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As new systems and applications are introduced for next-generation wireless systems, the propagation channels in which they operate need to be characterized. This paper discusses propagation channels for four types of next-generation systems: (i) distributed Multiple-Input Multiple-Output (MIMO) and Cooperative MultiPoint (CoMP), systems, which require the characterization of correlation between c
Service discovery is central in pervasive middleware systems, built on top of the communication substrate using the more fundamental mechanisms for device discovery. In mobile pervasive systems devices come and go, and switch network frequently, demanding support for device discovery across heterogeneous networks. We present the design of a device discovery mechanism for the PalCom middleware that
The Bidirectional Efficient Algorithm for Searching code Trees (BEAST), which is an algorithm to efficiently determine the free distance and spectral components of convolutional encoders, is implemented for the Cell Broadband Engine Architecture, efficiently utilizing the underlying hardware. Exhaustive and random searches are carried out, presenting new rate R=1/2 convolutional encoding matrices
Large open and closed source organizations like Google, Facebook and Mozilla are migrating their products towards rapid releases. While this allows faster time-to-market and user feedback, it also implies less time for testing and bug fixing. Since initial research results indeed show that rapid releases fix proportionally less reported bugs than traditional releases, this paper investigates the c
In this paper, we present a random puncturing analysis of low-density parity-check (LDPC) code ensembles. We derive a simple analytic expression for the iterative belief propagation (BP) decoding threshold of a randomly punctured LDPC code ensemble on the binary erasure channel (BEC) and show that, with respect to the BP threshold, the strength and suitability of an LDPC code ensemble for random p
[Context] Coordinating a software project across distances is challenging. Even without geographical and time zone distances, other distances within a project can cause communication gaps. For example, organisational and cognitive distances between product owners and development-near roles such as developers and testers can lead to differences in understanding and interpretation of the business re
Realistic Multiple-Input Multiple-Outout (MIMO) radio channel models are required in order to make fair system comparisons and to design proper signal processing algorithms using this technology. This technical report presents a full parameterization of the COST 2100 MIMO channel model for peer-to-peer communication in the 300 MHz band. Measurements were carried out in a semi-rural and suburban en
This paper investigates linear precoding over nonsingular linear channels with additive white Gaussian noise, with lattice-type inputs. The aim is to maximize the minimum distance of the received lattice points, where the precoder is subject to an energy constraint. It is shown that the optimal precoder only produces a finite number of different lattices, namely perfect lattices, at the receiver.
Building big data analytics applications (BDA) in the Cloud introduces inevitable challenges such as loss of control and uncertainty. To address the existing challenges, numerous efforts have been made on BDA application engineering to optimise quality of BDA applications in the Cloud, such as performance and reliability. However, there is still a lack of systematic view on engineering BDA applica
An iterative decoding threshold analysis for terminated regular LDPC convolutional (LDPCC) codes is presented. Using density evolution techniques, the convergence behavior of an iterative belief propagation decoder is analyzed for the binary erasure channel and the AWGN channel with binary inputs. It is shown that for a terminated LDPCC code ensemble, the thresholds are better than for correspondi
Massive MIMO, also known as very-large MIMO or large-scale antenna systems, is a new technique that potentially can offer large network capacities in multi-user scenarios. With a massive MIMO system, we consider the case where a base station equipped with a large number of antenna elements simultaneously serves multiple single-antenna users in the same time-frequency resource. So far, investigatio
Consider the communication system model y = HFx+n, where H and F are the channel and precoder matrices, x is a vector of data symbols drawn from some lattice-type constellation, such as M-QAM, n is an additive white Gaussian noise vector and y is the received vector. It is assumed that both the transmitter and the receiver have perfect knowledge of the channel matrix H and that the transmitted sig
Carrier frequency offset (CFO) synchronization is a crucial issue in the implementation of orthogonal frequency division multiplexing (OFDM) systems. Since current technology tends to implement different standards in the same wireless device, a common frequency synchronization structure is desirable. Knowledge of the physical frame and performance and cost system requirements are needed to choose
Vehicle-to-vehicle (V2V) communications have received increasingattention lately, but there is a lack of reported results regarding important quantities such as path loss. This paper presents parameterized path loss models for V2V communications based on extensive sets of measurement data collected mainly under line-of-sight conditions in four different propagation environments: highway, rural, ur
We present a new algorithm for solving the LPN problem. The algorithm has a similar form as some previous methods, but includes a new key step that makes use of approximations of random words to a nearest codeword in a linear code. It outperforms previous methods for many parameter choices. In particular, we can now solve instances suggested for 80-bit security in cryptographic schemes like HB var
Time-reversal (TR) signal processing has the potential to focus the transmitted signal at a desired receive (Rx) location in both space and time. At lower frequency bands, TR in conjunction with array antennas at transmit (Tx) or Rx has been shown to significantly improve its focusing performance relative to the case of single antennas at both link ends. This work for the first time investigates T
In dynamic flexgrid optical networks, the usage of capacity may not be optimal due to the permanent process of setting up and tearing down connections, which, if not controlled, leads to spectrum fragmentation and, as a result, to increase of connection blocking. On top of this, a restoration mechanism that is launched in reaction to a link failure (cable cut) restores the affected lightpaths. Eve
This paper presents a hardware architecture of pulse shaping filter used in multicarrier systems. The filter can be configured to be used for both transmitter and receiver with limited overhead. Generic implementation complexity analysis for a filter in a multicarrier system with N sub-carriers is presented, while the implemented architecture is for a system with 128 sub-carriers. The pulse shapin
