Baseband Radio over Fiber Aided Millimeter-Wave Distributed Antenna for Optical/Wireless Integration

A Baseband Radio Over Fiber (BROF) architecture is proposed, where upto four Radio Frequency (RF) carriers can be generated, while using the heterodyne photo-detection of only two optical signals. This proposed BROF architecture has a star-like structure and it is composed of six Radio Access Units (RAUs), where data is transmitted from the Central Unit (CU) to the Base Station (BS) and from the BS to the RAU over a distance of 20 Km and 0.3 Km, respectively, at a rate of 768 Mbps. The performance of the system supporting four carrier frequencies drops by at most 1dB, at a BER of 10-9, compared to conventional heterodyne photo-detection

A Full-Duplex Diversity-Assisted Hybrid Analogue/Digitized Radio Over Fibre for Optical/Wireless Integration

A duplex Radio Over Fibre (ROF) ring architecture is proposed taking into account the constraints imposed by the cost of fibre laying and of the optical/electronic components, as well as the spectral efficiency and the duplex link performance. It has been shown that relying on Analogue ROF (AROF) and state-of-the-art Digitized ROF (DROF) architectures for downlink and uplink transmission, respectively, attains a high-integrity duplex performance. A sophisticated amalgam of Optical Carrier Suppression (OCS), Code Division Multiplexing (CDM), optical frequency multiplexing, Optical Carrier Reuse (OCR) and distributed antennas is conceived

Performance improvement and cost reduction techniques for radio over fiber communications

Advanced cost reduction and performance improvement techniques conceived for Radio Over Fiber (ROF) communications are considered. ROF techniques are expected to form the backbone of the future 5G generation of wireless networks. The achievable link performance and the associated deployement cost constitute the most salient metrics of a ROF architecture. In this paper, we commence by providing a rudimentary overview of the ROF architecture and then elaborate on ROF techniques designed for improving the attainable system performance. We conclude by describing the ROF techniques conceived for reducing the ROF system installation costs

Radio-over-Fiber Aided Base Station Coordination for OFDM

This proceding at: IEEE 80th Vehicular Technology Conference (VTC)Fall. Took place 2014, September 15-19, in Vancouver (Canada).Radio over Fiber (RoF) distribution aided co-operation of Remote Access Points (RAPs) is proposed for jointly transmitting data to the users in the downlink (DL) of a Multiple Input Multiple Output Orthogonal Frequency Division Multiplexing (MIMO-OFDM) system. Joint transmission is performed with the aid of Block Diagonalization (BD), where the transmitted signal is pre-distorted in order to overcome the non-linearity imposed by the optical modulator. We demonstrate that with adequate design, the users can obtain high data rates with very small degradation introduced by the RoF transmission. Quantitatively, when M=7 RAPs, each equipped with t=2 transmit antennas (TAs) each, cooperate to serve N=7 simultaneous users, also equipped with r=2 receive antennas (RAs), the SNR degradation is kept below 0.1 dB compared to a system assuming a perfect RoF channel. On the other hand, the SNR performance degradation is around 1.2 dB, when the number of antennas at the transmitters and the receivers is increased to t=r=8.This work was supported by projects CSD2008-00010, TEC2011-29006- C03-03 and by a mobility grant of Spanish Ministry of Education. The financial support of the UK Government’s Engineering & Physical Sciences Research Council (EPSRC) as well as that of the Research Councils UK (RCUK) and of the European Research Council’s Senior Research Fellow Grant is also gratefully acknowledged.Publicad

Quantitative abundance of amphipods around Andaman-Nicobar Islands

The present study deals with the quantitative distribution and abundance of amphipods of the Andaman Sea in time and space, based on the zooplankton samples collected during the cruises 46- 73 of FORV Sagar Sampada during 1988-1990. Mean number of amphipods (no/1000 m ) reached the maximum of 1763 in January and the minimum of 315 in July. The seasonal density was maximum during the northeast monsoon and minimum for the southwest monsoon and their mean numbers were estimated as 812 and 463/1000 m respectively. In general, they were abundant in the region where the station depths ranged between 50 and 100 m with the mean estimated as 800/1000 m of water. Analysis of day and night samples did not show any remarkable variation. The distribution and abundance of amphipods in relation to time and space are discussed in the paper

Efficacy of vaginal dilator use in preventing vaginal stenosis among cervical and endometrial cancer patients underwent radiotherapy

Background: Vaginal dilators (VD) are effective in the prevention of vaginal stenosis in patients undergoing pelvic radiotherapy for gynaecological malignancies. This study was aimed to assess the efficacy of VD use in preventing post radiotherapy vaginal stenosis in cervical and endometrial cancer patients.Methods: A cohort study was designed among patients (20-70 years) with biopsy proven endometrial and cervical carcinoma who underwent pelvic radiotherapy were included. Patients with cervical carcinoma (FIGO stage-IA to IVA), endometrial carcinoma (FIGO stage IB grade III, FIGO stage II), histology of squamous cell carcinoma, adenocarcinoma and performance score-ECOG 1 were included in the study. Assessment included clinical history, general examination, pelvic examination at 3 monthly intervals till 1 year. Grading of vaginal stenosis was assessed using LENT SOMA grading system.Results: A total of 42 patients with 20 patients using vaginal dilators and 22 patients who refused to use VD were assigned. It was effective for 60% of VD users compared to 20% of nonusers (p=0.007) at 9 months follow up. While at 12 months follow up, it was effective for 58% of VD users compared to 16.6% of nonusers (p=0.066). Percent adherence was maximum in the 1st and 2ndquarter and declined to 61% by the 4th quarter. The total adherence was 97%.Conclusions: There was 55% vs 22.7% effectiveness to prevent the vaginal stenosis among VD users.  All patients need proper counselling, motivation and support for regular usage of VD which will ultimately help in reducing the incidence of vaginal stenosis

In situ chemical oxidative polymerisation for ordered conducting polythiophene nanostructures in presence of dioctyl sodium sulfosuccinate

Polythiophenes (PTs) have been synthesized by chemical oxidative polymerization of thiophene in the presence of an anionic surfactant dioctyl sodium sulfosuccinate (AOT) using ferric chloride as an oxidant in chloroform solvent. Different monomer/surfactant ratios have been employed to study the effect of surfactant on synthesis and properties of polythiophenes. The PTs have been characterized by FT-IR spectroscopy, wide-angle powder X-ray diffraction and elemental analysis. The properties of PTs prepared using AOT surfactant have been compared with those of PT synthesized without surfactant. Four probe electrical conductivity measurements of the samples reveal that the conductivity is in the range of (7.4–1.0)×10-3 S cm-1 for AOT doped polythiophene samples. The band gap of the polymers determined from diffuse reflectance spectroscopy is in the range of 2.25–2.50 eV. Scanning electron microscopic images of the samples exhibited spherical nanoparticle morphology with size in the range of 800 ± 50 nm

Error vector magnitude analysis of fading SIMO channels relying on MRC reception

We analytically characterize the data-aided Error Vector Magnitude (EVM) performance of a Single Input Multiple Output (SIMO) communication system relying on Maximal Ratio Combining (MRC) having either independent or correlated branches that are non-identically distributed. In particular, exact closed form expressions are derived for the EVM in -? fading and -? shadowed fading channels and these expressions are validated by simulations. The derived expressions are expressed in terms of Lauricella’s function of the fourth kind F(N) D (.), which can be easily computed. Furthermore, we have simplified the derived expressions for various special cases such as independent and identically distributed branches, Rayleigh fading, Nakagamim fading and -? fading. Additionally, a parametric study of the EVM performance of the wireless system is presented

A Systems Engineering Approach to Modeling and Analysis of Chronic Obstructive Pulmonary Disease (COPD)

Chronic Obstructive Pulmonary Disease (COPD) is a progressive lung disease characterized by airflow limitation. This study develops a systems engineering framework for representing important mechanistic details of COPD in a model of the cardio-respiratory system. In this model, we present the cardio-respiratory system as an integrated biological control system responsible for regulating breathing. Four engineering control system components are considered: sensor, controller, actuator, and the process itself. Knowledge of human anatomy and physiology is used to develop appropriate mechanistic mathematical models for each component. Following a systematic analysis of the computational model, we identify three physiological parameters associated with reproducing clinical manifestations of COPD - changes in the forced expiratory volume (FEV), lung volumes, and pulmonary hypertension. We quantify the changes in these parameters (airway resistance, lung elastance, and pulmonary resistance) as the ones that result in a systemic response that is diagnostic of COPD. A multivariate analysis reveals that the changes in airway resistance have a broad impact on the human cardio-respiratory system, and that the pulmonary circuit is stressed beyond normal under hypoxic environments in most COPD patients.Comment: 25 pages, 15 figure