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We find good rate 2/3 and 3/4 convolutional codes for use with iterative decoding (turbo equalization) of coded intersymbol interference with AWGN. The method is based on the input-output bit error rate characteristic of the convolutional BCJR decoder module. An analysis leads to an equivalent minimum distance under the required intrinsic subtraction, which depends on free distance and an input-ou
Creation and adoption of corporate policies requires significant commitment of scarce senior management resources. In the absence of processes and tools, convergence upon final policy and may not be achieved in a timely manner. Significant similarities between policy and requirements documents suggest that requirements engineering techniques could be used to generate policy. However, neither evide
In this paper, we give an overview of spatially coupled turbo codes (SC-TCs), the spatial coupling of parallel and serially concatenated convolutional codes, recently introduced by the authors. For presentation purposes, we focus on spatially coupled serially concatenated codes (SC-SCCs). We review the main principles of SC-TCs and discuss their exact density evolution (DE) analysis on the binary
Multipath routing gives traffic demands an opportunity to use multiple paths through a network. In a single-demand situation, its benefits are easy to see. In a multi-commodity case, when potentially all node-pairs (demands) generate traffic, they compete for the same network resources. In this work, we consider multipath routing in communication networks in a multi-commodity setting from a traffi
Analog decoders are constructed based on interconnecting CMOS Gilbert vector multipliers using transistors operating in the sub-VT region. They are seen as an interesting alternative to digital implementations with a low transistor count and a potential for a very low power consumption. Analog implementation makes the circuit sensitive to mismatch, requiring careful transistor sizing. A simulation
In this paper we prove threshold saturation for spatially coupled turbo codes (SC-TCs) and braided convolutional codes (BCCs) over the binary erasure channel. We introduce a compact graph representation for the ensembles of SC-TC and BCC codes which simplifies their description and the analysis of the message passing decoding. We demonstrate that by few assumptions in the ensembles of these codes,
Signal-to-noise ratio (SNR) estimation is commonly used in wireless receivers to enhance the performance in different ways. In this paper a novel low complexity SNR estimator for OFDM is proposed. The estimator might be implemented using floating point representation or by using only the sign-bit, and can if desired be effectively implemented by reconfiguring the standard correlator used for time-
In the emerging Delay Tolerant Networks (DTNs) content dissemination platform, mobile nodes opportunistically exchange content as they meet, with the intent of sharing content among nodes with common interests. During a meeting, nodes can exchange both content of direct interest to themselves as well as content that is of interest to a larger set of nodes that may be encountered in the future. The
Reference attribute grammars (RAGs) can be used to express semantics as super-imposed graphs on top of abstract syntax trees (ASTs). A RAG-based AST can be used as the in-memory model providing semantic information for software language tools such as compilers, refactoring tools, and meta- modeling tools. RAG performance is based on dynamic attribute evaluation with caching. Caching all attributes
Many large companies, from the traditionally proprietary software industry, are opening up and embracing the open source software (OSS) development process model as a part of their business strategy. Despite the recognized potential the OSS community offers, there are still many questions and unknowns about the transition process. We present an extensive analysis of static software quality metric
Numerous geometric problems in computer vision in- volve the solution of systems of polynomial equations. This is true for problems with minimal information, but also for finding stationary points for overdetermined problems. The state-of-the-art is based on the use of numerical linear algebra on the large but sparse co- efficient matrix that represents the expanded original equation set. In this
This paper presents a fully integrated downlink for low-cost remote antenna units in fiber-fed distributed multi-antenna systems. To reduce the cost of optical parts, an intermediate frequency(IF) signal is distributed over the fiber, and the circuit consists of an optical receiver, a single side-band frequency up-converting radio transmitter, and LO generation circuitry. The optical to electrical
An Orthogonal Frequency-Division Multiplexing (OFDM) based multi-user massive Multiple-Input Multiple-Output (MIMO) system is considered. The problem of high Peak-to-Average Ratio (PAR) in OFDM based systems is well known and the large number of antennas (RF-chains) at the Base Station (BS) in massive MIMO systems aggravates this further, since large numbers of these Power Amplifiers (PAs) are use
[Context and motivation] This research preview presents ongoing work on a free software requirements modeling tool called reqT that is developed in an educational context. [Question/problem] The work aims to engage computer science students in Requirements Engineering (RE) through a tool that captures essential RE concepts in executable code. [Principal ideas] Requirements are modeled using an int
Many cryptographic primitives rely on word rotations (R) and xor (X) to provide proper mixing. We give RX-system mixing a very general treatment and deduce some theoretical results on related probability distributions. Pure RX-systems are easy to break, so we show how to apply our theory to a more complex system that uses RX operations in combination with S-boxes. We construct an impractical (key
This book focuses on domain-specific heterogeneous reconfigurable architectures, demonstrating for readers a computing platform which is flexible enough to support multiple standards, multiple modes, and multiple algorithms. The content is multi-disciplinary, covering areas of wireless communication, computing architecture, and circuit design. The platform described provides real-time processing c
Clustering is a key concept of existing MIMO channel models, such as the COST 2100 model. Parameter based clustering has been studied for a while, but how parameter based clusters relate to the physical environment is not well known yet. A measurement based ray launching tool is developed and used for studying clustering and its relation to physical scatterers. By using estimated angles and delays
