Thesis (M.A.)--University of Wisconsin--Madison, 1952. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaf [65]).

Promotionsarbeit der Eidgenössischen Technischen Hochschule, Zürich. / Includes bibliographical references (p. 231-233).

Dissertation (Ph.D. in Philosophy in Electrical Engineering)--Naval Postgraduate School, June 2007. / Dissertation Advisor(s): John McEachen. "June 2007." Includes bibliographical references (p. 197-202). Also available in print.

Diss.--Phil. Fak.--Würzburg--Julius-Maximilians-Univ., 1999/2000. / Bibliogr. p. 287-310. Index.

The submission and commentary document an original and significant contribution to knowledge about the history, praxis and methods of how women have found their voice in community radio through participation at structural and symbolic levels; that is, by setting up their own radio station structures and programming, using community radio as a place to contest identity and produce new media narratives for themselves beyond male discourses. The submission finds that women’s community radio can be a place for individual empowerment, representation and creativity, as well as a space for resistance – including collective and transnational feminist campaigning and activism. The submission documents historical and contemporary case studies of feminist interventions and women’s radio programming in multiple global contexts. It demonstrates how this work has been instrumental in establishing the field of radio studies and within that, the sub-theme of women’s community radio practice. Discussion of methodologies of critical educational pedagogy runs throughout the commentary and demonstrates that specific, holistic, women-centred approaches to radio training and production can enable more women to access and participate in radio, thus raising the status of their on-air ‘voice’. It demonstrates that adoption and adaptation of the methodology of ethnographic and participatory action research in partnerships between community radio stations, women´s projects and voluntary organisations have developed new ways of understanding how women participate in and engage with radio and radio production. The submission is situated in the context of its intervention in current and recent debates about women´s public voice and the representation of women in media industries. It makes a significant contribution to knowledge about women’s community radio as part of radical and alternative cultural production and offers new directions for women´s radio practice, education and training.

The growth of Personal Communications, the keyword of the 90s, has already the signs of a technological revolution. The foundations of this revolution are currently set through the standardization of the Universal Mobile Telecommunication System (UMTS), a communication system with synergistic terrestrial and satellite segments. The main characteristic of the UMTS radio interface, is the provision of ISDN services. Services with higher than voice data rates require more spectrum, thus techniques that utilize spectrum as efficiently as possible are currently at the forefront of the research community interests. Two of the most spectrally efficient multiple access technologies, namely. Code Division Multiple Access (CDMA) and Time Division Multiple Access (TDMA) concentrate the efforts of the European telecommunity. This thesis addresses problems and. proposes solutions for CDMA systems that must comply with the UMTS requirements. Prompted by Viterbi's call for further extending the potential of CDMA through signal processing at the receiving end, we propose new Minimum Mean Square Error receiver architectures. MMSE detection schemes offer significant advantages compared to the conventional correlation based receivers as they are NEar FAr Resistant (NEFAR) over a wide range of interfering power levels. The NEFAR characteristic of these detectors reduces considerably the requirements of the power control loops currently found in commercial CDMA systems. MMSE detectors are also found, to have significant performance gains over other well established interference cancellation techniques like the decorrelating detector, especially in heavily loaded system conditions. The implementation architecture of MMSE receivers can be either Multiple-Input Multiple Output (MIMO) or Single-Input Single-Output. The later offers not only complexity that is comparable to the conventional detector, but also has the inherent advantage of employing adaptive algorithms which can be used to provide both the dispreading and the interference cancellation function, without the knowledge of the codes of interfering users. Furthermore, in multipath fading channels, adaptive MMSE detectors can exploit the multipath diversity acting as RAKE combiners. The later ability is distinctive to MMSE based receivers, and it is achieved in an autonomous fashion, without the knowledge of the multipath intensity profile. The communicator achieves its performance objectives by the synergy of the signal processor and the channel decoder. According to the propositions of this thesis, the form of the signal processor needs to be changed, in order to exploit the horizons of spread spectrum signaling. However, maximum likelihood channel decoding algorithms need not change. It is the way that these algorithms are utilized that needs to be revis ed. In this respect, we identify three major utilization scenarios and an attempt is made to quantify which of the three best matches the requirements of a UMTS oriented CDMA radio interface. Based on our findings, channel coding can be used as a mapping technique from the information bit to a more ''intelligent" chip, matching the ''intelligence" of the signal processor.

My thesis is a meta-theory that looks at the evolution, current status and possible futures of Radio Studies, largely through the detailed examination of a key concept: Intimacy. It brings together and puts into dialogue theories of radio that have previously appeared to be antithetical: in other words, (what I refer to as) mainstream radio theory and non-mainstream (or avant-garde) radio theory. I use the term 'mainstream' radio theory to designate the ideas and arguments set out in textbooks and other scholarly articles and monographs that seek to explain the historical development and the workings and meanings of radio broadcasting (contemporary and historical) across a variety of popular platforms, formats and genres. I use the terms 'non-mainstream' and 'avant-garde' radio theory, on the other hand, to designate a more abstract approach to theorizing radio art (and radio as art) that has been largely produced by radio practitioners reflecting critically upon their own experimental and avant-garde productions, many of which challenge the conventions of mainstream and commercial radio broadcasting. Situated within the margins of mainstream broadcasting, these theorist-practitioners often position themselves (as well as being positioned by others) as a counter-cultural minority, one moreover that refuses to be bound by either the conventions of radio techniques and formats or the conventions of academic writing. Consequently, this body of theory is often quite challenging, impenetrable, allusive and (darkly) poetic, which means that it is subject to various interpretations, misunderstandings and contradictions, as I will discuss in more detail in chapters one and two of this thesis. These non-mainstream theories are typically more alternative in both content and language, which is often designed to challenge any sense of complacency in thinking by disturbing the ontological and epistemological regimes that operate elsewhere in such disciplines as Radio Studies, Media Studies and Cultural Studies. Nevertheless, as I shall argue, these artist-writers and critical thinkers have many valuable insights to contribute to Radio Studies as a whole and one of my aims is to absorb their ideas and arguments more fully into my exploration of radio Intimacy, while simultaneously borrowing from them some of their methodologies.

La radio peruana revela una enorme diversidad, la que está en proporción directa con su multiculturalidad. Ambas características descubren un proceso en el que diversos actores sociales despliegan sus marcadas influencias y configuran un escenario complejo, pleno de oportunidades y retos. Más allá de la gran radio comercial capitalina están las otras radios: pequeñas empresas, provincianas, las pertenecientes a la iglesia o a los alcaldes e inclusive a micro empresarios, hijos de la melomanía folklórica. Las múltiples motivaciones producen un panorama con muchos tipos de radio que es preciso comenzar a conocer.

The Hartebeesthoek Radio Telescope is well suited to mapping large areas of sky at 2.3 GHz because of the stability and sensitivity of the noise-adding radiometer (Nicolson, 1970) and cryogenic amplifier used at this frequency, the relatively large 20' beam of the 26 m dish antenna, and its high-speed drive capability. Telescope control programs were written for the Observatory's online computer for automated mapping. Effort centred on removing the curved baseline or 'background' from each Declination (Dec) scan, due to atmospheric and ground radiation contributions varying as the antenna is scanned. Initially these backgrounds were measured over a wide range of Hour Angle (HA) for the Dec range of a map, and an interpolated curve subtracted from each on-source scan for its HA. A common base level was established by comparison with drift scans (observed with the antenna stationary). These different observations (on- and off-source Dec scans and drift scans) were combined into one in the Skymap system by performing Dec scans at a fixed starting HA for a period long enough to permit 'cold sky' and the source to drift through. A background formed by fitting a smooth curve through the lowest sample at each Dec provides a consistent relative base level for all the scans in an observation. A high scanning speed is used so that observations may fruitfully be repeated three times and interleaved to build a reliable, fully sampled map. As each observation has its own background removed, it may be made at any HA. For comparison, maps of Upper Scorpio produced by the earlier method (Baart et al., 1980) and the Magellanic Cloud region produced by Skymap (Mountfort et al., 1987) are shown. Skymap provides a simple and flexible mapping method which relies on the stability of the noise-adding radiometer and high-speed repeated scans to produce good maps of large or small extent with little computation. Correction for drift is more difficult than with systems which use intersecting scans, such as the 'nodding' scans used by Haslam et al. (1981) or the Azimuth scans of Reich (1982).

This thesis is a performance study of the paraboloidal antenna of the Dominion Radio Astrophysical Observatory and is an assessment of the quantity and distribution of radiation reaching the receiver input from all directions. This study deals first with the ideal reflector for which the radiation pattern is computed for small off-axis angles and for wide-angle radiation. The latter calculations make use of the stationary-phase principle in evaluating the radiation integrals. It has been found that the half-power beam-width is slightly more than 0.5° and the first side-lobe is at least 30 db down. In the following chapter, the surface imperfections of the reflector are considered, in addition to the radiation reaching the feed from the ground. The aperture field is divided into a number of zones perturbed slightly in phase so as to approximate the slowly-varying roughness of the reflector. The resulting increase in side-lobe level is then not only related to the surface tolerance, but to the average size of each zone. The radiation reaching the feed from the ground due to spillover, transmission through the reflector mesh and holes, and reflector surface loss, contributes about 16°K to the equivalent noise temperature of the antenna. The hollow dielectric spars supporting the feed horn are considered and are treated first as being infinite in length where the necessary boundary conditions are applied. The concept of scattering in cones about the cylinder axis is also developed. Then, for the finite cylinder, radiation is assumed to result from the same scattering width. Experimental studies are carried out and with Cassiopeia A as a source, the shape of the main beam is found to agree with the theoretical result, but the level of the first side-lobe is higher than expected. This discrepancy is believed to be due to reflector distortion. The sun is used as a source for detection of spar scattering and the presence of scattering cones is confirmed. An absolute temperature calibration is carried out with a resulting figure 27°K for the antenna pointed at the zenith. This temperature is measured at the input of a Dicke switch and is consistent with the theoretical 16°K presented to the input of the feed horn. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate