Parallel decoding of turbo codes using multi-point trellis termination and collision-free interleavers

The UMTS turbo encoder is composed of parallel concatenation of two Recursive Systematic Convolutional (RSC) encoders which start and end at a known state. This trellis termination directly affects the performance of turbo codes. This paper presents performance analysis of multi-point trellis termination of turbo codes which is to terminate RSC encoders at more than one point of the current frame while keeping the interleaver length the same. For long interleaver lengths, this approach provides dividing a data frame into sub-frames which can be treated as independent blocks. A novel decoding architecture using multi-point trellis termination and collision-free interleavers is presented. Collision-free interleavers are used to solve memory collision problems encountered by parallel decoding of turbo codes. The proposed parallel decoding architecture reduces the decoding delay caused by the iterative nature and forward-backward metric computations of turbo decoding algorithms. Our simulations verified that this turbo encoding and decoding scheme shows Bit Error Rate (BER) performance very close to that of the UMTS turbo coding while providing almost %50 time saving for the 2-point termination and %80 time saving for the 5-point termination.

Increasing the speed of parallel decoding of turbo codes

Turbo codes experience a significant decoding delay because of the iterative nature of the decoding algorithms, the high number of metric computations and the complexity added by the (de)interleaver. The extrinsic information is exchanged sequentially between two Soft-Input Soft-Output (SISO) decoders. Instead of this sequential process, a received frame can be divided into smaller windows to be processed in parallel. In this paper, a novel parallel processing methodology is proposed based on the previous parallel decoding techniques. A novel Contention-Free (CF) interleaver is proposed as part of the decoding architecture which allows using extrinsic Log-Likelihood Ratios (LLRs) immediately as a-priori LLRs to start the second half of the iterative turbo decoding. The simulation case studies performed in this paper show that our parallel decoding method can provide %80 time saving compared to the standard decoding and %30 time saving compared to the previous parallel decoding methods at the expense of 0.3 dB Bit Error Rate (BER) performance degradation.

Governing through community? A comparative study of changing management practices in mixed tenure housing development

An important feature of UK housing policy has been the promotion of consortia between local authorities, private developers and housing associations in order to develop mixed tenure estates to meet a wide range of housing needs. Central to this approach has been a focus on the management of neighbourhoods, based on the assumption that high densities and the inter-mixing of tenure exacerbates the potential for incivility and anti-social behaviour and exerts a disproportionate impact on residents' quality of life. Landlord strategies are therefore based on a need to address such issues at an early stage in the development. In some cases community-based, third sector organisations are established in order to manage community assets and to provide a community development service to residents. In others, a common response is to appoint caretakers and wardens to tackle social and environmental problems before they escalate and undermine residents’ quality of life. A number of innovative developments have promoted such neighbourhood governance approaches to housing practice by applying community development methods to address potential management problems. In the process, there is an increasing trend towards strategies that shape behaviour, govern ethical conduct, promote aesthetic standards and determine resident and landlord expectations. These processes can be related to the wider concept of governmentality whereby residents are encouraged to become actively engaged in managing their own environments, based on the assumption that this produces more cohesive, integrated communities and projects positive images. Evidence is emerging from a number of countries that increasingly integrated and mutually supportive roles and relationships between public, private and third sector agencies are transforming neighbourhood governance in similar ways. This paper will review the evidence for this trend towards community governance in mixed housing developments by drawing on a series of UK case studies prepared for two national agencies in 2007. It will review in particular the contractual arrangements with different tenures, identify codes and guidelines promoting 'good neighbour' behaviour and discuss the role of community development trusts and other neighbourhood organisations in providing facilities and services, designed to generate a well integrated community. The second part of the paper will review evidence from the USA and Australia to see how far there is a convergence in this respect in advanced economies. The paper will conclude by discussing the extent to which housing management practice is changing, particularly in areas of mixed development, whether there is a convergence in practice between different countries and how far these trends are supported by theories of governmentality.

The continuing popularity of the neighbourhood and neighbourhood governance in the transition from the 'big state' to the 'big society' paradigm

The neighbourhood in both the UK and Europe continues to dominate thinking about the quality of life in local communities, representation and empowerment, and how local services can be delivered most effectively. For several decades a series of centrally funded programmes in neighbour- hood governance have targeted localities suffering deprivation and social exclusion in England. From these much can be learnt about the strengths and limitations of a local approach to achieving multiple objectives.We review the findings of a case study of neighbourhood governance in the City of Westminster and draw on evaluations of two national programmes. In the conclusions we discuss the problems arising from multiple objectives and examine the prospects for neighbourhood governance as the national paradigm moves away from `big state' solutions towards the less-well-defined `big society' approach and the reinvention of `localism'. While the rationale for neighbourhood governance may change, the `neighbourhood' as a site for service delivery and planning remains as important now as in the past.

Can the state empower communities through localism? An evaluation of recent approaches to neighbourhood governance in England

‘Empowerment’ is a term much used by policy-makers with an interest in improving service delivery and promoting different forms of neighbourhood governance. But the term is ambiguous and has no generally accepted definition. Indeed, there is a growing paradox between the rhetoric of community empowerment and an apparent shift towards increased centralisation of power away from the neighbourhood in developed economies. This article explores the literature relating to empowerment and identifies two broad conceptions which reflect different emphases on neo-liberalism. It goes on to discuss two models illustrating different levels of state intervention at the neighbourhood level and sets out evidence from two neighbourhood councils in Milton Keynes in central England. In conclusion, it is argued that those initiatives which are top-down, state-led policy initiatives tend to result in the least empowerment (as defined by government), whereas the bottom-up, self-help projects, which may be partly state-enabled, at least provide an opportunity to create the spaces where there is some potential for varying degrees of transformation. Further empirical research is needed to test how far localist responses can challenge constraints on empowerment imposed by neo-liberalism.

The potential for neighbourhood regeneration in a period of austerity: changing forms of neighbourhood governance in two cities

Localism is an active political strategy, developed in a period of austerity by the UK's coalition government as a justification for the restructuring of state-civil society relationships. The deprived neighbourhood has long been a site for service delivery and a scale for intervention and action, giving rise to a variety of forms of neighbourhood governance. Prior international comparative research indicated convergence with the US given the rise of the self-help conjuncture and the decline of neighbourhood governance as a medium of regeneration. The subsequent shift in the UK paradigm from ‘big’ to ‘small state’ localism and deficit-reducing cuts to public expenditure confirm these trends, raising questions about the forms of neighbourhood governance currently being established, the role being played by local and central government, and the implications for neighbourhood regeneration. Two emerging forms of neighbourhood governance are examined in two urban local authorities and compared with prior forms examined in earlier research in the case study sites. The emerging forms differ significantly in their design and purpose, but as both are voluntary and receive no additional funding, better organised and more affluent communities are more likely to pursue their development. While it is still rather early to assess the capacity of these forms to promote neighbourhood regeneration, the potential in a period of austerity appears limited. Reduced funding for local services increases the imperative to self-help, while rights to local voice remain limited and the emerging forms provide little scope to influence (declining) local services and (still centralised) planning decisions, especially in neighbourhoods with regeneration needs which are likely to lack the requisite capacities, particularly stores of linking social capital. Initial conclusions suggest greater polarity and the further containment of deprived neighbourhoods.

Community empowerment or a strategy of containment? Evaluating neighbourhood governance in the city of Westminster

The longstanding emphasis on the neighbourhood as a scale for intervention and action has given rise to a variety of forms of governance with a number of different rationales. The predominant rationales about the purpose of neighbourhood governance are encapsulated in a fourfold typology developed by Lowndes and Sullivan (2008). This article sets out to test this approach by drawing on an evaluation of neighbourhood initiatives in the City of Westminster which were delivered through a third sector organisation, the Paddington Development Trust. ‘Insider’ perspectives gathered at city and neighbourhood levels regarding the infrastructure for neighbourhood management are discussed and evaluated in the light of these rationales. The conclusions, while broadly reflecting Lowndes and Sullivan and a follow-up study of Manchester, suggest that in Westminster the civic and economic rationales tend to predominate. However, the Westminster approach is contingent on the prevailing ethos and funding regimes at central and local levels and remains relatively detached from mainstream services. While community empowerment is an important part of the policy rhetoric, it is argued that in practice a ‘strategy of containment’ operates whereby residents in the neighbourhoods have relatively little control over targets and resources and that new governance mechanisms can be relatively easily de-coupled when required. In retrospect, co-production might have been a more effective model for neighbourhood governance, not least given its fit with policy direction.

Decentralization and Governance in Indonesia

Indonesia, over the past two decades, has embarked on a process of decentralization as part of a broader process of democratization, which followed earlier periods of centralized governance and authoritarian rule across the archipelago. The purpose of this book is to explore the connections between governance and sustainable society in a wide variety of policy fields in Indonesia,Indonesia and how reforming governance structures may contribute to societal benefits and the creation of a long-term sustainable society. The structures created may be characterized as a variable form of multi-governance, with varying types of relationships between the central government and newly empowered local governments.

National Policies for Local Urban Sustainability: A New Governance Approach?

Cities have become a focal point for efforts to transition towards a more sustainable, low-carbon society, with many municipal agencies championing ‘eco city’ initiatives of one kind or another. And yet, national policy initiatives frequently play an important – if sometimes overlooked – role, too. This chapters provides comparative perspectives on four recent national sustainable city programmes from France, India, Japan, and the United Kingdom. The analysis reveals two key insights: first, national policy is found to exercise a strong shaping role in what sustainable development for future cities is understood to be, which helps explain the considerable differences in priorities and approaches across countries. Second, beyond articulating strategic priorities, national policy may exercise a ‘soft’ governance function by incentivising and facilitating wider, voluntary governance networks in the effort to implement sustainable city projects locally. This innovative role, however, depends on the ability of national policy to produce resonance among societal actors and on its effective interaction with formal planning processes.