A low-complexity self-calibrating adaptive quadrature receiver

In this paper digital part of a self-calibrating quadrature-receiver is described, containing a digital calibration-engine. The blind source-separation-based calibration-engine eliminates the RF-impairments in real-time hence improving the receiver's performance without the need for test/pilot tones, trimming or use of power-hungry discrete components. Furthermore, an efficient time-multiplexed calibration-engine architecture is proposed and implemented on an FPGA utilising a reduced-range multiplier structure. The use of reduced-range multipliers results in substantial reduction of area as well as power consumption without a compromise in performance when compared with an efficiently designed general purpose multiplier. The performance of the calibration-engine does not depend on the modulation format or the constellation size of the received signal; hence it can be easily integrated into the digital signal processing paths of any receiver.

Community-led upgrading for self-reliance in informal settlements in South Africa: a review

Around the world, informal and low-income settlements (so-called “slums”) have been a major issue in city management and environmental sustainability in developing countries. Overall, African cities have an agenda for slum management and response. For example, the South African government introduced the Upgrade of Informal Settlements Program (UISP), as a comprehensive plan for upgrading slum settlements. Nevertheless, upgrading informal settlements from the bottom-up is key to inform broad protocols and strategies for sustainable communities and `adaptive cities´. Community-scale schemes can drive sustainability from the bottom-up and offer opportunities to share lessons learnt at the local level. Key success factors in their roll-out are: systems thinking; empowered local authorities that support decentralised solutions and multidisciplinary collaboration between the involved actors, including the affected local population. This research lies under the umbrella of sustainable bottom-up urban regeneration. As part of a larger project of collaboration between UK and SA research institutions, this paper presents an overview of in-situ participatory upgrade as an incremental strategy for upgrading informal settlements in the context of sustainable and resilient city. The motivation for this research is rooted in identifying the underpinning barriers and enabling drivers for up-scaling community-led, participatory upgrading approaches in informal settlements in the metropolitan area. This review paper seeks to provide some preliminary guidelines and recommendations for an integrated collaborative environmental and construction management framework to enhance community self-reliance. A theoretical approach based on the review of previous studies was combined with a pilot study conducted in Durban (South Africa) to investigate the feasibility of community-led upgrading processes.