%0 Journal Article
	%A Seung-Jun Yu and  Yeong-Seop Ahn and  Young-Min Ko and  Hyoung-Kyu Song
	%D 2015
	%J International Journal of Electronics and Communication Engineering
	%B World Academy of Science, Engineering and Technology
	%I Open Science Index 104, 2015
	%T Cooperative CDD Scheme Based on Hierarchical Modulation in OFDM System
	%U https://publications.waset.org/pdf/10002293
	%V 104
	%X In order to achieve high data rate and increase the
spectral efficiency, multiple input multiple output (MIMO) system has
been proposed. However, multiple antennas are limited by size and
cost. Therefore, recently developed cooperative diversity scheme,
which profits the transmit diversity only with the existing hardware by
constituting a virtual antenna array, can be a solution. However, most
of the introduced cooperative techniques have a common fault of
decreased transmission rate because the destination should receive the
decodable compositions of symbols from the source and the relay. In
this paper, we propose a cooperative cyclic delay diversity (CDD)
scheme that use hierarchical modulation. This scheme is free from the
rate loss and allows seamless cooperative communication.
	%P 892 - 895