Research

Crest Factor Reduction of an OFDM/WiMAX Network

By Sheila Mugala, Julius Butime, and Dorothy Okello (June 2012, Department of Electrical and Computer Engineering, School of Engineering, Art, Design and Technology (CEDAT), Makerere University, Uganda )

African countries lag behind the rest of the world in their use of Information and Communication Technologies (ICTs). To reduce the digital divide quickly and cost-effectively, wireless networks are considered. WiMAX (Worldwide Interoperability for Microwave Access) is a wireless broadband access technology that uses Orthogonal Frequency Division Multiplexing (OFDM) which is a multicarrier modulation scheme. OFDM presents a problem of a high crest factor or Peak to Average Power Ratio (PAPR). To circumvent this problem either High Power Amplifiers (HPAs) with large dynamic range or PAPR reduction techniques are used. The former scheme increases cost of the system while the latter introduces redundancy or distortion. A novel PAPR reduction scheme is presented. It is a combination of the ideas of Tone Reservation and Selected Mapping. The advantage of this scheme is that it has a lower complexity. It is simulated for a WiMAX system.

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Human rights and the internet - A review of perceptions in human rights organisations

By David Souter (March 2012, APC )

This report, commissioned by the Association for Progressive Communications (APC), is concerned with the relationship between human rights and the internet; and with perceptions of the internet, its impact on human rights and the concept of internet rights within mainstream rights organisations. It pays particular attention to the rights encapsulated in Articles 18, 19 and 20 of the Universal Declaration of Human Rights (freedoms of conscience, expression and association). The study forms part of APC’s work on internet rights and freedom of expression and, in particular, the “Internet rights are human rights” project.

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Assessment of citizens’ perceptions on open governance in Uganda

By APC and CIPESA (April 2012, APC )
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Open government data readiness study in Uganda

By APC and CIPESA (April 2012, APC )
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Application of ICTs for climate change adaptation in the water sector (Executive Summary)

By Alan Finlay and Edtih Adera (May 2012, APC and IDRC )

This collection of reports looks at how ICTs can be used to help communities in developing countries facing water stress adapt to climate change by from an ICT4D perspective.

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Voices from digital spaces: Technology-related violence against women

By APC WNSP (November 2011, APC )
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Spectrum use in Latin America: Summary report of the case studies of Argentina, Brazil, Colombia, Ecuador, Peru and Venezuela

By Carlos A. Afonso (November 2011, APC )

In Latin America case studies were done in Argentina, Brazil, Colombia, Ecuador, Peru and Venezuela. This report reviews and summarises the most relevant aspects of these studies.

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Evaluation of Global Information Society Watch 2007-2010

By Debbie Budlender (August 2011, APC )
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Chakula, an African ICT policy newsletter: Past editions

By APC (October 2011, APC )
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Digital broadcast migration in West Africa: Ghana workshop report

By Tanko Mohammed (June 2011, APC and Balancing Act )

The Ghana analog to digital migration workshop brought together almost 40 key stakeholders from the different sectors and provided them with key information of the mandated migration and educated them of the urgency, consequences, cost and strategies that could be taken during this initiative.

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