Parallel convolutional coder

A parallel convolutional coder (104) comprising: a plurality of serial convolutional coders (108) each having a register with a plurality of memory cells and a plurality of serial coder outputs,- input means (120) from which data can be transferred in parallel into the registers,- and a parallel coder output (124) comprising a plurality of output memory cells each of which is connected to one of the serial coder outputs so that data can be transferred in parallel from all of the serial coders to the parallel coder output

MIMO channel capacity and configuration selection for switched parasitic antennas

MIMO systems offer a significant enhancement of data rate and channel capacity compared to traditional systems. But correlation degrades the system performance and puts a practical limit on the number of antennas that can be squeezed into portable wireless devices. Switched Parasitic Antennas (SPAs) is a possible solution especially where it is difficult to obtain enough signal decorrelation with conventional means. The covariance matrix represents the correlation present in the propagation channel and has significant impact on the MIMO channel capacity. The results of this work demonstrate a significant improvement in the MIMO channel capacity by using SPA with the knowledge of the covariance matrix for all pattern configurations. By employing the ‘Water-Pouring Algorithm’ (WPA) to modify the covariance matrix, the channel capacity is significantly improved as compared to traditional systems which just spread power equally among all the transmit antennas. A Condition Number (CN) is also proposed as a selection metric, to select the optimal pattern configuration for SPAs. CN is a channel quality indicator which represents the Eigen Value Spread (EVS) of the covariance matrix

Assis – facilitating next generation learning experiences

The recent eLearning developments from the JISC have considered the provision of a Service Oriented Architecture (SOA), with the vision of enabling the aggregation of a number of discrete services in to a coherent whole for the end user. The Assis project, funded by the JISC and completed in March 2005, looked technically and pedagogically at how learning materials including formative assessment could be delivered by integrating simple sequencing and assessment. It is envisaged that the approach developed by the project can be used as the first steps in a move towards explorative and games-based learning. In order to translate this technical architecture into a concept both teachers and learners can engage with, it has become apparent that a higher level design paradigm is required. Assis explored the creation and development of a Floor-Corridor-Room model. The generation of such learning experiences also requires an interface allowing the searching, previewing and downloading of assessment items from a question bank. Assis created a common interface to Web Services based search services for two different assessment systems with item banks (TOIA and Samigo). At the core of Assis technical developments is the Player, a micro integration of discrete services to produce a service oriented tool. By communicating with a number of external services, the Player delivers structured dynamic packages of content to the user by the rendering and response processing of assessment items, processing the sequencing rules and providing additional, context sensitive resources. The presentation will include a demonstration of a simple adaptive sequence of content using the Player tool in conjunction with sequencing and assessment services. An intended future demonstrator in the field of archaeology, more closely aligned with the intention to create more explorative environments, will also be presented. To conclude, an examination of the effectiveness of the SOA approach will be considered, both in terms of creating and developing tools and the implications for potential future work by the JISC and others in the community

Reviews

Apolog

Dual carrier modulation soft demapper

An Orthogonal Frequency Division Multiplexing (OFDM) communication system with a transmitter and a receiver. The transmitter is arranged to transmit channel estimation sequences on each of a plurality of band groups, or bands, and to transmit data on each of the band groups or bands. The receiver is arranged to receive the channel estimation sequences for each band group or band to calculate channel state information from each of the channel estimation sequences transmitted on that band group or band and to form an average channel state information. The receiver receives the transmitted data, transforms the received data into the frequency domain, equalizes the received data using the channel state information, demaps the equalized data to re-construct the received data as soft bits and modifies the soft bits using the averaged channel state information

Wireless capsule gastrointestinal endoscopy: direction of arrival estimation based localization survey

One of the significant challenges in Capsule Endoscopy (CE) is to precisely determine the pathologies location. The localization process is primarily estimated using the received signal strength from sensors in the capsule system through its movement in the gastrointestinal (GI) tract. Consequently, the wireless capsule endoscope (WCE) system requires improvement to handle the lack of the capsule instantaneous localization information and to solve the relatively low transmission data rate challenges. Furthermore, the association between the capsule’s transmitter position, capsule location, signal reduction and the capsule direction should be assessed. These measurements deliver significant information for the instantaneous capsule localization systems based on TOA (time of arrival) approach, PDOA (phase difference of arrival), RSS (received signal strength), electromagnetic, DOA (direction of arrival) and video tracking approaches are developed to locate the WCE precisely. The current article introduces the acquisition concept of the GI medical images using the endoscopy with a comprehensive description of the endoscopy system components. Capsule localization and tracking are considered to be the most important features of the WCE system, thus the current article emphasizes the most common localization systems generally, highlighting the DOA-based localization systems and discusses the required significant research challenges to be addressed

Mapping the e-Learning Assessment Domain: Concept Maps for Orientation and Navigation

Concept or Topic Maps have long been used as a method of categorizing and organizing information about a domain. Building them can help people conceptualize an area and spot trends or gaps, and as a presentation method they quickly provide an overview and general impression of a space. We are currently constructing a Reference Model of the Assessment Domain that takes the form of a highly interlinked dynamic website. This represents the assessment domain via the software, projects, standards and use cases of which it is composed. In this paper we present our efforts to create complimentary concept maps of the assessment domain, not as an overview, but for navigation and orientation within the domain. These concept maps, which model resources and activities independently, have been corroborated with practitioners in the e-learning community