scholarly journals Experimental Circuit Model for Increasing the Signal Strength level of a Mobile Phone into a Lift

Due to rapid change in human lifestyle in recent years, the demand for constructing a building is very high. On the other hand due to the construction of buildings the signal strength level into the lift of that building is very low which is known as the transmission path loss. Path loss may be arising due to reflection, refraction and scattering. Path loss is a function of frequency and time. An innovative circuit model is developed for predicting wireless signal coverage into the lift. In this paper, we propose a simulated circuit model to reduce the penetration loss based on the measurement of window size, temperature, and humidity conditions etc. An outdoor antenna is used to receive the electromagnetic signals from the surrounding environment. The received signals are oscillated by the oscillator circuit. After this, it is amplified and converted into an optical signal. For better performance, this signal is transmitted through the optical fiber. The optical fiber is entered into the wire which is used to move (up-down) the lift. At the last end of the fiber, it is connected to a device which converts this optical signal into an electrical signal. This signal is sent to the indoor model and after amplifying the signal it is transmitted through the indoor antenna. The mobile phone antenna receives that signal and finally it is amplified and sent to the speaker of the mobile phone. This model works on 4G/3G/2G networks. Our model enhanced the signal strength level in the lift, which is the same outside the lift. It also measured that the signal strength level was the same at the top and ground floor. Required transmitting power is lower than previous methods

2021 ◽  
Vol 9 ◽  
Author(s):  
Jiaoli Liu ◽  
Jinyuan Wang ◽  
Bingyuan Zhang ◽  
Qinglin Wang

In this article, the secrecy performance of a hybrid radio frequency (RF)/visible light communication (VLC) system is studied. In this hybrid system, the source node (i.e., Alice) transmits information to the relay node via the outdoor RF link. Nakagami-m fading and path loss are considered for the RF link. The relay node includes an outdoor component and an indoor component, which are connected by using a wired medium. The outdoor component receives and recovers information by using the decode-and-forward (DF) relaying scheme and then transmits it to the indoor component. The indoor component then converts the received electrical signal into an optical signal by using a light-emitting diode. A legitimate receiver (i.e., Bob) deployed on the floor receives the optical signal. An eavesdropper (i.e., Eve) deployed in the RF or VLC link wiretaps the confidential information. In this study, we use the secrecy outage probability (SOP) and the probability of strictly positive secrecy capacity (SPSC) to evaluate the system performance. We then obtain the closed-form expression for a lower bound on the SOP and an exact closed-form expression for the probability of SPSC when the RF and VLC links are wiretapped, respectively. Numerical results are presented to validate the accuracy of our derivations. We further discuss the effects of the noise standard deviation, the equivalent threshold of the signal-to-noise ratio, and the floor radius on the system secrecy performance when the VLC link is eavesdropped upon. For the case when the RF link is eavesdropped upon, the impacts of the distance between Alice and the relay, the path loss exponent, the fading factor, and the distance between Alice and Eve on secrecy performance are also provided.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mahmoud M.A. Eid ◽  
Eslam Shehata ◽  
Ahmed Nabih Zaki Rashed

Abstract This paper contains a main model which concludes a two optical fiber cable along 70 km and with Parametric/Raman amplifiers with a result of total power 0.781 dBm that computed by the optical power meter which is located before the receiver part and the second optical fiber channel, a total power −44.186 dBm at the end of model which is computed by the electrical power meter visualizer, and a max. Q factor 2.548 computed by the BER analyzer. The suggested model has outlined some updates on the previous model to improve the results so that the results are increased at the same length as the following: total power of optical signal becomes 10.039 dBm, total power of electrical signal becomes 0.624 dBm, and the max. Q factor becomes 9.60787.


2021 ◽  
Vol 32 ◽  
Author(s):  
Binh Pham Thanh ◽  
Thuy Van Nguyen ◽  
Van Hoi Pham ◽  
Huy Bui ◽  
Thi Hong Cam Hoang ◽  
...  

In this paper, we report a new type of refractometer based on a D-shaped fiber Bragg grating (FBG) integrated in a loop-mirror optical fiber laser. This proposed sensor is used in wavelength interrogation method, in which the D-shaped FBG is applied as a refractive index (RI) sensing probe and a mirror to select mode of laser. The D-shaped FBG is prepared by the removal of a portion of the fiber cladding covering the FBG by means of side-polishing technique. The D-shaped FBG sensing probe integrated in a loop-mirror optical fiber laser with saturated pump technique, the characteristics of sensing signals have been improved to obtain stable intensity, narrower bandwidth and higher optical signal-to-noise ratio compare to normal reflection configuration. The limit of detection (LOD) of this sensor can be achieved to 2.95 x 10-4 RIU in the refractive index (RI) range of 1.42-1.44. Accordingly, we believe that the proposed refractometer has a huge potential for applications in biochemical-sensing technique.


2021 ◽  
Vol 16 (2) ◽  
pp. 188-195
Author(s):  
Keyuan Liu ◽  
Haibin Li ◽  
Ya Wang

The weak direct current (DC) signals detected and converted by the photodetector are output to the mobile phone by voltage/frequency switching, and the signals are processed by the mobile phone APP and audio conversion module. The photodetector is equipped with the automatic switching function to design an optical power meter and detect weak signals. Meanwhile, the optical cable identification system is analyzed and combined with the optical power meter to generate an optical fiber sensing network to improve the weak alternating current (AC) signal detection. This network needs data fusion in sensor nodes’ data collection. The cluster routing protocol is introduced and combined with the back propagation neural network (BPNN) to propose a method suitable for this photoelectric transmission and improve the information fusion and accuracy. In the experiment, the optical power meter is output in gears first, and the output waveforms are normal. The photodiode’s optical power is adjusted to obtain different frequencies on the oscilloscope. In the proposed optical fiber sensing network, weak AC signals are amplified significantly, and different optical fiber lines can be distinguished in the optical cables. The proposed information collection method can reduce network communication and node energy consumption.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
R. A. Perez-Herrera ◽  
M. Bravo ◽  
P. Roldan-Varona ◽  
D. Leandro ◽  
L. Rodriguez-Cobo ◽  
...  

AbstractIn this work, an experimental analysis of the performance of different types of quasi-randomly distributed reflectors inscribed into a single-mode fiber as a sensing mirror is presented. These artificially-controlled backscattering fiber reflectors are used in short linear cavity fiber lasers. In particular, laser emission and sensor application features are analyzed when employing optical tapered fibers, micro-drilled optical fibers and 50 μm-waist or 100 μm-waist micro-drilled tapered fibers (MDTF). Single-wavelength laser with an output power level of about 8.2 dBm and an optical signal-to-noise ratio of 45 dB were measured when employing a 50 μm-waist micro-drilled tapered optical fiber. The achieved temperature sensitivities were similar to those of FBGs; however, the strain sensitivity improved more than one order of magnitude in comparison with FBG sensors, attaining slope sensitivities as good as 18.1 pm/με when using a 50 μm-waist MDTF as distributed reflector.


2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Herryawan Pujiharsono ◽  
Duwi Utami ◽  
Rafina Destiarti Ainul

Wireless network technology that is used today is developing rapidly because of the increasing need for location information of an object with high accuracy. Global Positioning System (GPS) is a technology to estimate the current location. Unfortunately, GPS has a disadvantage of low accuracy of 10 meters when used indoors. Therefore, it began to be developed with the concept of an indoor positioning system. This is a technology used to estimate the location of objects in a building by utilizing WSN (Wireless Sensor Network). The purpose of this study is to estimate the location of the unknown nodes in the lecturer room as an object and obtain the accuracy of the system being tested. The positioning process is based on the received signal strength (RSSI) on the unknown node using the ZigBee module. The trilateration method is used to estimate unknown node located at the observation area based on the signal strength received at the time of testing. The result shows that the path loss coefficient value at the observation area is 0.9836 and the Mean Square Error of the test is 1.251 meters, which indicates that the system can be a solution to the indoor GPS problem.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Parvin Kumar ◽  
Sanjay Kumar Sharma ◽  
Shelly Singla ◽  
Varun Gupta ◽  
Abhishek Sharma

Abstract In today’s scenario, wireless communication is turning into a decisive and leading backbone to access the worldwide network. Therefore, the usage of mobile phones and broadband is rising staggeringly. To satisfy their expulsive needs, it demands increment in data rates while providing higher bandwidth and utilizing optical fiber in wireless communication, and this becomes a worldwide analysis area. Radio over fiber (RoF) system is taken into account as best solution to fulfill these needs. In RoF system, the radio frequency signal operated at millimeter wave (30–300 GHz) is centralized and processed at control station (CS) and also, the CS upconverts this electrical signal to optical domain. By employing optical fiber link, this signal reaches to base station (BS). Then, the received optical signal converts back to electrical domain at the respective BS. Now BS radiates the electrical signal to corresponding mobile station (MS) in commission with the millimeter wave frequency bands. This RoF system is providing massive bandwidth, facilitating large mobility for RF frequency signals, small loss, fast and cost effective setup, wonderful security, and unlicensed spectrum etc. The RoF system introduces microcells structure for BS cells to boost the frequency reuse and needed capacity. It has benefits in terms of ability to fulfill increasing bandwidth demands to cut back the power consumption and the dimensions of the handset devices. This paper firstly explains the overview of existing wireless mobile communication and broadband systems and then, targets the review of RoF system which will become energy efficient system for next generation mobile communication and future broadband systems. This paper also includes the performance degradation and evaluation parameters. Finally, this paper presents the various research opportunities for its implementation zone.


Author(s):  
Theofilos Chrysikos ◽  
Stavros Kotsopoulos ◽  
Eduard Babulak

The aim of this chapter is to summarize and present recent findings in the field of wireless channel modeling that provide a new method for the reliable calculation of the statistical parameters of large-scale variations of the average received signal (shadow fading). This algorithm is theoretically based on a path loss estimation model that incorporates losses due to walls and floors. This has been confirmed to be the most precise mathematical tool for average signal strength prediction for various frequencies of interest and propagation environments. The total path loss is estimated as a sum of two independent attenuation processes: free space loss and losses due to obstacles. This solution allows for a direct and reliable calculation of the deviation of the fluctuations of the average received signal in an obstacle-dense environment.


Author(s):  
Kaveh Pahlavan ◽  
Yunxing Ye ◽  
Ruijun Fu ◽  
Umair Khan

In this invited paper, the authors introduce an overview of the fundamentals of radio frequency (RF) channel measurement and modeling techniques needed for localization inside the human body. To address these fundamentals, the authors use capsule endoscopy as an example application. The authors first provide the results of the Cramer Rao Lower Bound (CRLB) for received signal strength (RSS) based endoscopy capsule localization, inside the human body, using existing path-loss models for radio propagation. Then challenges demanding further research are highlighted for attaining more precise localization using the time-of-arrival (TOA) based ranging techniques.


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