System design and validation of multi-band OFDM wireless communications with multiple antennas

[no abstract

Differentially-encoded di-symbol time-division multiuser impulse radio in UWB channel

Ph.DDOCTOR OF PHILOSOPH

Towards an enhanced noncoherent massive MU-MIMO system

PhD ThesisMany multiple-input multiple-output (MIMO) downlink transmission schemes assume channel state information (CSI) is available at the receiver/transmitter. In practice, knowledge of CSI is often obtained by using pilot symbols transmitted periodically. However, for some systems, due to high mobility and the cost of channel training and estimation, CSI acquisition is not always feasible. The problem becomes even more difficult when many antennas are used in the system and the channel is changing very rapidly before training is completed. Moreover, as the number of transmit/receive antennas grows large, the number of pilot symbols, system overheads, latency, and power consumption will grow proportionately and thereby the system becomes increasingly complex. As an alternative, a noncoherent system may be used wherein the transmitter/receiver does not need any knowledge of the CSI to perform precoding or detection. This thesis focuses on the design of a noncoherent downlink transmission system to jointly improve the performance and achieve a simple low complexity transmission scheme in three MIMO system scenarios: low rate differential spacetime block coding (STBC) in a downlink multiuser (MU-MIMO) system; high rate differential algebraic STBC in a downlink MU-MIMO system; and differential downlink transmission in a massive MU-MIMO system. Three novel design methods for each of these systems are proposed and analysed thoroughly. For the MIMO system with a low rate noncoherent scheme, a differential STBC MU-MIMO system with a downlink transmission scheme is considered. Specifically, downlink precoding combined with differential modulation (DM) is used to shift the complexity from the receivers to the transmitter. The block diagonalization (BD) precoding scheme is used to cancel co-channel interference (CCI) in addition to exploiting its advantage of enhancing diversity. Since the BD scheme requires channel knowledge at the transmitter, the downlink spreading technique along with DM is also proposed, which does not require channel knowledge neither at the transmitter nor at the receivers. The orthogonal spreading (OS) scheme is employed to have similar principle as code division multiple access (CDMA) multiplexing scheme in order to eliminate the interference between users. As a STBC scheme, the Alamouti code is used that can be encoded/decoded using DM thereby eliminating the need for channel knowledge at the receiver. The proposed schemes yield low complexity transceivers while providing good performance. For the MIMO system with a high rate noncoherent scheme, a differential STBC MU-MIMO system that operates at a high data rate is considered. In particular, a full-rate full-diversity downlink algebraic transmission scheme combined with a differential STBC systems is proposed. To achieve this, perfect algebraic space time codes and Cayley differential (CD) transforms are employed. Since CSI is not needed at the differential receiver, differential schemes are ideal for multiuser systems to shift the complexity from the receivers to the transmitter, thus simplifying user equipment. Furthermore, OS matrices are employed at the transmitter to separate the data streams of different users and enable simple single user decoding. In the OS scheme, the transmitter does not require any knowledge of the CSI to separate the data streams of multiple users; this results in a system which does not need CSI at either end. With this system, to limit the number of possible codewords, a sphere decoder (SD) is used to decode the signals at the receiving end. The proposed scheme yields low complexity transceivers while providing full-rate full-diversity system with good performance. Lastly, a differential downlink transmission scheme is proposed for a massive MIMO system without explicit channel estimation. In particular, a downlink precoding technique combined with a differential encoding scheme is used to simplify the overall system complexity. A novel precoder is designed which, with a large number of transmit antennas, can effectively precancel the multiple access interference (MAI) for each user, thus enhancing the system performance. Maximising the worst case signal-to-interference-plus-noise ratio (SINR) is adopted to optimise the precoder for the users in which full power space profile (PSP) knowledge is available to the base station (BS). Also, two suboptimal solutions based on the matched and the orthogonality approach of PSP are provided to separate the data streams of multiple users. The decision feedback differential detection (DFDD) technique is employed to further improve the performance. In summary, the proposed methods eliminate MAI, enhance system performance, and achieve a simple low complexity system. Moreover, transmission overheads are significantly reduced, the proposed methods avoid explicit channel estimation at both ends.King Fahad Security Collage at the Ministry of Interior - Saudi Arabia

Radar Technology

In this book “Radar Technology”, the chapters are divided into four main topic areas: Topic area 1: “Radar Systems” consists of chapters which treat whole radar systems, environment and target functional chain. Topic area 2: “Radar Applications” shows various applications of radar systems, including meteorological radars, ground penetrating radars and glaciology. Topic area 3: “Radar Functional Chain and Signal Processing” describes several aspects of the radar signal processing. From parameter extraction, target detection over tracking and classification technologies. Topic area 4: “Radar Subsystems and Components” consists of design technology of radar subsystem components like antenna design or waveform design

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

Optimisation of Mobile Communication Networks - OMCO NET

The mini conference “Optimisation of Mobile Communication Networks” focuses on advanced methods for search and optimisation applied to wireless communication networks. It is sponsored by Research & Enterprise Fund Southampton Solent University. The conference strives to widen knowledge on advanced search methods capable of optimisation of wireless communications networks. The aim is to provide a forum for exchange of recent knowledge, new ideas and trends in this progressive and challenging area. The conference will popularise new successful approaches on resolving hard tasks such as minimisation of transmit power, cooperative and optimal routing

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