Ultra-Wideband Relay Communication Systems

Impulse-radio ultra-wide-band (IR-UWB) signaling is a promising technique for high-speed, short-range relay communications networks. Depending on how the relay node retransmits the signal, there are two main relay schemes: conventional one-directional (one-way) relay model, and bi-directional (two-way) relay model. In bi-directional relay communications, wireless network coding (WNC), also called physical-layer network coding (PNC), could be applied to overcome the spectral efficiency limitation of the conventional one-way relay. In the first part of this work, we propose asynchronous, differential, and bidirectional decode and forward (ADBDF) and asynchronous, differential, and bidirectional denoise and forward (ADBDNF) UWB relay methods, where the relay node (RN) does not need to be synchronized with the end nodes (ENs). The proposed schemes are attractive for networks in which stringent/complicated synchronization between the RN and the ENs may not be feasible. The second part of this work focuses on UWB channel classification. We propose a 2-dimensional (2-D) LOS/NLOS classification scheme that uses skewness of the channel impulse/pulse response. The proposed channel classification decreases the complexity of existing channel classification methods and can be used in a variety of areas such as localization, relay communications, and cooperative communications. The final part of this work deals with compressive sensing (CS) algorithms that employ sub-Nyquist sampling for UWB communications. We develop coarse graining (CG) for the proposed CS sub-Nyquist sampling technique, which leads to: (1) reduced sampling rate at the receiver, and hence reduced use of analog-to-digital converters (ADCs) resources; and (2) low-complexity channel estimation

Ultra Wideband

Ultra wideband (UWB) has advanced and merged as a technology, and many more people are aware of the potential for this exciting technology. The current UWB field is changing rapidly with new techniques and ideas where several issues are involved in developing the systems. Among UWB system design, the UWB RF transceiver and UWB antenna are the key components. Recently, a considerable amount of researches has been devoted to the development of the UWB RF transceiver and antenna for its enabling high data transmission rates and low power consumption. Our book attempts to present current and emerging trends in-research and development of UWB systems as well as future expectations

Self-concatenated coding for wireless communication systems

In this thesis, we have explored self-concatenated coding schemes that are designed for transmission over Additive White Gaussian Noise (AWGN) and uncorrelated Rayleigh fading channels. We designed both the symbol-based Self-ConcatenatedCodes considered using Trellis Coded Modulation (SECTCM) and bit-based Self- Concatenated Convolutional Codes (SECCC) using a Recursive Systematic Convolutional (RSC) encoder as constituent codes, respectively. The design of these codes was carried out with the aid of Extrinsic Information Transfer (EXIT) charts. The EXIT chart based design has been found an efficient tool in finding the decoding convergence threshold of the constituent codes. Additionally, in order to recover the information loss imposed by employing binary rather than non-binary schemes, a soft decision demapper was introduced in order to exchange extrinsic information withthe SECCC decoder. To analyse this information exchange 3D-EXIT chart analysis was invoked for visualizing the extrinsic information exchange between the proposed Iteratively Decoding aided SECCC and soft-decision demapper (SECCC-ID). Some of the proposed SECTCM, SECCC and SECCC-ID schemes perform within about 1 dB from the AWGN and Rayleigh fading channels’ capacity. A union bound analysis of SECCC codes was carried out to find the corresponding Bit Error Ratio (BER) floors. The union bound of SECCCs was derived for communications over both AWGN and uncorrelated Rayleigh fading channels, based on a novel interleaver concept.Application of SECCCs in both UltraWideBand (UWB) and state-of-the-art video-telephone schemes demonstrated its practical benefits.In order to further exploit the benefits of the low complexity design offered by SECCCs we explored their application in a distributed coding scheme designed for cooperative communications, where iterative detection is employed by exchanging extrinsic information between the decoders of SECCC and RSC at the destination. In the first transmission period of cooperation, the relay receives the potentially erroneous data and attempts to recover the information. The recovered information is then re-encoded at the relay using an RSC encoder. In the second transmission period this information is then retransmitted to the destination. The resultant symbols transmitted from the source and relay nodes can be viewed as the coded symbols of a three-component parallel-concatenated encoder. At the destination a Distributed Binary Self-Concatenated Coding scheme using Iterative Decoding (DSECCC-ID) was employed, where the two decoders (SECCC and RSC) exchange their extrinsic information. It was shown that the DSECCC-ID is a low-complexity scheme, yet capable of approaching the Discrete-input Continuous-output Memoryless Channels’s (DCMC) capacity.Finally, we considered coding schemes designed for two nodes communicating with each other with the aid of a relay node, where the relay receives information from the two nodes in the first transmission period. At the relay node we combine a powerful Superposition Coding (SPC) scheme with SECCC. It is assumed that decoding errors may be encountered at the relay node. The relay node then broadcasts this information in the second transmission period after re-encoding it, again, using a SECCC encoder. At the destination, the amalgamated block of Successive Interference Cancellation (SIC) scheme combined with SECCC then detects and decodes the signal either with or without the aid of a priori information. Our simulation results demonstrate that the proposed scheme is capable of reliably operating at a low BER for transmission over both AWGN and uncorrelated Rayleigh fading channels. We compare the proposed scheme’s performance to a direct transmission link between the two sources having the same throughput

Cooperative communications in wireless networks : novel approaches in the mac layer

Master'sMASTER OF ENGINEERIN

Multiuser Two-Way Filter-and-Forward Relaying for Ultra-Wideband Communications

Abstract-In this paper, a multiuser two-way filter-and-forward relaying scheme for wireless communication over wideband channels is considered. We propose pre/post-rake processing in conjunction with optimized filtering at the relay to reduce the signal processing burden at the source and destination nodes. Two relay filter design problem formulations are introduced, namely (a) a convex optimization problem formulation with closed-form solutions and (b) the more general case, which is a non-convex problem solvable via an alternating optimization algorithm. For both design alternatives widely linear formulations are devised. The presented numerical results demonstrate the capability of the proposed designs to establish reliable two-way communication links between nodes with limited signal processing power and in the absence of a direct link

Cooperative routing in wireless ad hoc networks.

Cheung, Man Hon.Thesis (M.Phil.)--Chinese University of Hong Kong, 2007.Includes bibliographical references (leaves 89-94).Abstracts in English and Chinese.Abstract --- p.iAcknowledgement --- p.iiiChapter 1 --- Introduction --- p.1Chapter 1.1 --- Rayleigh Fading Channels --- p.1Chapter 1.2 --- Ultra-Wideband (UWB) Communications --- p.2Chapter 1.2.1 --- Definition --- p.2Chapter 1.2.2 --- Characteristics --- p.3Chapter 1.2.3 --- UWB Signals --- p.4Chapter 1.2.4 --- Applications --- p.5Chapter 1.3 --- Cooperative Communications --- p.7Chapter 1.4 --- Outline of Thesis --- p.7Chapter 2 --- Background Study --- p.9Chapter 2.1 --- Interference-Aware Routing --- p.9Chapter 2.2 --- Routing in UWB Wireless Networks --- p.11Chapter 2.3 --- Cooperative Communications and Routing --- p.12Chapter 3 --- Cooperative Routing in Rayleigh Fading Channel --- p.15Chapter 3.1 --- System Model --- p.16Chapter 3.1.1 --- Transmitted Signal --- p.16Chapter 3.1.2 --- Received Signal and Maximal-Ratio Combining (MRC) --- p.16Chapter 3.1.3 --- Probability of Outage --- p.18Chapter 3.2 --- Cooperation Criteria and Power Distribution --- p.21Chapter 3.2.1 --- Optimal Power Distribution Ratio --- p.21Chapter 3.2.2 --- Near-Optimal Power Distribution Ratio β´ة --- p.21Chapter 3.2.3 --- Cooperation or Not? --- p.23Chapter 3.3 --- Performance Analysis and Evaluation --- p.26Chapter 3.3.1 --- 1D Poisson Random Network --- p.26Chapter 3.3.2 --- 2D Grid Network --- p.28Chapter 3.4 --- Cooperative Routing Algorithm --- p.32Chapter 3.4.1 --- Cooperative Routing Algorithm --- p.33Chapter 3.4.2 --- 2D Random Network --- p.35Chapter 4 --- UWB System Model and BER Expression --- p.37Chapter 4.1 --- Transmit Signal --- p.37Chapter 4.2 --- Channel Model --- p.39Chapter 4.3 --- Received Signal --- p.39Chapter 4.4 --- Rake Receiver with Maximal-Ratio Combining (MRC) --- p.41Chapter 4.5 --- BER in the presence of AWGN & MUI --- p.46Chapter 4.6 --- Rake Receivers --- p.47Chapter 4.7 --- Comparison of Simple Routing Algorithms in ID Network --- p.49Chapter 5 --- Interference-Aware Routing in UWB Wireless Networks --- p.57Chapter 5.1 --- Problem Formulation --- p.57Chapter 5.2 --- Optimal Interference-Aware Routing --- p.58Chapter 5.2.1 --- Link Cost --- p.58Chapter 5.2.2 --- Per-Hop BER Requirement and Scaling Effect --- p.59Chapter 5.2.3 --- Optimal Interference-Aware Routing --- p.61Chapter 5.3 --- Performance Evaluation --- p.64Chapter 6 --- Cooperative Routing in UWB Wireless Networks --- p.69Chapter 6.1 --- Two-Node Cooperative Communication --- p.69Chapter 6.1.1 --- Received Signal for Non-Cooperative Communication --- p.69Chapter 6.1.2 --- Received Signal for Two-Node Cooperative Communication --- p.70Chapter 6.1.3 --- Probability of Error --- p.71Chapter 6.2 --- Problem Formulation --- p.75Chapter 6.3 --- Cooperative Routing Algorithm --- p.77Chapter 6.4 --- Performance Evaluation --- p.80Chapter 7 --- Conclusion and Future Work --- p.85Chapter 7.1 --- Conclusion --- p.85Chapter 7.2 --- Future Work --- p.86Chapter 7.2.1 --- Distributed Algorithm --- p.87Chapter 7.2.2 --- Performance Analysis in Random Networks --- p.87Chapter 7.2.3 --- Cross-Layer Optimization --- p.87Chapter 7.2.4 --- Game Theory --- p.87Chapter 7.2.5 --- Other Variations in Cooperative Schemes --- p.88Bibliography --- p.8

Timing and Carrier Synchronization in Wireless Communication Systems: A Survey and Classification of Research in the Last 5 Years

Timing and carrier synchronization is a fundamental requirement for any wireless communication system to work properly. Timing synchronization is the process by which a receiver node determines the correct instants of time at which to sample the incoming signal. Carrier synchronization is the process by which a receiver adapts the frequency and phase of its local carrier oscillator with those of the received signal. In this paper, we survey the literature over the last 5 years (2010–2014) and present a comprehensive literature review and classification of the recent research progress in achieving timing and carrier synchronization in single-input single-output (SISO), multiple-input multiple-output (MIMO), cooperative relaying, and multiuser/multicell interference networks. Considering both single-carrier and multi-carrier communication systems, we survey and categorize the timing and carrier synchronization techniques proposed for the different communication systems focusing on the system model assumptions for synchronization, the synchronization challenges, and the state-of-the-art synchronization solutions and their limitations. Finally, we envision some future research directions

Cooperative Radio Communications for Green Smart Environments

The demand for mobile connectivity is continuously increasing, and by 2020 Mobile and Wireless Communications will serve not only very dense populations of mobile phones and nomadic computers, but also the expected multiplicity of devices and sensors located in machines, vehicles, health systems and city infrastructures. Future Mobile Networks are then faced with many new scenarios and use cases, which will load the networks with different data traffic patterns, in new or shared spectrum bands, creating new specific requirements. This book addresses both the techniques to model, analyse and optimise the radio links and transmission systems in such scenarios, together with the most advanced radio access, resource management and mobile networking technologies. This text summarises the work performed by more than 500 researchers from more than 120 institutions in Europe, America and Asia, from both academia and industries, within the framework of the COST IC1004 Action on "Cooperative Radio Communications for Green and Smart Environments". The book will have appeal to graduates and researchers in the Radio Communications area, and also to engineers working in the Wireless industry. Topics discussed in this book include: • Radio waves propagation phenomena in diverse urban, indoor, vehicular and body environments• Measurements, characterization, and modelling of radio channels beyond 4G networks• Key issues in Vehicle (V2X) communication• Wireless Body Area Networks, including specific Radio Channel Models for WBANs• Energy efficiency and resource management enhancements in Radio Access Networks• Definitions and models for the virtualised and cloud RAN architectures• Advances on feasible indoor localization and tracking techniques• Recent findings and innovations in antenna systems for communications• Physical Layer Network Coding for next generation wireless systems• Methods and techniques for MIMO Over the Air (OTA) testin