Filetype
This paper presents a heterogeneous reconfigurable cell array, designed for high-throughput baseband processing of multiple-input multiple-output (MIMO) systems. To achieve high performance and energy efficiency while retaining high flexibility, the proposed architecture adopts heterogeneous and hierarchical resource deployments. Additionally, extensive vector computation enhancements and flexible
This paper presents an area/energy efficient soft-output MIMO detector that supports the detection of spatial-multiplexing (SM), spatial-diversity (SD), and space-division-multiple-access (SDMA)signals. The developed near-optimal detection algorithms for these tree modes share most of the mathematical operations to enable extensive hardware reuse. A unified VLSI architecture is accordingly designe
In this paper we present an improved algorithm for finding low-weight multiples of polynomials over the binary field using coding theoretic methods. The associated code defined by the given polynomial has a cyclic structure, allowing an algorithm to search for shifts of the sought minimum-weight codeword. Therefore, a code with higher dimension is constructed, having a larger number of low-w
Network re-optimization is a process that must be triggered periodically in order to improve the inefficient resource allocation of online routing heuristics due to the uncertainty of online lightpath demand arrivals and departures. Network re-optimization involves two tasks: a) finding new lightpaths for a (sub)set of current demands, i.e. rerouting, and b) migrating the current traffic to the ne
We use a 2-dimensional (2-D) Vernier gated-ring-oscillator (GRO) time-to-digital-converter (TDC) in a cascade structure (MASH), so that a larger raw quantization step can be allowed without sacrificing the final resolution performance. The 2-D approach effectively reduces the latency time under a large input, while the MASH structure provides a 2nd-order noise shaping that produces a lower in-band
Abstract in Undetermined Given an undirected graph g(V, E), a set of traffic matrices H and one additional traffic matrix h, we say that H totally dominates h if, for each capacity reservation u supporting H, u also supports h using the same routing pattern. It has been shown that if vertical bar H vertical bar = 1 = (H = {(h) over cap}, say) and g, is a complete graph, H totally dominates h if, a
There is currently a high demand for spatial data usage within web applications. From a technical viewpoint, web services and geoportals aim to fulfil user requirements; however, the current cartographic methods do not satisfy the needs of the end users. The problem is more challenging when the final map contains data from various sources that have various cartographic characteristics; therefore,
This paper presents a Sorted QR-Decomposition (SQRD) processor for 3GPP LTE-A system. It achieves energy efficiency by co-optimizing techniques, such as heterogeneous processing, reconfigurable architecture, and dual-supply voltage operation. At algorithm level, a low-complexity hybrid decomposition scheme is adopted, which switches, depending on the energy distribution of spatial channels, betwee
In Space Division Multiple Access (SDMA) systems, users are separated based on their positions. The base-station (BS) signals typically reach the users through multipath clusters. The goal of this work is to find the probability that a randomly selected user will receive the signal from the BS via at least one nonshared (by any other user) multipath cluster. This probability, referred to as PSucce
Open source components can be used as one type of software component in development of commercial software. In development using this type of component, potential open source components must first be identified, then specific components must be selected, and after that selected components should maybe be adapted before they are included in the developed product. A company using open source compone
Reference attribute grammars (RAGs) provide a practical declarative means to implement programming language compilers and other tools. RAGs have previously been extended to support nonterminal attributes (also known as higher-order attributes), circular attributes, and context-dependent declarative rewrites of the abstract syntax tree. In this previous work, interdependencies between these extensi
Real-time applications introduce new requirements on wireless networks and impose quality thresholds on parameters like delay, jitter, throughput, and packet loss in order to run smoothly. This paper addresses this issue by presenting a MAC scheme that offers real-time applications the opportunity to reserve transmission time based on their QoS requirements for contention-free medium access. Our s
Bug report assignment is an important part of software maintenance. In particular, incorrect assignments of bug reports to development teams can be very expensive in large software development projects. Several studies propose automating bug assignment techniques using machine learning in open source software contexts, but no study exists for large-scale proprietary projects in industry. The goal
This paper presents the design of a digital PLL which uses a high resolution Gated-Ring-Oscillator-Based Vernier Time-to-Digital Converter (TDC) for low noise RF application. The TDC uses two gated ring oscillators (GRO) acting as the delay lines in an improved Vernier TDC. The already small quantization noise of the standard Vernier TDC is further first-order shaped by the GRO operation. Addition
Optimization models related to designing and operating complex systems are mainly focused on some efficiency metrics such as response time, queue length, throughput, and cost. However, in systems which serve many entities there is also a need for respecting fairness: each system entity ought to be provided with an adequate share of the system's services. Still, due to system operations-dependant c
Conventional antennas in single-antenna terminals that resonate at frequencies lower than 1 GHz usually rely on the chassis as the main radiator. To effectively exploit chassis excitation for MIMO terminals, each of the multiple antennas is required to excite one distinct chassis mode. However, in today's terminals, there is typically only one chassis mode that can radiate efficiently at frequenci
Modern large-scale software development is a complex undertaking and coordinating various processes is crucial to achieve efficiency. The alignment between requirements and test activities is one important aspect. Production and maintenance of software result in an ever-increasing amount of information. To be able to work efficiently under such circumstances, navigation in all available data needs
Requirements Engineering has recently been greatly influenced by the way how firms use Open Source Software (OSS) and Software Ecosystems (SECOs) as a part of their product development and business models. This is further emphasized by the paradigm of Open Innovation, which highlights how firms should strive to use both internal and external resources to advance their internal innovation and techn
This paper presents preliminary results for a novel 128-antenna massive Multiple-Input, Multiple-Output (MIMO) testbed developed through Bristol Is Open in collaboration with National Instruments and Lund University. We believe that the results presented here validate the adoption of massive MIMO as a key enabling technology for 5G and pave the way for further pragmatic research by the massive MIM
