Author: Abigail ElcockPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Physical Layer Network Coding Based on Compute-and-Forward
Author: Abigail ElcockChannel Estimation for Physical Layer Network Coding Systems
Author: Feifei GaoPublisher: Springer
ISBN: 3319116681
Category : Computers
Languages : en
Pages : 85
Book Description
This SpringerBrief presents channel estimation strategies for the physical later network coding (PLNC) systems. Along with a review of PLNC architectures, this brief examines new challenges brought by the special structure of bi-directional two-hop transmissions that are different from the traditional point-to-point systems and unidirectional relay systems. The authors discuss the channel estimation strategies over typical fading scenarios, including frequency flat fading, frequency selective fading and time selective fading, as well as future research directions. Chapters explore the performance of the channel estimation strategy and optimal structure of training sequences for each scenario. Besides the analysis of channel estimation strategies, the book also points out the necessity of revisiting other signal processing issues for the PLNC system. Channel Estimation of Physical Layer Network Coding Systems is a valuable resource for researchers and professionals working in wireless communications and networks. Advanced-level students studying computer science and electrical engineering will also find the content helpful.
Coding Schemes for Physical Layer Network Coding Over a Two-Way Relay Channel
Author: Brett Michael HernPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
We consider a two-way relay channel in which two transmitters want to exchange information through a central relay. The relay observes a superposition of the trans- mitted signals from which a function of the transmitted messages is computed for broadcast. We consider the design of codebooks which permit the recovery of a function at the relay and derive information-theoretic bounds on the rates for reliable decoding at the relay. In the spirit of compute-and-forward, we present a multilevel coding scheme that permits reliable computation (or, decoding) of a class of functions at the relay. The function to be decoded is chosen at the relay depending on the channel realization. We define such a class of reliably computable functions for the proposed coding scheme and derive rates that are universally achievable over a set of channel gains when this class of functions is used at the relay. We develop our framework with general modulation formats in mind, but numerical results are presented for the case where each node transmits using 4-ary and 8-ary modulation schemes. Numerical results demonstrate that the flexibility afforded by our proposed scheme permits substantially higher rates than those achievable by always using a fixed function or considering only linear functions over higher order fields. Our numerical results indicate that it is favorable to allow the relay to attempt both compute-and-forward and decode-and-forward decoding. Indeed, either method considered separately is suboptimal for computation over general channels. However, we obtain a converse result when the transmitters are restricted to using identical binary linear codebooks generated uniformly at random. We show that it is impossible for this code ensemble to achieve any rate higher than the maximum of the rates achieved using compute-and-forward and decode-and-forward decoding. Finally, we turn our attention to the design of low density parity check (LDPC) ensembles which can practically achieve these information rates with joint-compute- and-forward message passing decoding. To this end, we construct a class of two-way erasure multiple access channels for which we can exactly characterize the performance of joint-compute-and-forward message passing decoding. We derive the processing rules and a density evolution like analysis for several classes of LDPC ensembles. Utilizing the universally optimal performance of spatially coupled LDPC ensembles with message passing decoding, we show that a single encoder and de- coder with puncturing can achieve the optimal rate region for a range of channel parameters. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/151149
Wireless Physical Layer Network Coding
Author: Jan SykoraPublisher: Cambridge University Press
ISBN: 1108652875
Category : Technology & Engineering
Languages : en
Pages : 338
Book Description
Discover a fresh approach for designing more efficient and cooperative wireless communications networks with this systematic guide. Covering everything from fundamental theory to current research topics, leading researchers describe a new, network-aware coding strategy that exploits the signal interactions that occur in dense wireless networks directly at the waveform level. Using an easy-to-follow, layered structure, this unique text begins with a gentle introduction for those new to the subject, before moving on to explain key information-theoretic principles and establish a consistent framework for wireless physical layer network coding (WPNC) strategies. It provides a detailed treatment of Network Coded Modulation, covers a range of WPNC techniques such as Noisy Network Coding, Compute and Forward, and Hierarchical Decode and Forward, and explains how WPNC can be applied to parametric fading channels, frequency selective channels, and complex stochastic networks. This is essential reading whether you are a researcher, graduate student, or professional engineer.
Wireless Physical Layer Network Coding
Author: Jan SykoraPublisher: Cambridge University Press
ISBN: 1108636977
Category : Technology & Engineering
Languages : en
Pages : 337
Book Description
Discover a fresh approach for designing more efficient and cooperative wireless communications networks with this systematic guide. Covering everything from fundamental theory to current research topics, leading researchers describe a new, network-aware coding strategy that exploits the signal interactions that occur in dense wireless networks directly at the waveform level. Using an easy-to-follow, layered structure, this unique text begins with a gentle introduction for those new to the subject, before moving on to explain key information-theoretic principles and establish a consistent framework for wireless physical layer network coding (WPNC) strategies. It provides a detailed treatment of Network Coded Modulation, covers a range of WPNC techniques such as Noisy Network Coding, Compute and Forward, and Hierarchical Decode and Forward, and explains how WPNC can be applied to parametric fading channels, frequency selective channels, and complex stochastic networks. This is essential reading whether you are a researcher, graduate student, or professional engineer.
An Algebraic Approach to Physical-layer Network Coding
Author: Chen FengPerformance Analysis of Relay Network Using Partial Compute-and-Forward Scheme and Physical-layer Network Coding
Author: Navyatha GavvalaPublisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages : 30
Book Description
In this thesis, the bit error rate (BER) performance of a relay network using both a partial compute-and-forward (PCF) strategy and a decode-and-forward (DF) strategy is studied. The system model considered is a relay network, which has multiple sources, multiple relay nodes, and one destination. First, in this thesis, BER performance of the relay network is analyzed using a decode-and-forward strategy. Second, another approach, called a partial compute-and-forward strategy, is proposed. The key idea here is to add dither, to the transmitted messages, then encode and forward the messages to the relay nodes like lattice codes. Once the relay nodes receive the linear combination of transmitted signals, they first remove the dithered signal and then map it to a linear combination of the transmitted message. This linear combination of the message is forwarded to the destination under a power constraint at the relay. Results show that the BER performance of the partial compute-and-forward strategy is better than the decode-and-forward strategy applied at the relay nodes. This thesis also analyzes the BER performance of a four-user physical-layer network coding (PNC), the implementation of which enhances the throughput and routing capabilities of a relay network.
Coding for Relay Networks with Parallel Gaussian Channels
Author: Yu-Chih HuangPublisher:
ISBN:
Category :
Languages : en
Pages : 192
Book Description
A wireless relay network consists of multiple source nodes, multiple destination nodes, and possibly many relay nodes in between to facilitate its transmission. It is clear that the performance of such networks highly depends on information forwarding strategies adopted at the relay nodes. This dissertation studies a particular information forwarding strategy called compute-and-forward. Compute-and-forward is a novel paradigm that tries to incorporate the idea of network coding within the physical layer and hence is often referred to as physical layer network coding. The main idea is to exploit the superposition nature of the wireless medium to directly compute or decode functions of transmitted signals at intermediate relays in a network. Thus, the coding performed at the physical layer serves the purpose of error correction as well as permits recovery of functions of transmitted signals. For the bidirectional relaying problem with Gaussian channels, it has been shown by Wilson et al. and Nam et al. that the compute-and-forward paradigm is asymptotically optimal and achieves the capacity region to within 1 bit; however, similar results beyond the memoryless case are still lacking. This is mainly because channels with memory would destroy the lattice structure that is most crucial for the compute-and-forward paradigm. Hence, how to extend compute-and-forward to such channels has been a challenging issue. This motivates this study of the extension of compute-and-forward to channels with memory, such as inter-symbol interference. The bidirectional relaying problem with parallel Gaussian channels is also studied, which is a relevant model for the Gaussian bidirectional channel with inter-symbol interference and that with multiple-input multiple-output channels. Motivated by the recent success of linear finite-field deterministic model, we first investigate the corresponding deterministic parallel bidirectional relay channel and fully characterize its capacity region. Two compute-and-forward schemes are then proposed for the Gaussian model and the capacity region is approximately characterized to within a constant gap. The design of coding schemes for the compute-and-forward paradigm with low decoding complexity is then considered. Based on the separation-based framework proposed previously by Tunali et al., this study proposes a family of constellations that are suitable for the compute-and-forward paradigm. Moreover, by using Chinese remainder theorem, it is shown that the proposed constellations are isomorphic to product fields and therefore can be put into a multilevel coding framework. This study then proposes multilevel coding for the proposed constellations and uses multistage decoding to further reduce decoding complexity. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/149620
Design of Network Coding Schemes in Wireless Networks
Author: Zihuai LinPublisher: CRC Press
ISBN: 1000597679
Category : Technology & Engineering
Languages : en
Pages : 211
Book Description
This book provides a consolidated view of the various network coding techniques to be implemented at the design of the wireless networks for improving its overall performance. It covers multiple sources communicating with multiple destinations via a common relay followed by network coded modulation schemes for multiple access relay channels. Performance of the distributed systems based on distributed convolutional codes with network coded modulation is covered including a two-way relay channel (TWRC). Two MIF protocols are proposed including derivation of signal-to-noise ratio (SNR) and development of threshold of the channel conditions of both. Features: Systematically investigates coding and modulation for wireless relay networks. Discusses how to apply lattice codes in implementing lossless communications and lossy source coding over a network. Focusses on theoretical approach for performance optimization. Includes various network coding strategies for different networks. Reviews relevant existing and ongoing research in optimization along with practical code design. This book aims at Researchers, Professionals and Graduate students in Networking, Communications, Information, Coding Theory, Theoretical Computer Science, Performance Analysis and Resource Optimization, Applied Discrete Mathematics, and Applied Probability.
Network Simulation and Evaluation
Author: Zhaoquan GuPublisher: Springer Nature
ISBN: 9819745195
Category :
Languages : en
Pages : 412
Book Description