Joint space-time trellis decoding and channel estimation in correlated fading channels

This letter addresses the issue of joint space-time trellis decoding and channel estimation in time-varying fading channels that are spatially and temporally correlated. A recursive space-time receiver which incorporates per-survivor processing (PSP) and Kalman filtering into the Viterbi algorithm is proposed. This approach generalizes existing work to the correlated fading channel case. The channel time-evolution is modeled by a multichannel autoregressive process, and a bank of Kalman filters is used to track the channel variations. Computer simulation results show that a performance close to the maximum likelihood receiver with perfect channel state information (CSI) can be obtained. The effects of the spatial correlation on the performance of a receiver that assumes independent fading channels are examined.

Placing space/time through photography’s old and new technologies

The discovery that an impressively strong 3-dimensional effect in a 2-dimensional photographic representation of natural outdoor scenes occurs when a single camera is directed around one point in the scene, thus drawing into relief the subject of attention and blurring the surrounding space, has important implications for understanding basic processes in 3-dimensional vision. For the development of new ways for generating 3D effects in motion and static representations of scenes we might well learn from photography’s old technologies, as well as digital technologies of the static print, which have yet to release the full impact of their potential in the representation of motion and space.

Building movements : installations : space-time twister; the rub

The two collaborative installations are part of the Building Movements event and aim to generate a shared ‘body of actions’. We are proposing to emphasise attention to constructed environments (buildings, clothes, landscapes…) as active participants in ecologies of lived experience, with particular interest in how we can more explicitly approach our environments as spatial research devices, i.e. how constructed environments can offer key questions and provocations in any research enquiry.

Enchanting David Bowie space/time/body/memory

This exciting collection is organized according to the key themes of space, time, body, and memory - themes that literally and metaphorically address the key questions and intensities of his output.

Beating space and time: historical gay sex and queer cultural geographies of masculinities

This article focuses on historical queer cultural geographies of masculinities and to do so it focuses on two cases/places. The first is an archival case/place: a partial assembly of documents of beats and their uses during and in the wake of Gay Liberation in Australia. The second is a literary case/place: Thomas Mann's Death in Venice, a canonical twentieth-century imbrication of male homosexuality and geography. This article will seek to rationalize the mobilization of these two asynchronous cases/places through the insights that both afford, when brought together, for elaborating contributions that queer readings of Nietzsche can make to contemporary queer theories of space, time and masculinities.

Body, space and time in networked performance

This special issue of Liminalities has been compiled from the outcomes of the conference Remote Encounters: Connecting bodies, collapsing spaces and temporal ubiquity in networked performance held at the University of South Wales on the 11th and 12th of April 2013. By providing an overview of contributions to the issue this editorial aims to both introduce networked performance to a new readership and for those already practicing in the field assemble and present the interdisciplinary and transdisciplinary practice that can be considered as networked performance. Contributor's research themes, practice issues and their creative solutions are identified revealing common threads of enquiry running throughout the issue. In addition notable papers and performances from the conference that have not been included in this issue are discussed briefly.

MMSE precoder for unitary space–time codes in correlated time-varying channels

This letter addresses the problem of the design of a precoder for multiple transmit antenna communication systems with spatially and temporally correlated fading channels. By using the asymptotic (high signal-to-noise ratio) mean-square error of the channel estimates, the letter derives a precoder for unitary space-time codes that can exploit the spatiotemporal correlation in the time-varying fading channels. Simulation results illustrate that significant performance gains can be achieved by using the new precoder.

On the problem of algebraic completeness for the invariants of the Riemann tensor. III.

We study the set CZ of invariants [Zakhary and Carminati, J. Math. Phys. 42, 1474 (2001)] for the class of space-times whose Ricci tensors possess a null eigenvector. We show that all cases are maximally backsolvable, in terms of sets of invariants from CZ, but that some cases are not completely backsolvable and these all possess an alignment between an eigenvector of the Ricci tensor with a repeated principal null vector of the Weyl tensor. We provide algebraically complete sets for each canonically different space-time and hence conclude with these results and those of a previous article [Carminati, Zakhary, and McLenaghan, J. Math. Phys. 43, 492 (2002)] that the CZ set is determining or maximal.

Precoder design for multi-antenna systems with temporally and spatially correlated fading channels

This paper addresses the problem of the design of a precoder for multiple transmit antenna communication systems with spatially and temporally correlated fading channels. Using the theories of matrix differential calculus, the paper derives a precoder for unitary space-time codes that can exploit the spatio-temporal correlation in the time-varying fading channels. The design criterion is based on minimizing the mean square error of the channel estimates. Computer simulation results show that a significant performance gain can be achieved by using the designed precoder.

Differential encoding technique for multi-antenna systems with correlated Rayleigh fading channels

Differential space-time modulation (DSTM) techniques developed for multi-antenna systems allow the receiver to detect the transmitted signal without the knowledge of the fading channels. It can be viewed as an extension of differential phase-shift keying (DPSK) in single antenna systems. In this paper, we derived the pairwise error probability upper bound of differential space-time coded systems with spatially correlated Rayleigh fading channels. Based on the performance analysis, we develop a novel DSTM scheme which can exploit the spatial correlation in the fading channels. It is found that by carefully designing the initial transmitted signal matrix, the performance of the differential space-time coded systems can be significantly improved.

Seeking mechanisms for improved integration of biodiversity issues in regional natural resource management planning

This article reviews the literature on natural resource management (NRM) planning in Australia, with particular consideration given to exploring how regions might better integrate biodiversity conservation into catchment or regional planning in ways that lead to improved biodiversity conservation practice in the field. Many of the findings of the review are generic, affecting a range of NRM issues (including biodiversity conservation) and the NRM planning process itself, whilst other findings are specific to conservation of biodiversity. Factors affecting the integration of biodiversity include the organizational characteristics of the regional NRM body, clarity in the region of the responsibilities across the three tiers of government, effective participation of stakeholders, existence of detailed NRM plans that include sound biodiversity data and management principles, access to interpreted information, use of a mix of policy instruments capable of delivering biodiversity goals, and effective monitoring frameworks and tools to track the return on investment. there is considerable variability in the ways that NRM planning is practiced across Australia, at the enterprise, regional or catchment levels. However, an overarching issue is how well the planning caters for differences across space, time and human values and this article attempts to identify the considerations that impact on that requirement.