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A transmission capacity enhancement of the CDM‐based satellite DMB system
Author(s) -
Lee HoJin,
Lee InKi,
Chang DaeIg,
Kim TaeHoon
Publication year - 2008
Publication title -
international journal of satellite communications and networking
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.388
H-Index - 39
eISSN - 1542-0981
pISSN - 1542-0973
DOI - 10.1002/sat.909
Subject(s) - computer science , computer network , channel (broadcasting) , degradation (telecommunications) , multipath propagation , link adaptation , telecommunications , fading
After the launch of Satellite Digital Multimedia Broadcasting (S‐DMB) service in Korea, there was a requirement to have more channels to accommodate more bandwidth‐requiring applications. We designed a new architecture to provide the system with more channel capacity while maintaining the current performance as much as possible. We took a hierarchical modulation technology used for the DVB‐S2 standard. A number of combinations of modulation parameters and FEC modes have been simulated for the evaluation of technical feasibility of the proposed structure. Also investigations were carried out to assess the impact to current service performance. It was found that a 16200‐bit LDPC with hierarchical modulation could give additional channel capacity while keeping the current quality of service for selected CODEC and code rates (Int. J. Satellite Commun. Networks 2004; 22). Though 1ldB degradation of BER to the existing service was resulted by this approach, but no perceptional service degradation was expected since current link margin is larger than 3ldB. We found that about 36% of capacity enhancement can be achievable by the hierarchical modulation with proper CODEC selection. Additional degradation, however, may be encountered in mobile environment due to the multipath channel in spite of its performance immunity to the Doppler effect. Copyright © 2008 John Wiley & Sons, Ltd.