1,720,979 research outputs found
DS-CDMA REVERSE LINK CHANNEL ASSIGNMENT BASED ON INTERFERENCE MEASUREMENTS
No full textThe authors propose a DS-CDMA reverse link channel assignment algorithm based on received interference. A new channel is assigned if the required power is less than the 'current interference margin'. The proposed algorithm is adaptable to dynamically changing environments with the capability of assigning more channels than conventional channel assignment methods in nonhomogeneous traffic loads and path loss changes
The required signal power for multimedia traffic in multipath faded CDMA systems
No full textThe reverse link signal power required for multimedia traffic in multipath faded single-code (SC-) and multi-code CDMA (MC-CDMA) systems is investigated. The effect of orthogonality loss among multiple spreading code channels is characterized by introducing the orthogonality factor. The required signal power in both CDMA systems is analyzed with varying system parameters of spreading bandwidth, the orthogonality factor, and the number of spreading codes. Analytical results show that MC-CDMA users transmitting only a single traffic type require significantly more power than SC-CDMA users with only a single traffic type. On the other hand, MC-CDMA users transmitting multimedia traffic require power levels approximately identical to SC-CDMA users with multimedia traffic
Interference-based channel assignment for DS-CDMA cellular systems
No full textLink capacity is defined as the number of channels available in a link, In direct-sequence code-division multiple-access (DS-CDMA) cellular systems, this is limited by the interference present in the link. The interference is affected by many environmental factors, and, thus, the link capacity of the systems varies with the environment. Due to the varying link capacity, static channel assignment (SCA) based on fixed link capacity is not fully using the link capacity. This paper proposes a more efficient channel assignment based on the interference received at the base station (BS), In the proposed algorithm, a channel is assigned if the corresponding interference margin is less than the allowed interference, and, thus, channels are assigned adaptively to dynamically varying link capacity, Using the proposed algorithm yields more channels than using SCA in such an environment changes with nonhomogeneous traffic load or varying radio path loss, The algorithm also improves service grade by reserving channels for handoff calls
Link capacity and signal power according to allocations of spreading codes and bandwidth in CDMA systems
No full textReverse link performance analysis in single-code and multi-code CDMA systems is presented. Results show that the single-code system yields better performance than does the multi-code system in terms of link capacity and signal power. This improvement increases as spreading bandwidth is reduced and the number of spreading codes assigned to a user is increased
Effect of Bandwidth and Spreading Codes on Spectrum Utilization of Spectrally Overlaid CDMA Systems
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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