Generalized Selection Combining in Cognitive MIMO Relay Networks

We propose transmit antenna selection with receive generalized selection combining (TAS/GSC) in dual-hop cognitive decode-and-forward (DF) relay networks for reliability enhancement and interference relaxation. In this paradigm, a single antenna which maximizes the receive signal-to-noise ratio (SNR) is selected at the secondary transmitter and a subset of receive antennas with the highest SNRs are combined at the secondary receiver. To demonstrate the impact of multiple primary users on the cognitive relay network, we derive new closed-form expressions for the exact and asymptotic outage probability with TAS/GSC in the secondary network. Several important design insights are reached. We corroborate that the full diversity gain is achieved, which is entirely determined by the total number of antennas in the secondary network. The negative impact of the primary network on the secondary network is reflected in the SNR gain.

Multiuser Cognitive Relay Networks in the Presence of Direct Links

In this paper, we investigate a multiuser cognitive relay network with direct source-destination links and multiple primary destinations. In this network, multiple secondary users compete to communicate with a secondary destination assisted by an amplify-and-forward (AF) relay. We take into account the availability of direct links from the secondary users to the primary and secondary destinations. For the considered system, we select one best secondary user to maximize the received signal-to-noise ratio (SNR) at the secondary destination. We first derive an accurate lower bound of the outage probability, and then provide an asymptotic expression of outage probability in high SNR region. From the lower bound and the asymptotic expressions, we obtain several insights into the system design. Numerical and simulation results are finally demonstrated to verify the proposed studies.

Mitigating Cross-Network Interference in Cognitive Spectrum Sharing with Opportunistic Relaying

We examine the impact of primary and secondary interference on opportunistic relaying in cognitive spectrum sharing networks. In particular, new closed-form exact and asymptotic expressions for the outage probability of cognitive opportunistic relaying are derived over Rayleigh and Nakagami-m fading channels. Our analysis presents revealing insights into the diversity and array gains, diversity-multiplexing tradeoff, impact of primary transceivers' positions, and the optimal position of relays. We highlight that cognitive opportunistic relaying achieves the full diversity gain which is a product of the number of relays and the minimum Nakagami-m fading parameter in the secondary network. Furthermore, we confirm that the diversity gain reduces to zero when the peak interference constraint in the secondary network is proportional to the interference power from the primary network.

Ergodic Capacity of Cognitive TAS/GSC Relaying in Nakagami-m Fading Channels

We examine the impact of transmit antenna selection with receive generalized selection combining (TAS/GSC) for cognitive decode-and-forward (DF) relaying in Nakagami-m fading channels. We select a single transmit antenna at the secondary transmitter which maximizes the receive signal-to-noise ratio (SNR) and combine a subset of receive antennas with the largest SNRs at the secondary receiver. In an effort to assess the performance, we first derive the probability density function and cumulative distribution function of the end-to-end SNR using the moment generating function. We then derive new exact closed-form expression for the ergodic capacity. More importantly, by deriving the asymptotic expression for the high SNR approximation of the ergodic capacity, we gather deep insights into the high SNR slope and the power offset. Our results show that the high SNR slope is 1/2 under the proportional interference power constraint. Under the fixed interference power constraint, the high SNR slope is zero.

Justice for Victims before the International Criminal Court

Many prosecutors and commentators have praised the victim provisions at the International Criminal Court (ICC) as 'justice for victims', which for the first time include participation, protection and reparations. This book critically examines the role of victims in international criminal justice, drawing from human rights, victimology, and best practices in transitional justice.

Drawing on field research in Northern Uganda, Luke Moffet explores the nature of international crimes and assesses the role of victims in the proceedings of the ICC, paying particular attention to their recognition, participation, reparations and protection. The book argues that because of the criminal nature and structural limitations of the ICC, justice for victims is symbolic, requiring State Parties to complement the work of the Court to address victims' needs.

In advancing an innovative theory of justice for victims, and in offering solutions to current challenges, the book will be of great interest and use to academics, practitioners and students engaged in victimology, the ICC, transitional justice, or reparations.

Validation of a passive stereophotogrammetry system for imaging of the breast: A geometric analysis

The overall aim of this study was to assess the accuracy, reproducibility and stability of a high resolution passive stereophotogrammetry system to image a female mannequin torso, to validate measurements made on the textured virtual surface compared with those obtained using manual techniques and to develop an approach to make objective measurements of the female breast. 3D surface imaging was carried out on a textured female torso and measurements made in accordance with the system of mammometrics. Linear errors in measurements were less than 0.5 mm, system calibration produced errors of less than 1.0 mm over 94% over the surface and intra-rater reliability measured by ICC = 0.999. The mean difference between manual and digital curved surface distances was 1.36 mm with maximum and minimum differences of 3.15 mm and 0.02 mm, respectively. The stereophotogrammetry system has been demonstrated to perform accurately and reliably with specific reference to breast assessment. (C) 2011 IPEM. Published by Elsevier Ltd. All rights reserved.

Realising Justice for victims before the International Criminal Court

The International Criminal Court (ICC) has been celebrated for its innovative victim provisions, which enable victims to participate in proceedings, avail of protection measures and assistance, and to claim reparations. The impetus for incorporating victim provisions within the ICC, came from victims’ dissatisfaction with the ad hoc tribunals in providing them with more meaningful and tangible justice.1 The International Criminal Tribunals for the former Yugoslavia and Rwanda (ICTY/R) only included victim protection measures, with no provisions for victims to participate in proceedings nor to claim reparations at them. Developments in domestic and international law, in particular human rights such as the 1985 UN Declaration on Justice for Victims and the UN Guidelines on Remedy and Reparations, and transitional justice mechanisms, such as truth commissions and reparations bodies, have helped to expand the notion of justice for international crimes to be more attuned to victims as key stakeholders in dealing with such crimes.

With the first convictions secured at the ICC and the victim participation and reparation regime taking form, it is worth evaluating the extent to which these innovative provisions have translated into justice for victims. The first part of this paper outlines what justice for victims of international crimes entails, drawing from victimology and human rights. The second section surveys the extent to which the ICC has incorporated justice for victims, in procedural and substantive terms, before concluding in looking beyond the Court to how state parties can complement the ICC in achieving justice for victims. This paper argues that while much progress has been made to institutionalise justice for victims within the Court, there is much more progress needed to evolve and develop justice for victims within the ICC to avoid dissatisfaction of past tribunals.

On the MIMO Capacity with Residual Transceiver Hardware Impairments

Radio-frequency (RF) impairments in the transceiver hardware of communication systems (e.g., phase noise (PN), high power amplifier (HPA) nonlinearities, or in-phase/quadrature-phase (I/Q) imbalance) can severely degrade the performance of traditional multiple-input multiple-output (MIMO) systems. Although calibration algorithms can partially compensate these impairments, the remaining distortion still has substantial impact. Despite this, most prior works have not analyzed this type of distortion. In this paper, we investigate the impact of residual transceiver hardware impairments on the MIMO system performance. In particular, we consider a transceiver impairment model, which has been experimentally validated, and derive analytical ergodic capacity expressions for both exact and high signal-to-noise ratios (SNRs). We demonstrate that the capacity saturates in the high-SNR regime, thereby creating a finite capacity ceiling. We also present a linear approximation for the ergodic capacity in the low-SNR regime, and show that impairments have only a second-order impact on the capacity. Furthermore, we analyze the effect of transceiver impairments on large-scale MIMO systems; interestingly, we prove that if one increases the number of antennas at one side only, the capacity behaves similar to the finite-dimensional case. On the contrary, if the number of antennas on both sides increases with a fixed ratio, the capacity ceiling vanishes; thus, impairments cause only a bounded offset in the capacity compared to the ideal transceiver hardware case.

An Improvement of IP Address Lookup based on Rule Filter Analysis

Multi-bit trie is a popular approach performing the longest prefix matching for packet classification. However, it requires a long lookup time and inefficiently consumes memory space. This paper presents an in-depth study of different variations of multi-bit trie for IP address lookup. Our main aim is to study a method of data structure which reduces memory space. The proposed approach has been implemented using the label method in two approaches. Both methods present better results regarding lookup speed, update time and memory bit consumptions.

Energy-Aware Rate and Description Allocation Optimized Video Streaming for Mobile D2D Communications

The proliferation problem of video streaming applications and mobile devices has prompted wireless network operators to put more efforts into improving quality of experience (QoE) while saving resources that are needed for high transmission rate and large size of video streaming. To deal with this problem, we propose an energy-aware rate and description allocation optimization method for video streaming in cellular network assisted device-to-device (D2D) communications. In particular, we allocate the optimal bit rate to each layer of video segments and packetize the segments into multiple descriptions with embedded forward error correction (FEC) for realtime streaming without retransmission. Simultaneously, the optimal number of descriptions is allocated to each D2D helper for transmission. The two allocation processes are done according to the access rate of segments, channel state information (CSI) of D2D requester, and remaining energy of helpers, to gain the highest optimization performance. Simulation results demonstrate that our proposed method (named OPT) significantly enhances the performance of video streaming in terms of high QoE and energy saving.

Secure D2D Communication in Large-Scale Cognitive Cellular Networks with Wireless Power Transfer

In this paper, we investigate secure device-to-device (D2D) communication in energy harvesting large-scale cognitive cellular networks. The energy constrained D2D transmitter harvests energy from multi-antenna equipped power beacons (PBs), and communicates with the corresponding receiver using the spectrum of the cellular base stations (BSs). We introduce a power transfer model and an information signal model to enable wireless energy harvesting and secure information transmission. In the power transfer model, we propose a new power transfer policy, namely, best power beacon (BPB) power transfer. To characterize the power transfer reliability of the proposed policy, we derive new closed-form expressions for the exact power outage probability and the asymptotic power outage probability with large antenna arrays at PBs. In the information signal model, we present a new comparative framework with two receiver selection schemes: 1) best receiver selection (BRS), and 2) nearest receiver selection (NRS). To assess the secrecy performance, we derive new expressions for the secrecy throughput considering the two receiver selection schemes using the BPB power transfer policies. We show that secrecy performance improves with increasing densities of PBs and D2D receivers because of a larger multiuser diversity gain. A pivotal conclusion is reached that BRS achieves better secrecy performance than NRS but demands more instantaneous feedback and overhead.

Multiuser Scheduling for Cognitive MIMO with Channel Estimation Errors and Feedback Delay

A multiuser scheduling multiple-input multiple-output (MIMO) cognitive radio network (CRN) with space-time block coding (STBC) is considered in this paper, where one secondary base station (BS) communicates with one secondary user (SU) selected from K candidates. The joint impact of imperfect channel state information (CSI) in BS → SUs and BS → PU due to channel estimation errors and feedback delay on the outage performance is firstly investigated. We obtain the exact outage probability expressions for the considered network under the peak interference power IP at PU and maximum transmit power Pm at BS which cover perfect/imperfect CSI scenarios in BS → SUs and BS → PU. In addition, asymptotic expressions of outage probability in high SNR region are also derived from which we obtain several important insights into the system design. For example, only with perfect CSIs in BS → SUs, i.e., without channel estimation errors and feedback delay, the multiuser diversity can be exploited. Finally, simulation results confirm the correctness of our analysis.

Elaborating Justice for Victims at the International Criminal Court: Beyond Rhetoric and the Hague

Justice for victims has often been invoked as the raison d’être of international criminal justice, by punishing perpetrators of international crimes. This article attempts to provide a more holistic account of justice for victims by examining victims’ needs, interests, and rights. The International Criminal Court itself includes participation, protection and reparation for victims, indicating they are important stakeholders. This article also suggests that victims are integral to the purpose of the ICC in ending impunity by ensuring transparency of proceedings. However, there are limits to the resources and capacity of the ICC, which can only investigate and prosecute selected crimes. To overcome this justice gap, this article directs the debate towards a victim-orientated agenda to complementarity, where state parties and the Assembly of State Parties should play a greater role in implementing justice for victims domestically. This victim-orientated complementarity approach can be achieved through new ASP guidelines on complementarity, expanding universal jurisdiction, or seeking enforcement and cooperation through regional and international bodies and courts, such asUniversal Periodic Review or the African Court’s International Criminal Law Section. In the end, ifwe are serious about delivering justice for victims we need to move beyond the rhetoric, with realistic expectations of what the ICC can achieve, and concentrate our attention to what states should bedoing to end impunity.

Compressive Sensing based Detector for Sparse Signal Modulation in Precoded OFDM

In this paper, we propose a sparse signal modulation (SSM) method for precoded orthogonal frequency division multiplexing (OFDM) systems and study the signal detection. Although a receiver is able to exploit a path diversity gain with random precoding in OFDM, the complexity of the receiver is usually high as the orthogonality is not retained due to precoding. However, with SSM, we can derive a low-complexity detector that can provide reasonably good performances with a low sparsity ratio based on the notion of compressive sensing (CS). An important feature of a CS detector is that it can estimate SSM signals with a small fraction of the received signals over sub-carriers. This feature can allow us to build a low cost receiver with a small number of demodulators.

Meaningful and Effective? Considering Victims’ Interests Through Participation at the International Criminal Court

This article explores the role of victims in the criminal proceedings of the International Criminal Court and the extent to which their interests have impacted upon the ICC judges’ decision making in light of human rights law and victimological theorisation. The article begins by first outlining how victims’ interests can be considered in international criminal proceedings, before contrasting this role with the purpose of international criminal justice. The second part of the article examines victim participation within the ICC and how this has affected judicial decision making to assess its effectiveness. The contest between the rights of victims and the role of Prosecutor in determining the selection of charges and perpetrators is also examined in an effort to add to the current debate on victim participation at the ICC. The author finds that at the ICC, despite innovative victim provisions, victims’ interests have little impact on outcomes of the Court. The author argues that in order to ensure the Court is more responsive to victims understanding of justice it should give greater weight to their interests, which in turn is likely to improve their satisfaction with the ICC, as well as public confidence and legitimacy of the work of the Court.