Integration of TETRA with Satellite Networks: A Contribution to the IMT-A Vision

The paper addresses the integration architecture (I-concept) between a terrestrial technology—TETRA (TErrestrial Trunked Radio)—and satellite systems. This approach, that enhances and harmonises the features of both technologies, could provide an interesting contribution to the effectiveness of the International Mobile Telecommunications-Advanced (IMT-A) and, hence, to the 4G vision. TETRA can represent an interesting building block of an integrated network devoted to both civil and military scenarios; it meets the “suitable technological capability” requirement for integration, because it represents a consolidated terrestrial technology that can be trusted, hence focusing the integration effort on the definition, design and implementation of proper interfaces. System architectures are here proposed referring to short, medium term and long term scenarios.

Isolation of Failing Scan Cells through Convolutional Test Response Compaction

This paper describes a non-recursive fault diagnosis technique for scan-based designs with convolutional test response compaction. The proposed approach allows a time-efficient and accurate identification of failing scan cells using Gauss–Jordan elimination method.

Negative Save Sign Extension for Multi-term Adders and Multipliers

This paper outlines a new sign extension technique for use in carry save adder trees that reduces the computational complexity. The “Negative Save” technique presented is a modification to the Baugh–Wooley sign extension technique developed for array multipliers. Applying this sign extension technique to both parallel adder and multiplier partial product structures reduces the hardware required. The speed of the resulting structures is also improved.

Ad hoc networks beyond unit disk graphs

In this paper, we study an algorithmic model for wireless ad hoc and sensor networks that aims to be sufficiently close to reality as to represent practical realworld networks while at the same time being concise enough to promote strong theoretical results. The quasi unit disk graph model contains all edges shorter than a parameter d between 0 and 1 and no edges longer than 1. We show that—in comparison to the cost known for unit disk graphs—the complexity results of geographic routing in this model contain the additional factor 1/d ². We prove that in quasi unit disk graphs flooding is an asymptotically message-optimal routing technique, we provide a geographic routing algorithm being most efficient in dense networks, and we show that classic geographic routing is possible with the same asymptotic performance guarantees as for unit disk graphs if .

Layereless Communications: From Dream to Reality?

The paper summarizes the main results of one of the key panel session of the Workshop, focused on the investigation about the possible translation of the “layerless communications” from a dreaming vision to reality.

Energy-Aware Georouting with Guaranteed Delivery in Wireless Sensor Networks with Obstacles

We propose, end-to-end (EtE), a novel EtE localized routing protocol for wireless sensor networks that is energy-efficient and guarantees delivery. To forward a packet, a node s in graph G computes the cost of the energy weighted shortest path (SP) between s and each of its neighbors in the forward direction towards the destination which minimizes the ratio of the cost of the SP to the progress (reduction in distance towards the destination). It then sends the message to the first node on the SP from s to x: say node x′. Node x′ restarts the same greedy routing process until the destination is reached or an obstacle is encountered and the routing fails. To recover from the latter scenario, local minima trap, our algorithm invokes an energy-aware Face routing that guarantees delivery. Our work is the first to optimize energy consumption of Face routing. It works as follows. First, it builds a connected dominating set from graph G, second it computes its Gabriel graph to obtain the planar graph G′. Face routing is invoked and applied to G′ only to determine which edges to follow in the recovery process. On each edge, greedy routing is applied. This two-phase (greedy–Face) EtE routing process reiterates until the final destination is reached. Simulation results show that EtE outperforms several existing geographical routing on energy consumption metric and delivery rate. Moreover, we prove that the computed path length and the total energy of the path are constant factors of the optimal for dense networks.

---

Performances of the H-ARQ Adaptive-QAM Transmissions over Multipath Channels

This paper presents the evaluation of the average spectral efficiencies provided by the adaptive use of a set of LDPC-coded QAM modulations in an OFDMA downlink scheme over mobile radio channels, considering a joint modeling of the channel and user-access method. It discusses the selection of the set of coded modulations, briefly describes the joint modeling of the channel and access method employed, and derives the average spectral efficiency provided by this approach in non-ARQ or H-ARQ environments. Some comments about the effects of the system’s parameters upon its performances are also included.

A Fast-Deblocking Boundary-strength Based Architecture Design of Deblocking Filter in H.264/AVC Applications

This work presents an efficient architecture design for deblocking filter in H.264/AVC using a novel fast-deblocking boundary-strength (FDBS) technique. Based on the FDBS technique, the proposed architecture divides the deblocking process into three filtering modes, namely offset-based, standard-based and diagonal-based filtering modes, to reduce the blocking artifact and improve the video quality in H.264/AVC. The proposed architecture is designed in Verilog HDL, simulated with Quartus II and synthesized using 0.18 μm CMOS cells library with the Synopsys Design Compiler. Simulation results demonstrate good performance in PSNR improvement and bit-rate reduction. Additionally, verification results through physical chip design reveal that the proposed architecture design can support 1,280 × 720@30 Hz processing throughput while clocking at 100 MHz. Comparisons with other studies show the excellent properties of the proposed architecture in terms of gate count, memory size and clock-cycle/macroblock.

A Novel Adaptive Detection Scheme based on Parallel Interference Cancellation for V-BLAST System

In this paper, in order to reduce the computational complexity of the detector of vertical Bell Laboratories layered space-time (V-BLAST) system over time-varying channels, an adaptive detection scheme is proposed based on parallel interference cancellation (PIC). The presented scheme has three units, which are primary adaptive detector, detection ordering determiner, and adaptive PIC detector. The proposed scheme can employ many of known adaptive algorithms for detection of V-BLAST system. In this paper, we present computational complexity of the proposed scheme using LMS, RLS, APA and AMSER adaptive algorithms and evaluate its performance with numerical simulations.

A Context Driven Architecture for Cognitive Radio Nodes

A cognitive radio (CR), in its generic form, needs to be highly flexible and adaptive while desirably hiding its complexities from users and system programmers. For the autonomic management the CR needs to be aware of the ‘self’ and the ‘world’ around it. Embedded intelligence with cognitive and collaborative adaptations require innovative techniques for managing the functionality of the device. Complexity of the cognitive processes involved demand for formal methods for run time evaluations and verification. In this paper we propose a generic architecture for a cognitive node with a context driven approach which incorporates some formalisms including context spaces, ontology, process algebra to represent and manipulate various cognitive processes managing the cognitive node functionality.

Adaptive Particle Filter for Data Fusion of Multiple Cameras

Occlusion is a difficult problem for visual tracking and we use multiple wide baseline cameras to deal with occlusion. We propose a data fusion approach for visual tracking using multiple cameras with overlapping fields of view. First, we present a spatial and temporal recursive Bayesian filter to fuse information from multiple cameras. An adaptive particle filter is formulated to realize the spatial and temporal recursive Bayesian filter. Our algorithm is able to recover the target’s position even under complete occlusion in a camera.

Methods for Compression of Feedback in Adaptive Multi-carrier 4G Schemes

In this paper, several algorithms for compressing the feedback of channel quality information are presented and analyzed. These algorithms are developed for a proposed adaptive modulation scheme for future multi-carrier 4G mobile systems. These strategies compress the feedback data and, used together with opportunistic scheduling, drastically reduce the feedback data rate. Thus the adaptive modulation schemes become more suitable and efficient to be implemented in future mobile systems, increasing data throughput and overall system performance.

Fast PWM-Based Test for High Resolution ΣΔ ADCs

This work describes a novel test strategy that uses digital stimuli for cheap, fast, though accurate, testing of high resolution ΣΔ ADCs. Simulations and measurements showed a discrimination threshold on specification parameters up to −90 dBc. The proposed method helps to reduce the cost of ADC production test, to extend test coverage and to enable built-in self-test and test-based self-calibration.

Hardware Implementation of Skeletonization Algorithm for Parallel Asynchronous Image Processing

This paper presents an FPGA realisation of an application-specific cellular processor array designed for asynchronous skeletonization of binary images. The skeletonization algorithm is based on iterative thinning utilizing a ‘grassfire’ transformation approach. The purpose of this work was to test the performance of a fully parallel asynchronous processor array and to evaluate the inhomogeneity of wave propagation velocity. A proof-of-concept design has been implemented and evaluated, the results are presented and discussed.

Channel Adaptive Power Control in the Uplink of CDMA Systems

In this paper, we propose an adaptive power control algorithm using optimal control theory for CDMA cellular systems. With linear quadratic control, each mobile transmits to achieve a desired SIR under the fast varying environment of practical CDMA cellular systems. We apply Kalman filter theory to estimate a channel variation which is vulnerable to nonconstant link gain, mutual interference and uncertain noise. Through simulation comparison with DCPC algorithm, the suggested power control algorithm shows an increased uplink channel capacity.

Very Low Energy Consumption Wireless Sensor Localization for Danger Environments with Single Mobile Anchor Node

In wireless sensor networks (WSN), it is very important for sensor nodes to locate with low energy consumption and high accuracy, especially in a dangerous environment. This paper describes a range-free layered localization scheme using one mobile anchor node which can transmit gradient signals, and whose moving track is a straight-line along the x-axis. And this paper proposes a sleep/wake mechanism called sensor sleep-time forecasting to save energy consumption during localization. The relationship, between the key factors in localization algorithm and the average location error, is analyzed in detail. Simulation results show that the scheme performs better than other range-free mechanisms—the average location error is less than 0.7 m, and it is independent on sensor nodes density or sensor nodes radio range, the accuracy of the algorithm can be adjusted in different occasions, and the algorithm beacon overhand is small and average localization time is short.

Role of Convergence in GIMCV Development: A Vision

Path to Global Information Multimedia Communication Village (GIMCV) can be seen as a convergence process among telephony, data exchange and television. Convergence refers not only to various services provided by the same operator but also by the same device, the same access network, the same transport network, etc. This paper present authors’ vision on how convergence will lead the GIMCV development.

Performance of MIMO System Through Nakagami Fading Channel with Arbitrary Fading Parameters

In this paper, the analytical and simulation results of the bit error rate (BER) performance for a multiple-input multiple-output (MIMO) system with an arbitrary number of transmit and receive antennas are developed for the uplink transmission. The fading channel is assumed to follow Nakagami-m distribution with correlation among branches. The BER is expressed in terms of Lauricella’s multivariate hypergeometric function for both independent and correlated antenna branches for BPSK system.

MGFs for Rayleigh Random Variables

Expressions are given for the moment generating functions of the Rayleigh and generalized Rayleigh distributions.