VLSI Implemented ML Joint Carrier Phase and Timing Offsets Joint Estimator for QPSK/QQPSK Burst Modems

A high performance ASIC supporting multiple modulation, error correction, and frame formats is under development at Hughes Network Systems, Inc. Powerful and generic data-aided (DA) estimators are needed to accommodate operation in the required modes. In this paper, a simplified DA maximum likelihood (ML) joint estimator for carrier phase and symbol timing offset for QPSK/OQPSK burst modems and a sample systolic VLSI implementation for the estimator are presented. Furthermore, the Cramer-Rao lower bound (CRLB) for DA case is investigated. The performance of the estimator is shown through simulation to meet the CRLB even at low signal-to-noise ratios (SNR). Compared with theoretical solutions, the proposed estimator is less computationally intensive and is therefore easier to implement using current VLSI technology. IEEE Wireless Communications and Networking Conference: WCNC'9

VLSI Implemented Data-Aided ML Parameter Estimators of PSK Burst Modems

A high performance Universal Modem ASIC that supports several modulation types and burst mode frame formats is under development. The ASIC is designed to work under stringent conditions such as large carrier frequency offset (up to 13 percent symbol rate) and low signal-to-noise ratio (SNR). Powerful and generic data-aided (DA) parameter estimators are necessary to accommodate many modes. In this paper we present an approximated maximum likelihood (ML) carrier frequency offset estimator, ML joint carrier phase and timing offsets estimator and their systolic VLSI implementations for PSK burst modems. The performances are close to the Cramer-Rao lower bounds (CRLB) at low SNRs. Compared with theoretical solutions the estimators proposed here are much simpler and easier to implement by the current VLSI technology.VTC'99</i

Data-Aided ML Parameter Estimators of PSK Burst Modems and Their Systolic VLSI Implementations

A high performance Universal Modem ASIC that supports several modulation types and burst mode frame formats is under development. Powerful and generic data-aided (DA) parameter estimators are necessary to accommodate many modes. In this paper we present an approximated maximum likelihood (ML) carrier frequency offset estimator, ML joint carrier phase and timing offsets estimator and their systolic VLSI implementations for PSK burst modems. The performances are close to the Cramer-Rao lower bounds (CRLB) at low SNRs. Compared with theoretical solutions, the estimators proposed here are much simpler and easier to implement by the current VLSI technology. The CRLB for DA estimations is discussed in some depth, some issues on training sequence design is also addressed in this work.Globecomm99</i

The incidence of urogenital Chlamydia trachomatis infections among patients in Kumasi, Ghana

The incidence of urogenital chlamydia infections among selected patients in Kumasi, Ghana was evaluated using an immunofluorescent monoclonal antibody technique. Chlamydia trachomatis was identified in 4 of 110 patients presenting for prenatal care, 2 of 55 female patients with infertility and 6 of 15 males with acute urethritis. The findings demonstrate that C. trachomatis is a frequently identified pathogen among male patients presenting with symptoms of acute urethritis; however, the incidence of chlamydia infections among asymptomatic patients is relatively low.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27043/1/0000032.pd

Comparing factors associated with intimate partner violence among rural and urban women in Northern Uganda

Intimate partner violence (IPV) is an important public health issue with negative effects at individual and societal levels. In northern Uganda, IPV prevalence is high but literature on it is limited. Northern Uganda has a long history of socio-economic and political upheavals, which are recognized risk factors for IPV. We compare IPV prevalence among rural and urban women in northern Uganda. This was a cross-sectional survey of 856 northern Ugandan women, 409 women living in rural areas, and 447 women working in an urban marketplace. Data were analyzed using logistic regression. High rates of emotional, physical, and sexual IPV were found. Almost four of five participants had experienced at least one type of IPV during their lifetime, and approximately half of the participants had experienced IPV in the 12 months prior to the survey. Many women stated that IPV was justified in certain situations. Younger age was a significant determinant of IPV in both cohorts (adjusted odds ratio [aOR] 0.95, 95% confidence interval [CI] [0.93–0.97]). Determinants of IPV among the rural cohort included male partner’s alcohol abuse (aOR 2.22, CI [1.34–3.73]); having been in a physical fight with another man (aOR 1.90, 95% CI [1.12–3.23]); and controlling behaviors (aOR 1.21, CI [1.08–1.36]). Possible protective factors in the urban cohort included markers of economic empowerment such as being the decision maker on large household items (59.2% vs. 44.6%, p = .002) and having a mobile phone (20.4% vs. 12.4%, p = .024). Our study shows that IPV is a significant issue in northern Uganda. Economic empowerment is associated with lower rates of IPV in urban women, and interventions to reduce gender wealth inequality may reduce IPV prevalence. Further studies on enablers of IPV and the effect of conflict on IPV prevalence are needed to inform future interventions

Hamstring muscles: Architecture and innervation

Knowledge of the anatomical organization of the hamstring muscles is necessary to understand their functions, and to assist in the development of accurate clinical and biomechanical models. The hamstring muscles were examined by dissection in six embalmed human lower limbs with the purpose of clarifying their gross morphology. In addition to obtaining evidence for or against anatomical partitioning ( as based on muscle architecture and pattern of innervation), data pertaining to architectural parameters such as fascicular length, volume, physiological cross-sectional area, and tendon length were collected. For each muscle, relatively consistent patterns of innervation were identified between specimens, and each was unique with respect to anatomical organization. On the basis of muscle architecture, three regions were identified within semimembranosus. However, this was not completely congruent with the pattern of innervation, as a primary nerve branch supplied only two regions, with the third region receiving a secondary branch. Semitendinosus comprised two distinct partitions arranged in series that were divided by a tendinous inscription. A singular muscle nerve or a primary nerve branch innervated each partition. In the biceps femoris long head the two regions were supplied via a primary nerve branch which divided into two primary branches or split into a series of branches. Being the only muscle to cross a single joint, biceps femoris short head consisted of two distinct regions demarcated by fiber direction, with each innervated by a separate muscle nerve. Architecturally, each muscle differed with respect to parameters such as physiological cross-sectional area, fascicular length and volume, but generally all partitions within an individual muscle were similar in fascicular length. The long proximal and distal tendons of these muscles extended into the muscle bellies thereby forming elongated musculotendinous junctions. Copyright (C) 2005 S. Karger AG, Basel

Comparative nuclear effects of biomedical interest. Civil effects study

Selected physical and biological data bearing upon the environmental variations created by nuclear explosions are presented in simplified form. Emphasis is placed upon the ``early`` consequences of exposure to blast, thermal radiation, and ionizing radiation to elucidate the comparative ranges of the major effects as they vary with explosive yield and as they contribute to the total hazard to man. A section containing brief definitions of the terminology employed is followed by a section that utilizes text and tabular material to set forth events that follow nuclear explosions and the varied responses of exposed physical and biological materials. Finally, selected quantitative weapons-effects data in graphic and tabular form are presented over a wide range of explosive yields to show the relative distances from Ground Zero affected by significant levels of blast overpressures, thermal fluxes, and initial and residual penetrating ionizing radiations. However, only the ``early`` rather than the ``late`` effects of the latter are considered

Message in a Metro: Building Urban Rail Infrastructure and Image in Delhi, India

The world over, infrastructure mega projects have become more prevalent, even as evidence suggests that such projects often experience significant cost overruns while failing to fully deliver on their projected benefits. In this light, this article will argue that continued support for infrastructure mega projects stems from the way that such projects are presented to the public. Using the case of the development of a metro railway in Delhi, India, it shows that galvanizing public support and attracting patrons to a public transit system stems from creating an all-round positive image that combines tangible variables with an intangible set of symbolic meanings. Of course, image is only an impression, and does not necessarily reflect reality. In this light, the final section of this article examines the broad physical and societal implications of the metro development in Delhi, and uncovers the driving forces behind the project. The article concludes that, in spite of the cultivation of a positive image, the specific metro form that was developed in Delhi to satisfy each of the special interest groups involved in its production might be specifically one that fails to suit the transportation needs of the city. Copyright (c) 2006 The Author. Journal Compilation (c) 2006 Joint Editors and Blackwell Publishing Ltd.