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- 저자 : ( Walid A. Hassan ) (검색결과 4 건)
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A Spectrum Sharing Model for Compatibility between IMT-Advanced and Digital Broadcasting
( Walid A. Hassan ),( Tharek Abd Rahman ) 한국인터넷정보학회 2012 KSII Transactions on Internet and Information Syst Vol.6 No.9
Recently, the International Telecommunication Union allocated the 470-862 MHz band to the digital broadcasting (DB) service. Moreover, the 790-862 MHz sub-band will be allocated to the next-generation mobile system, known as the International Mobile Telecommunication - Advanced (IMT-A), and to the DB on a co-primary basis in the year 2015. Currently, two candidate technologies are available to represent the IMT-A system; the Mobile WiMAX and Long Term Evolution - Advanced (LTE-A). One of the main criteria of the IMT-A candidate is to not cause additional interference to the primary service (i.e., DB). In this paper, we address the spectrum sharing issue between the IMT-A candidates and the DB service. More precisely, we investigate the interference effect between the DB service and the mobile network, which could be either LTE-A or WiMAX. Our study proposes a spectrum sharing model to take into account the impact of interference and evaluates the spectrum sharing requirements such as frequency separation and separation distance. This model considers three spectrum sharing scenarios: co-channel, zero guard band, and adjacent channel. A statistical analysis is performed, by considering the interferer spectrum emission mask and victim receiver blocking techniques. The interference-to-noise ratio is used as an essential spectrum sharing criterion between the systems. The model considers the random distribution of the users, antenna heights, and the bandwidth effect as well as the deployment environment in order to achieve spectrum sharing. The results show that LTE-A is preferable to WiMAX in terms of having less interference impact on DB; this can eventually allow the operation of both services without performance degradation and thus will lead to efficient utilization of the radio spectrum.
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Walid A Hassan,Han Shin Jo,Tharek Abd Rahman 한국산학기술학회 2013 SmartCR Vol.3 No.5
The switch from analog to digital television broadcasting (DB) has freed up a newly available spectrum called the digital dividend (DD) band. This band is expected to be used for both International Mobile Telecommunication-Advanced (IMT-A) and terrestrial DB, which could lead to performance degradation for both services. In this study, a simulation model is proposed to identify the requirements for coexistence between the new system (i.e., IMT-A) and the primary system (i.e., DB) in the DD band. Our model evaluates the compatibility between the two services by considering a feasible spectrum allocation: (i) the frequency plan for DB recommended by the International Telecommunication Union (ITU) in 2006 and (ii) the European preferred harmonized spectrum for mobile channel assignment proposed in 2009. Using the Monte Carlo method, we quantify the minimum distance between the systems to ensure reliable services for a given frequency guard band. We also propose a practical guideline for efficient spectrum sharing, which will increase the efficiency of DD spectrum usage between administrations. Unlike the previous studies where the services can coexist in all adjacent channels, our results show that coexistence is possible for a limited number of adjacent channels and for a specific sharing scenario.
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( Walid A. Hassan ),( Han Shin Jo ),( Maziar Nekovee ),( Chee Yen Leow ),( Tharek Abd Rahman ) 한국인터넷정보학회 2012 KSII Transactions on Internet and Information Syst Vol.6 No.8
This paper proposes a system called Wireless Link based on Global Communication Channel (WLGCC) to enhance the spectrum sharing between digital broadcasting (DB) services and the cognitive radio (CR) system in the licensed band of 470-790 MHz. The WLGCC aims to enhance the spectrum sensing and geolocation database (GLD) spectrum sharing methods in the CR system. Spectrum sensing can be enhanced by receiving the status of the used frequencies from the WLGCC, thereby eliminating the need for a low detection threshold (i.e., avoiding the hidden node problem). In addition, the GLD can be enhanced by providing a reliable communication link between the database and the CR device in the form of an unused TV white space that is reserved as the proposed Global Communication Channel (GCC). This paper analyzes the coexistence of the new WLGCC system and the DB service in terms of avoiding additional interference. Specifically, we mathematically determine the WLGCC parameters, such as the in-band and out-of-band power levels, and operation coverage, and verify them using Monte Carlo simulation. The results show that WLGCC does not degrade the existing DB service and reliably transmits information of the vacant (or used) frequency bands to the CR.
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