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Articles 1 - 20 of 20
Full-Text Articles in Engineering
Improving Noise Immunity And Efficiency Using High-Precision Iterative Codes, Sherzod Shukhratovich Atadjanov, Aziza Ahmadjanovna Tursunova
Improving Noise Immunity And Efficiency Using High-Precision Iterative Codes, Sherzod Shukhratovich Atadjanov, Aziza Ahmadjanovna Tursunova
Bulletin of TUIT: Management and Communication Technologies
The article discusses the issues of ensuring noise immunity in digital broadcasting systems, shows the importance of the transition to the optimal code and the need to use it in the field of noiseless coding in various areas of telecommunication transmission and reception of digital signals. The previous algorithms and error-correcting coding methods based on the Gray code, which are used in multi-level digital broadcast modulation schemes to minimize the intensity of bit errors, are highlighted. A model of error-correcting coding by the Gray method and methods for estimating the probability of error for the Gray code are presented. Based …
H.264 Video Decoder Implemented On Fpgas Using 3×3 And 2×2 Networks-On-Chip, Ian Barge, Cristinel Ababei
H.264 Video Decoder Implemented On Fpgas Using 3×3 And 2×2 Networks-On-Chip, Ian Barge, Cristinel Ababei
Electrical and Computer Engineering Faculty Research and Publications
In this paper, we present the design and verification of the H.264 video decoder algorithm on FPGAs. The primary difference compared to previously reported designs is that the communication between the decoder modules is done via a network-on-chip in our case. The proposed design is a complete system level hardware design described in VHDL and Verilog. We report experimental results for two different implementations. The first implementation uses a 3×3 network-on-chip and is validated on the DE4 development board, which uses Altera's Stratix IV GX FPGA chip. The second implementation uses a 2×2 network-on-chip and is validated on the Cyclone …
Capacity Of Sum-Networks For Different Message Alphabets, Ardhendu Tripathy, Aditya Ramamoorthy
Capacity Of Sum-Networks For Different Message Alphabets, Ardhendu Tripathy, Aditya Ramamoorthy
Ardhendu Tripathy
A sum-network is a directed acyclic network in which all terminal nodes demand the `sum' of the independent information observed at the source nodes. Many characteristics of the well-studied multiple-unicast network communication problem also hold for sum-networks due to a known reduction between instances of these two problems. Our main result is that unlike a multiple unicast network, the coding capacity of a sum-network is dependent on the message alphabet. We demonstrate this using a construction procedure and show that the choice of a message alphabet can reduce the coding capacity of a sum-network from 1 to close to 0.
Sum-Networks From Undirected Graphs: Construction And Capacity Analysis View Document, Ardhendu Tripathy, Aditya Ramamoorthy
Sum-Networks From Undirected Graphs: Construction And Capacity Analysis View Document, Ardhendu Tripathy, Aditya Ramamoorthy
Ardhendu Tripathy
We consider a directed acyclic network with multiple sources and multiple terminals where each terminal is interested in decoding the sum of independent sources generated at the source nodes. We describe a procedure whereby a simple undirected graph can be used to construct such a sum-network and demonstrate an upper bound on its computation rate. Furthermore, we show sufficient conditions for the construction of a linear network code that achieves this upper bound. Our procedure allows us to construct sum-networks that have any arbitrary computation rate p/q (where p, q are non-negative integers). Our work significantly generalizes a previous approach …
Spectral Efficiency Of Wireless Networks With Multi-Antenna Base Stations And Spatially Distributed Nodes, Siddhartan Govindasamy, Daniel Bliss, David Staelin
Spectral Efficiency Of Wireless Networks With Multi-Antenna Base Stations And Spatially Distributed Nodes, Siddhartan Govindasamy, Daniel Bliss, David Staelin
Siddhartan Govindasamy
We analyze networks with wireless nodes distributed randomly in space, transmitting simultaneously in the same channel to their nearest base-stations using a simple power control algorithm. Base-stations are on a hexagonal grid and have N optimally-phased antennas. We derive the asymptotic mean upstream spectral efficiency(validated by simulation) as a function of N, wireless-node density, base-station separation, and path-loss-exponent which controls signal attenuation with distance. These results indicate that mean per-link spectralefficiency is constant if the number of receive antennas or density of base-stations is increased linearly withwireless node density. They also improve our understanding of systems like city-wide wireless Internet …
Floating-Gate Techniques For Assessing Mismatch, Bradley Minch
Floating-Gate Techniques For Assessing Mismatch, Bradley Minch
Bradley Minch
I discuss the importance of capacitor matching in the context of using charge stored on floating-gate MOS (FGMOS) transistors to compensate for transistor mismatch in analog circuits. I describe a simple technique that only involves static measurements for assessing the relative mismatch between capacitors. I also show experimental measurements of capacitor mismatch for small capacitors fabricated in 1.2-μm and 0.35-μm double-poly it n-well CMOS process that are commonly available.
New Coding/Decoding Techniques For Wireless Communication Systems, Yonas Gebregziabher Debessu
New Coding/Decoding Techniques For Wireless Communication Systems, Yonas Gebregziabher Debessu
LSU Doctoral Dissertations
Wireless communication encompasses cellular telephony systems (mobile communication), wireless sensor networks, satellite communication systems and many other applications. Studies relevant to wireless communication deal with maintaining reliable and efficient exchange of information between the transmitter and receiver over a wireless channel. The most practical approach to facilitate reliable communication is using channel coding. In this dissertation we propose novel coding and decoding approaches for practical wireless systems. These approaches include variable-rate convolutional encoder, modified turbo decoder for local content in Single-Frequency Networks, and blind encoder parameter estimation for turbo codes. On the other hand, energy efficiency is major performance issue …
Space-Time Coding With Offset Modulations, N. Thomas Nelson
Space-Time Coding With Offset Modulations, N. Thomas Nelson
Theses and Dissertations
In this dissertation it is shown that the telemetry versions of Feher-patented QPSK (FQPSK-JR) and shaped offset QPSK (SOQPSK-TG) can be interpreted as both cross-correlated, trellis-coded quadrature modulation (XTCQM) and continuous phase modulation (CPM). Based on these representations, both modulations can be detected with near optimal bit error rate performance using a common detector that is formulated as either an XTCQM detector, a traditional CPM detector, or a pulse amplitude modulation (PAM) detector (due to the PAM decomposition of the CPM representations of these modulations). In addition it is shown that the complexity of the XTCQM detector for SOQPSK-TG can …
A Fast Full-Search Adaptive Vector Quantizer For Video Coding, Scott E. Budge, Christian B. Peel
A Fast Full-Search Adaptive Vector Quantizer For Video Coding, Scott E. Budge, Christian B. Peel
Electrical and Computer Engineering Faculty Publications
This paper presents a novel VQ structure which provides very good quality encoding for video sequences and exploits the computational savings gained from a fast-search algorithm. It uses an adaptive-search, variable-length encoding method which allows for very fast matching of a wide range of transmission rates. Both the encoding quality and the computational benefits from the fast-search algorithm are presented. Simulations show that full-search tree residual VQ (FTRVQ) can provide up to 3 dB improvement over a similar RVQ encoder on video sequences.
A Statistical Solution To A Text Decoding Challenge Problem, Xindi Cai, Rui Xu, Donald C. Wunsch, V. A. Samaranayake
A Statistical Solution To A Text Decoding Challenge Problem, Xindi Cai, Rui Xu, Donald C. Wunsch, V. A. Samaranayake
Electrical and Computer Engineering Faculty Research & Creative Works
Given an encoded unknown text message in the form of a three dimensional spatial series generated by the use of four smooth nonlinear functions, we use a method based on simple statistical reasoning to pick up samples for rebuilding the four functions. The estimated functions are then used to decode the sequence. The experimental results show that our method gives a nearly perfect decoding, enabling us to submit a 100% accurate solution to the IJCNN challenge problem
Multilevel Coded Modulation For Unequal Error Protection And Multistage Decoding—Part Ii: Asymmetric Constellations, Motohiko Isaka, Marc P. C. Fossorier, Robert H. Morelos-Zaragoza, Shu Lin, Hideki Imai
Multilevel Coded Modulation For Unequal Error Protection And Multistage Decoding—Part Ii: Asymmetric Constellations, Motohiko Isaka, Marc P. C. Fossorier, Robert H. Morelos-Zaragoza, Shu Lin, Hideki Imai
Faculty Publications
In this paper, multilevel coded asymmetric modulation with multistage decoding and unequal error protection (UEP) is discussed. These results further emphasize the fact that unconventional signal set partitionings are more promising than traditional (Ungerboeck-type) partitionings, to achieve UEP capabilities with multilevel coding and multistage decoding. Three types of unconventional partitionings are analyzed for asymmetric 8-PSK and 16-QAM constellations over the additive white Gaussian noise channel to introduce design guidelines. Generalizations to other PSK and QAM type constellations follow the same lines. Upper bounds on the bit-error probability based on union bound arguments are first derived. In some cases, these bounds …
Multilevel Coded Modulation For Unequal Error Protection And Multistage Decoding—Part I: Symmetric Constellations, Robert H. Morelos-Zaragoza, Marc P. C. Fossorier, Shu Lin, Hideki Imai
Multilevel Coded Modulation For Unequal Error Protection And Multistage Decoding—Part I: Symmetric Constellations, Robert H. Morelos-Zaragoza, Marc P. C. Fossorier, Shu Lin, Hideki Imai
Faculty Publications
In this paper, theoretical upper bounds and computer simulation results on the error performance of multilevel block coded modulations for unequal error protection (UEP) and multistage decoding are presented. It is shown that nonstandard signal set partitionings and multistage decoding provide excellent UEP capabilities beyond those achievable with conventional coded modulation. The coding scheme is designed in such a way that the most important information bits have a lower error rate than other information bits. The large effective error coefficients, normally associated with standard mapping by set partitioning, are reduced by considering nonstandard partitionings of the underlying signal set. The …
On The Error Performance Of 8-Vsb Tcm Decoder For Atsc Terrestrial Broadcasting Of Digital Television, Dojun Rhee, Robert H. Morelos-Zaragoza
On The Error Performance Of 8-Vsb Tcm Decoder For Atsc Terrestrial Broadcasting Of Digital Television, Dojun Rhee, Robert H. Morelos-Zaragoza
Faculty Publications
The error performance of various 8-VSB TCM decoders for reception of terrestrial digital television is analyzed. In previous work, 8-state TCM decoders were proposed and implemented for terrestrial broadcasting of digital television. In this paper, the performance of a 16-state TCM decoder is analyzed and simulated. It is shown that not only a 16-state TCM decoder outperforms one with 8-states, but it also has much smaller error coefficients.
Results Using An Alternative Approach To Channel Equalization Using A Pattern Classification Strategy, Frank M. Caimi, Gamal A. Hassan
Results Using An Alternative Approach To Channel Equalization Using A Pattern Classification Strategy, Frank M. Caimi, Gamal A. Hassan
Electrical Engineering and Computer Science Faculty Publications
In underwater acoustic communication, (ACOMMs), ocean surface and bottom conditions create multi path propagation's for the transmitted signal that result in Inter symbol Interference (ISI) at the receiver. Generally, Equalization, Diversity IBeam forming, and Channel Coding are three independent techniques that are used to improve received signal quality. Equalization compensates for ISI created by a band-limited, time-dispersive channel through implementation of specialized filtering schemes within the receiver. The coefficients of the equalizer need to be continuously adjusted to compensate for the variability in the channel. Since the number of states required by the equalizer (or beam former) is finite, and …
Concatenated Multilevel Coded Modulation Schemes For Digital Satellite Broadcasting, Robert H. Morelos-Zaragoza, Hideki Imai
Concatenated Multilevel Coded Modulation Schemes For Digital Satellite Broadcasting, Robert H. Morelos-Zaragoza, Hideki Imai
Faculty Publications
The error performance of bandwith-efficient concatenated multilevel coded modulation (MCM) schemes for digital satellite broadcasting is analyzed. Nonstandard partitioning, multistage decoding, and outer Reed-Solomon (RS) codes are employed to provided unequal error protection capabilities.
Multilevel Block Coded Modulation With Unequal Error Protection, Robert H. Morelos-Zaragoza, Marc P. C. Fossorier, Shu Lin, Hideki Imai
Multilevel Block Coded Modulation With Unequal Error Protection, Robert H. Morelos-Zaragoza, Marc P. C. Fossorier, Shu Lin, Hideki Imai
Faculty Publications
Multilevel block coded modulation (BCM) schemes with unequal error protection (UEP) are investigated. These schemes are based on unconventional set partitions that greatly reduce the error coefficients associated with multi-stage decoding of conventional BCM, at the expense of smaller intra-set distances.
Variable-Complexity Trellis Decoding Of Binary Convolutional Codes, David W. Matolak, S. G. Wilson
Variable-Complexity Trellis Decoding Of Binary Convolutional Codes, David W. Matolak, S. G. Wilson
Faculty Publications
Considers trellis decoding of convolutional codes with selectable effort, as measured by decoder complexity. Decoding is described for single parent codes with a variety of complexities, with performance "near" that of the optimal fixed receiver complexity coding system. Effective free distance is examined. Criteria are proposed for ranking parent codes, and some codes found to be best according to the criteria are tabulated, Several codes with effective free distance better than the best code of comparable complexity were found. Asymptotic (high SNR) performance analysis and error propagation are discussed. Simulation results are also provided.
Coded Modulation For Satellite Broadcasting, Robert H. Morelos-Zaragoza, Oscar Y. Takeshita, Hideki Imai, Marc P. C. Fossorier, Shu Lin
Coded Modulation For Satellite Broadcasting, Robert H. Morelos-Zaragoza, Oscar Y. Takeshita, Hideki Imai, Marc P. C. Fossorier, Shu Lin
Faculty Publications
In this paper, three-level block coded 8-PSK modulations, suitable for satellite broadcasting of digital TV signals, are presented. A design principle to achieve unequal error protection is introduced. The coding scheme is designed in such a way that the information bits carrying the basic definition TV signal have a lower error rate than the high definition information bits. The large error coefficients, formally associated with standard mapping by set partitioning, are reduced by considering a nonstandard partition of an 8-PSK signal set. The bits-to-signal mapping induced by this partition allows the use of suboptimal low-complexity soft-decision decoding of binary block …
Qpsk Block-Modulation Codes For Unequal Error Protection, Robert H. Morelos-Zaragoza, Shu Lin
Qpsk Block-Modulation Codes For Unequal Error Protection, Robert H. Morelos-Zaragoza, Shu Lin
Faculty Publications
Unequal error protection (UEP) codes find applications in broadcast channels, as well as in other digital communication systems, where messages have different degrees of importance. Binary linear UEP (LUEP) codes combined with a Gray mapped QPSK signal set are used to obtain new efficient QPSK block-modulation codes for unequal error protection. Several examples of QPSK modulation codes that have the same minimum squared Euclidean distance as the best QPSK modulation codes, of the same rate and length, are given. In the new constructions of QPSK block-modulation codes, even-length binary LUEP codes are used. Good even-length binary LUEP codes are obtained …
Unequal Error Protection Qpsk Modulation Codes, Robert H. Morelos-Zaragoza, Shu Lin
Unequal Error Protection Qpsk Modulation Codes, Robert H. Morelos-Zaragoza, Shu Lin
Faculty Publications
The authors use binary linear UEP (LUEP) codes, in combination with a QPSK signal set and Gray mapping, to obtain new efficient block QPSK modulation codes with unequal minimum squared Euclidean distances. They give several examples of codes that have the same minimum squared Euclidean distance as the best QPSK modulation codes of the same rate and length. A new suboptimal two-stage soft-decision decoding is applied to LUEP QPSK modulation codes.