average power ratio‚ orthogonality of the signals of different users even for transmission over a time dispersive channel. It is of low complexity for user separation and channel equalization that doesn’t require any channel state information at the transmitter. It combines the advantages of both CDMA and OFDMA. I. INTRODUCTION Currently‚ research on beyond 3rd and 4th generation (B3G/4G) mobile radio systems is in progress worldwide. A future mobile radio system
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International Journal of Computer and Electrical Engineering‚ Vol.4‚ No.2‚ April 2012 Wireless Transmission of Electrical Power Overview of Recent Research & Development Sagolsem Kripachariya Singh‚ T. S. Hasarmani‚ and R. M. Holmukhe wireless transmission at 1891 in his “experimental station” at Colorado. Nikola Tesla successfully lighted a small incandescent lamp by means of a resonant circuit grounded on one end. A coil outside laboratory with the lower end connected to the ground
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data. All modules in the communication system are expected to be designed and implemented using VHDL programming language. The software to be used is Xilinx. Index Terms—OFDM System‚ Cyclic prefixing‚ Block diagram of the OFDM system. Transmitter section of an OFDM information wireless‚ quickly and accurately. To address this need‚ communications engineer have combined technologies suitable for high rate transmission with forward error correction (FEC) techniques. This is particularly
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CONCEPT OF WIRELESS ELECTRICITY (Wi-Tricity) Our forefathers marveled at the invention of glowing light bulbs by Thomas Edison in 1879. However‚ to us 21st centurions‚ the light bulb is nothing out of the ordinary. When computers‚ cell phones‚ laptops‚ iPods‚ etc. were invented our antennas tweaked. Now this is what you call invention! However‚ as time’s progressing we are getting used to these devices. In fact‚ charging all these appliances has become so very cumbersome. Each appliance has its
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measurements to celestial bodies like sun and stars to calculate their location. The 1920s witnessed the introduction of more advanced technique-radio navigation-based at first on radios that allowed navigators to locate the direction of shore-based transmitters when in range. Later development of artificial satellites made possible the transmission of more precise‚ line of sight radio navigation signals and sparked a new era in navigation technology. Satellites are first used in position finding in a
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CHAPTER 2 MULTIPLE ACCESS A limited amount of bandwidth is allocated for wireless services. A wireless system is required to accommodate as many users as possible by effectively sharing the limited bandwidth. Therefore‚ in the field of communications‚ the term multiple access could be defined as a means of allowing multiple users to simultaneously share the finite bandwidth with least possible degradation in the performance of the system. There are several techniques how multiple accessing can
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another is called transmission or communication media. There are two categories of transmission media used in computer communications. Infrared Infrared transmission is usually limited to a small area‚ e.g. one room‚ with the transmitter pointed towards the receiver. The hardware is inexpensive and does not require an antenna. Radio A network that uses electromagnetic radio waves operates at radio frequency and its transmissions are called RF
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transmission‚ optical fibers have largely replaced copper wire communications in core networks in the developed world. The process of communicating using fiber-optics involves the following basic steps: Creating the optical signal involving the use of a transmitter‚ relaying the signal along the fiber‚ ensuring that the signal does not become too distorted or weak‚ receiving the optical signal‚ and converting it into an electrical Application Optical fiber is used by many telecommunications
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BOOK REVIEW IN COMMUNICATIONS CHAPTER 2 # Electronic Communications System By Wayne Tomasi SIGNAL ANALYSIS AND MIXING DEFINITIONS TERMS 1) Electrical signals of which amplitude changes continuously with respect to time with no breaks or discontinuities. Analog Signals 2) Electrical signals that are described as discrete; their amplitude maintains constant level for a prescribed period of time and then it changes to another level with respect to time with no breaks
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ConstruCtion microcontroller-based Ultrasonic distance meter and receiver)‚ current buffer ULN2003‚ operational amplifier LM324‚ inverter here are several ways to measCD4049‚ four 7-segment displays‚ five ure distance without contact. transistors and some discreet comOne way is to use ultrasonic ponents. The ultrasonic transmitterwaves at 40 kHz for distance measurereceiver pair is shown in Fig. 1. ment. Ultrasonic transducers measure Ultrasonic generators use piezothe amount of time
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