total page 127 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis derives design tools for determining and improving performances of communication links that use M-QAM coherent demodulators associated with Viterbi soft-decision decoding (SDD) in Additive White Gaussian Noise (AWGN) and Nakagami-m channels. Performance analyses for 16-QAM, 64-QAM, QPSK and BPSK associated with up to three convolutional codes, including the one used by the IEEE 802.11 a standard and the dual-k code, are presented as practical applications. The main tools relate to the analytical derivation of upper bounds of the probability of bit error (Pb) for any M-ary coherent demodulator followed by SDD, a methodology for improving an upper bound of Pb tightening it to realistic data, and the obtaining of the specific beta(d) spectrum for any convolutional code intended to operate with a certain M- symbol modulation. All derivations involve statistical considerations over the AWGN and Nakagami-m channels, as well as in-depth analyses of modulator constellations. The tools and models developed can provide great optimization to bandwidth limited system designs that require high data rates, especially the wireless ones. Consequently, they have great application to many fields of digital communications, such as cellular telephony, wireless networking, satellite links, ship - to- shore and ship-to- ship communications.
Download or read book Waveforms and Receivers for Pulse Amplitude Modulation written by T. Berger and published by . This book was released on 1965 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: Intersymbol interference, additive noise and inexact synchronization, or timing jitter, are three common sources of distortion in data transmission systems. For pulse amplitude modulation communication links, the combination of transmitter waveform and linear receiver which minimizes the over-all mean square error arising from these sources is determined. Formulas are derived which permit one to explore the dependence of system performance on the data rate, the correlation properties of the data, the noise spectrum, the impulse response of the transmission medium and the probability distribution of the timing jitter. Mean square error vs. signal-to -noise ratio performance characteristics of the optimal systems are determined explicitly for several examples. These characteristics are compared both with those of certain suboptimal systems and with the optimal performance theoretically attainable (OPTA) derived from Shannon's theory of rate distortion functions. The optimal PAM systems, which can be interpreted as ideal combinations of infinite memory convolution encoders and decoders, are seen to perform very close to the OPTA for low signal-to-noise ratios. For high signal-to-noise ratios, however, the mean square error of an optimal PAM system decreases as the reciprocal of the signal-to-noise ratios, whereas the OPTA generally decreases exponentially. Accordingly, there exists a potential for realizing significant improvement at high signal-to-noise ratios by resorting to complex, nonlinear coding techniques. (Author).
Download or read book Measurements of Digital Systems in Gaussian Additive Noise and Interference written by John R. Juroshek and published by . This book was released on 1976 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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.
Download or read book Analysis of the Error Performance of Trellis coded Modulations in Rayleigh Fading Channels written by and published by . This book was released on 1989 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: Trellis-coded modulation (TCM), when combined with interleaving, is known to give good error performance in fading channels. Previously, the only analytical guide was an upper bound, which could be very loose over the range of the signal to noise ratio of interest. This paper presents an exact expression for the pairwise error event probability of TCM transmitted over Rayleigh fading channels. It includes PSK and multilevel QAM codes, as well as coherent and partially coherent detection. The paper also studies several coded modulation schemes this way.
Download or read book Digital Data Transmission Tests on Voice Channels written by Urban Sciences, Inc and published by . This book was released on 1977 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Performance Analysis of Turbo Codes Over AWGN and Rayleigh Channels Using Different Interleavers written by Syed Amajad Ali and published by . This book was released on 2001 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sampling Time Jitter written by Seyed Mohammad Seifi and published by . This book was released on 2013 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electrical systems which use voltage transitions to represent timing information suffer from a degrading phenomenon called timing jitter. Sampling time jitter is the deviation of sampling clock from its ideal position. As transmission rates raise above couple of GHz, deviations become significant comparing to signalling interval, jitter becomes a fundamental performance bottleneck. Especially in band-limited communication systems that imperfect sampling times result in Inter-Symbol Interference (ISI) jitter is a very limiting factor to decode correct transmitted data. In this case, jitter timing error translates into amplitude error. At first, the effect of sampling time jitter at the received signal is modelled as an additive noise .This additive noise signal which we call it jitter noise is a coloured noise that also depends on input signal. Expressions for jitter noise correlation factors, its cross- correlation with input signal are derived. These correlations depend on input spectral density, timing jitter characteristic function (Fourier transform of jitter probability density function) and whether timing jitter is white or coloured. In case of first order Gauss-Markov process for sampling time jitter it is observed that in high memory regime (highly correlated timing jitter) the spectral density of additive jitter noise is concentrated around higher frequencies. Exploiting this quality, a spectral shaping scheme is used to improve the performance in terms of Bit Error Rate (BER) for an AWGN channel with discrete input corrupted by sampling time jitter. Simulation results comparing the proposed scheme performance with a minimum distance decoder are provided. As another approach the well-known Viterbi Algorithm is used for decoding same AWGN channel suffering from ISI terms due to sampling jitter. The Viterbi algorithm, which basically is a dynamic programming algorithm, finds the most likely input data and jitter times based on observed output sequence. A quantized version of jitter times is used to be able to work with a finite state trellis and to find likelihoods along the paths of the diagram. Then Bit Error Rate curves for different jitter quantization levels and different impulse response lengths of channel are presented.
Download or read book Simulation and Software Radio for Mobile Communications written by Hiroshi Harada and published by Artech House. This book was released on 2002 with total page 498 pages. Available in PDF, EPUB and Kindle. Book excerpt: This cutting-edge, first-of-its-kind resource gives you a comprehensive understanding of the simulation and evaluation methods used for today's mobile communication systems. Written by two highly regarded experts in the field, the book focuses on the performance of both the physical and protocol layer transmission scheme. It defines and presents several invaluable simulation tools written in MATLAB® code, along with clear examples that explain their use.
Download or read book CW Interference Effects on High Data Rate Transmission Through the ACTS Wideband Channel written by and published by . This book was released on 1996 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fundamentals of Digital Communication written by Upamanyu Madhow and published by Cambridge University Press. This book was released on 2008-03-06 with total page 578 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is a concise presentation of the concepts underlying the design of digital communication systems, without the detail that can overwhelm students. Many examples, from the basic to the cutting-edge, show how the theory is used in the design of modern systems and the relevance of this theory will motivate students. The theory is supported by practical algorithms so that the student can perform computations and simulations. Leading edge topics in coding and wireless communication make this an ideal text for students taking just one course on the subject. Fundamentals of Digital Communications has coverage of turbo and LDPC codes in sufficient detail and clarity to enable hands-on implementation and performance evaluation, as well as 'just enough' information theory to enable computation of performance benchmarks to compare them against. Other unique features include space-time communication and geometric insights into noncoherent communication and equalization.
Download or read book Channel Estimate based Performance Prediction for Coherent Linearly Modulated Wireless Communications Systems written by Thomas L. Staley and published by . This book was released on 1997 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Performance Comparison of Bipolar Alternate Mark Inversion and Conditioned Diphase Waveforms Over Wireline Media written by Guy E. Eller and published by . This book was released on 1977 with total page 103 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report was prepared for the Defense Communications Agency to study the performance of two waveforms competing for implementation in the Defense Communications System. The waveforms, Bipolar Alternate Mark Inversion (BAMI) and Conditioned Diphase (CDtheta), were studied both from a theoretical standpoint and with experimental breadboard hardware designed and built in-house. Theoretical performance curves for both waveforms operating in wideband gaussian noise were developed and the hardware was tested against wideband gaussian noise. The results of testing the waveform over Griffiss AFB cable plant are presented along with computer-generated distributions of data bit errors encountered. The effects and problems involved in recovering timing information from two waveforms are not covered in this report. The results indicate that, with white gaussian noise as the only transmission impairment, the two waveforms perform nearly identically. Their performances are also close when operation is over cables with moderate amounts of intersymbol interference and attenuation. However, when intersymbol interference and attenuation are severe (long calbes, high data rates, and poor-condition cables), BAMI has an advantage of approximately 30 percent, expressed in terms of maximum usable bit rate for a given length of cable. Another conclusion reached was that impulse noise is the limiting impairment of the Griffiss AFB cable plant. (Author).
