UWB ( Ultra Wideband ) is a wireless engineering which uses really low power for communications in a high information rates ( could be 480 Mbps ) over a broad bandwidth in a short distance ( less than 10 metres ) . UWB is the ideal solution for radio streaming multimedia at place or office environment and in a personal country webs PAN, besides it can be used in radio detection and rangings.
UWB system is defined by the Federal Communications Commission ( FCC ) as any wireless system that has a bandwidth larger than 20 % of its Centre frequence, or has a bandwidth equal to or larger than 500 MHz. FCC besides allocates the unaccredited frequence set between 3.1 and 10.6 GHz ( 7.5 GHz ) for UWB radio communicating indoor systems. The maximal allowable power spectral denseness ( psd ) for UWB transmittal is -41.3 dBm/MHz. This means about 0.5mW of mean transmit power when the full 3.1-10.6 GHz set is used.
UWB has many advantages over the traditional narrowband communicating systems as follow:
The major advantage is the channel capacity betterment. Harmonizing to Shannon ‘s capacity bound equation shown below, channel capacity increases linearly with the bandwidth while it increases exponentially with the signal power. Because of that UWB is capable on conveying high informations rates with utilizing low power.
Ben Manny & A ; Kevin Kahn. Ultra-Wide-Band / a Disruptive RF Technology? Spring’02 Intel Developer Forum Conference.
As it is shown, UWB is effectual in the short scope of up to 10 metres.
Another advantage is UWB may be has besides lower cost architectures than narrow set wirelesss. Narrow set architectures use high quality oscillators and tuned circuits to modulate and de-modulate information. UWB senders, nevertheless, can straight modulate a baseband signal cut downing some constituents. On the other manus, UWB receiving systems may necessitate more complex architectures but it can take advantage of digital signal processing techniques. Implementing digital signal processing techniques with the same low cost CMOS processes used for microprocessors will enable radio solutions that scale in cost/performance with digital engineering.
Besides, UWB is robust for melting and intervention. The wide-band nature of UWB reduces the effects of random clip changing amplitude fluctuations. Besides, multipath constituents can be resolved and used to better signal response with UWB engineering. UWB besides promises more robust unsusceptibility to co-channel intervention and narrowband jammers.
Radio over Fibre utilizing UWB
In general, Radio over Fibre ( RoF ) refers to a engineering whereby visible radiation is modulated by any radio signal and transmitted over an optical fiber nexus and transmitted once more as a wireless signal. The term RoF is normally applied when a wireless entree is required.
In RoF systems, wireless signals are transported in optical signifier between a cardinal station and a set of base Stationss, after that it will be radiated with the needful radio technique. Each base station can pass on over a wireless nexus with the nomadic Stationss located within the wireless scope of this base station.
In UWB wireless over fiber, there is a disputing job of low-cost and high public presentation transition of high informations rates modulated communicating signals from optical manner ( over individual manner and multimode fiber ) to radio frequence manner and vice-versa.
UWB over Fibre Architecture
There is much possible architectures to be adopted but the chief thought is to link two or more UWB nodes together with optical fiber. Each node has to hold optical to electrical convertor ( O/E ) and electrical to optical convertor ( E/O ) . Each node ( Access Point ) transmits and receives UWB signals to the user ‘s device located at the scope of the node. Figure below simplified this construct.
Fig 2 – UWB over fibre architecture
Moshe Ran, Yossef Ben Ezra, Motti Haridim, and Boris. I. Lembrikov, Holon Institute of Technology ( H.I.T ) , Ultra Wideband Radio over Optical Fibre
Purposes and aims
The purpose from this thesis is to analyze the possibility of linking UWB user to a far UWB base station utilizing another high bandwidth technique to maintain the benefit of UWB high information rates.
The most effectual method is to utilize the high bandwidth optical fiber and implement a wireless over fiber to accomplish high velocities. Figure below illustrates the block diagram of this thought. The consequences of the SNR and the BER will demo us the possible lengths of the optical fiber which could be used to accomplish this mark.
UWB Base station
UWB Access Point
Fig 3 – Optical over Fibre utilizing UWB diagram
The aims will be
Background analyzing for UWB ( Ultra WideBand ) technique.
Background analyzing for optical fiber.
Background analyzing for Radio over Fibre.
Planing and execution for a MatLab codification for Optical over Fibre utilizing UWB.
Analyse the consequences of the system public presentation.
Writing a whole study about this topic.
1 ) Moshe Ran, Yossef Ben-Ezra, and Boris Lembrikov H.I.T – Holon Institute of Technology, “ Ultra-Wideband Radio-over-optical Fiber: engineerings and applications ”
This paper investigates the constructs, engineerings and applications of Ultra-Wideband Radio over optical fiber ( UROOF ) and provides overview of cardinal consequences of the funded undertaking UROOF. They studied the theoretical facets of the UROOF channel, and show by experimentation, cardinal characteristics of this new engineering, through a proof platform. UROOF envision that within 3-5 old ages, fiber optics will be widely spread for indoor residential applications, and the tendency of utilizing multimode fibers ( MMF ) for in-building small-office-home office ( SOHO ) will increase. The cardinal drivers will be services that are required by the users: distribution of several watercourses of High Definition Television, rich multimedia content, genuinely broadband connexion to the substructure etc. Hence the great chance for UROOF engineering for scope extension applications will be available over the “ in-house fiber substructure ” . For this application scenario, WPAN, W-USB devices, Bluetooth 3.0 will be the natural surrounding that is embedded in users devices. As the paper say, UROOF will supply alone engineering to enable the scope extension of these inherently limited engineerings.
2 ) Zoubir Irahhauten, Homayoun Nikookar, and Gerard J. M. Janssen, “ An Overview of Ultra Wide Band Indoor Channel Measurements and Modelling ”
In this missive, an overview of reported measurings and modeling of the extremist broad set ( UWB ) indoor wireless channel is presented. An debut to UWB engineering and UWB channels is provided. Different UWB channel sounding techniques are discussed and attacks for the modeling of the UWB channel are reviewed. The available indoor UWB channel measuring consequences are consulted and consequently, the major UWB channel parametric quantities are presented and compared to those of narrowband systems. The freshness of this work is the assemblage of different UWB channel parametric quantities, analysis, and comparing. Added with the influence of UWB aerial in channel-modelling, every bit good as the frequency-dependency of the channel parametric quantities, leads to a decision on the UWB wireless channel modeling.
3 ) Jianping Yao, Senior Member, IEEE, Member, OSA, Fei Zeng, Member, IEEE, and Qing Wang, “ Photonic Coevals of Ultra wideband Signals ”
In this paper, techniques to bring forth UWB pulsations in the optical sphere have been discussed. These techniques were divided into three classs: 1 ) PM-IM transition in a diffusing device, 2 ) microwave filtrating utilizing a photonic microwave delay-line filter holding two- or three lights-outs with one negative pat, and 3 ) optical spectral defining and frequency-to-time function in a diffusing device. The cardinal characteristic of the techniques in all the three classs is that all could be implemented utilizing all fiber-optic constituents, which provide the potency for integrating utilizing integrated photonic circuits. Compared to the techniques in the 2nd and 3rd classs, the techniques in the first class have a simpler construction, with merely a individual LD required. The attack based on spectral defining and frequency-to-time function in the 3rd class has more flexibleness in bring forthing UWB pulsations with arbitrary forms. The usage of an optical pulsed beginning may do the system more complicated and dearly-won.
4 ) Joao Nascimento and Homayoun Nikookar ( Senior Member IEEE ) , International Research Centre for Telecommunications and Radar ( IRCTR ) , Department of Electrical Engineering, Mathematics and Computer Science, Delft University of Technology, “ On the Range-Data Rate Performance of Outdoor UWB Communication ”
Major envisioned commercial Ultra Wideband ( UWB ) applications are indoor. However, the suitableness of UWB engineering for informations communicating over longer scopes may besides hold a relevant function in the outdoor radio communications. In this paper it is demonstrated that fulfilling the FCC out-of-door emanation bounds, IR-UWB is a suited engineering for long scope communicating at low informations rates utilizing the PAM and PPM transitions. In the AWGN channel, better public presentations are obtained with the usage of higher order degrees of PPM transition comparing with the best public presentation obtained utilizing binary PAM. Consequently, for the limited power system, longer scopes can be achieved for the UWB nexus with the usage of PPM transition when compared to PAM transition. Sing out-of-door shadowing environments with signal fluctuations present at the receiving system, lower range-data rate public presentation is obtained for the UWB nexus when compared to the free infinite environment.
The immense bandwidth of UWB technique influences signal extension. The UWB frequence dependence of two different stuffs utilized for the land contemplation, which are frequently used in out-of-door environments, is incorporated in the two-ray way loss theoretical account. Using the UWB frequence dependent way loss theoretical account, for the most considered distances there is a little betterment in the accomplishable range-data rate public presentation of the UWB nexus, when compared to the instance of no land contemplation.
For different BER and outage chances, tabular arraies of accomplishable range-data rate public presentation of the UWB nexus for the free infinite, lognormal tailing and the frequence dependent two-ray way loss theoretical accounts are provided. Consequences of this survey can be used in the design of out-of-door UWB systems every bit good as in the analysis of range-data rate trade off of the UWB communicating systems.
Experimental/investigative methods to be adopted
In this undertaking, Matlab codification could be used to imitate the system and from the needed consequences, we could analyze the public presentation.
We will imitate the system with 2 parts, wireless portion with UWB technique and optical fiber portion. The codification should incorporate the matching between the two parts. In this simulation we will analyze the SNR and BER for several UWB distances and several optical fiber lengths.
The consequences will give us an thought about the possible fibre lengths could be used for Optical over Fibre utilizing UWB.
Dissertation work should be finished in 16 hebdomads. The work could be divided into 7 activities from A to G. The activities and their periods are as follows:
A. Background analyzing for UWB ( Ultra WideBand ) technique. ( 2 hebdomads )
B. Background analyzing for optical fiber. ( 2 hebdomads )
C. Background analyzing for Radio over Fibre. ( 2 hebdomads )
D. Designing and execution for a MatLab codification for Optical over Fibre utilizing UWB. ( 4 hebdomads including convergence )
E. Analyse the consequences of the system public presentation. ( 4 hebdomads including convergence )
F. Writing a whole study about this topic. ( 9 hebdomads including convergence )
G. Review and concluding checking for the analysing and overall study. ( 2 hebdomads )
The overall activities can be more illustrated with its overlapping utilizing the undermentioned Gantt chart:
Fig 4 – Gantt chart for the thesis activities
Deliverables or specific results
From the consequences of the matlab codification, the SNR and the BER, we should acquire the possible fibre lengths to convey UWB signal over it.