18 research outputs found

    Structured Parallel Architecture for Displacement MIMO Kalman Equalizer in CDMA Systems

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    A reduced complexity MIMO Kalman equalizer architecture is proposed in this brief by jointly considering the displacement structure and the block-Toeplitz structure. Numerical matrix–matrix multiplications with O(F3) complexity are eliminated by simple data loading process, where is the spreading factor. Finally, an iterative Conjugate-Gradient based algorithm is proposed to avoid the inverse of the Hermitian symmetric innovation covariance matrix in Kalman gain processor. The proposed architecture not only reduces the numerical complexity from O(F2) to O(Flog2F) per chip, but also facilitates the parallel and pipelined VLSI implementation in real-time processing

    Receiver algorithms that enable multi-mode baseband terminals

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    Performance study of air interface for broadband wireless packet access

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    Ph.DDOCTOR OF PHILOSOPH

    Survey of FPGA applications in the period 2000 – 2015 (Technical Report)

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    Romoth J, Porrmann M, Rückert U. Survey of FPGA applications in the period 2000 – 2015 (Technical Report).; 2017.Since their introduction, FPGAs can be seen in more and more different fields of applications. The key advantage is the combination of software-like flexibility with the performance otherwise common to hardware. Nevertheless, every application field introduces special requirements to the used computational architecture. This paper provides an overview of the different topics FPGAs have been used for in the last 15 years of research and why they have been chosen over other processing units like e.g. CPUs

    Exploration of the scalability of SIMD processing for software defined radio

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    The idea of software defined radio (SDR) describes a signal processing system for wireless communications that allows performing major parts of the physical layer processing in software. SDR systems are more flexible and have lower development costs than traditional systems based on application-specific integrated circuits (ASICs). Yet, SDR requires programmable processor architectures that can meet the throughput and energy efficiency requirements of current third generation (3G) and future fourth generation (4G) wireless standards for mobile devices. Single instruction, multiple data (SIMD) processors operate on long data vectors in parallel data lanes and can achieve a good ratio of computing power to energy consumption. Hence, SIMD processors could be the basis of future SDR systems. Yet, SIMD processors only achieve a high efficiency if all parallel data lanes can be utilized. This thesis investigates the scalability of SIMD processing for algorithms required in 4G wireless systems; i. e. the scaling of performance and energy consumption with increasing SIMD vector lengths is explored. The basis of the exploration is a scalable SIMD processor architecture, which also supports long instruction word (LIW) execution and can be configured with four different permutation networks for vector element permutations. Radix-2 and mixed-radix fast Fourier transform (FFT) algorithms, sphere decoding for multiple input, multiple output (MIMO) systems, and the decoding of quasi-cyclic lowdensity parity check (LDPC) codes have been examined, as these are key algorithms for 4G wireless systems. The results show that the performance of all algorithms scales with the SIMD vector length, yet there are different constraints on the ratios between algorithm and architecture parameters. The radix-2 FFT algorithm allows close to linear speedups if the FFT size is at least twice the SIMD vector length, the mixed-radix FFT algorithm requires the FFT size to be a multiple of the squared SIMD width. The performance of the implemented sphere decoding algorithm scales linearly with the SIMD vector length. The scalability of LDPC decoding is determined by the expansion factor of the quasicyclic code. Wider SIMD processors offer better performance and also require less energy than processors with a shorter vector length for all considered algorithms. The results for different permutations networks show that a simple permutation network is sufficient for most applications

    Analog Radio-over-Fiber for 5G/6G Millimeter-Wave Communications

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    MIMO Systems

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    In recent years, it was realized that the MIMO communication systems seems to be inevitable in accelerated evolution of high data rates applications due to their potential to dramatically increase the spectral efficiency and simultaneously sending individual information to the corresponding users in wireless systems. This book, intends to provide highlights of the current research topics in the field of MIMO system, to offer a snapshot of the recent advances and major issues faced today by the researchers in the MIMO related areas. The book is written by specialists working in universities and research centers all over the world to cover the fundamental principles and main advanced topics on high data rates wireless communications systems over MIMO channels. Moreover, the book has the advantage of providing a collection of applications that are completely independent and self-contained; thus, the interested reader can choose any chapter and skip to another without losing continuity

    Optics for AI and AI for Optics

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    Artificial intelligence is deeply involved in our daily lives via reinforcing the digital transformation of modern economies and infrastructure. It relies on powerful computing clusters, which face bottlenecks of power consumption for both data transmission and intensive computing. Meanwhile, optics (especially optical communications, which underpin today’s telecommunications) is penetrating short-reach connections down to the chip level, thus meeting with AI technology and creating numerous opportunities. This book is about the marriage of optics and AI and how each part can benefit from the other. Optics facilitates on-chip neural networks based on fast optical computing and energy-efficient interconnects and communications. On the other hand, AI enables efficient tools to address the challenges of today’s optical communication networks, which behave in an increasingly complex manner. The book collects contributions from pioneering researchers from both academy and industry to discuss the challenges and solutions in each of the respective fields

    Cooperative Radio Communications for Green Smart Environments

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    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
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