• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.11A
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• pp.815-821
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• 2009

In this paper, we propose a new type of mutually cooperative relaying (MCR) scheme based on a spatially coordinate-interleaved orthogonal design (SCID), in which two cooperative users are spatially multiplexed without bandwidth expansion. It provides not only diversity gain (with order of two) as in the existing MCR scheme, but also additional coding gain. Our simulation results demonstrate that the proposed SCID scheme is useful for improving the uplink performance as long as one user can find another active user as a close neighbor that is simultaneously communicating with the same destination, e.g., a base station in the cellular network.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.3
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• pp.172-179
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• 2013

In this paper, we consider network-coded bi-directional relaying (NCBR) schemes over an asymmetric channel, in which bi-directional links have the different channel quality, as well as the asymmetric traffic load. In order to deal with asymmetric nature, two different types of NCBR schemes are considered: network coding after padding (NaP) and network coding after fragmentation (NaF). Even if NaP has been known as only a useful means of dealing with the asymmetry in traffic load up to now, our analysis shows that its gain can be significantly lost by the asymmetry in channel quality, under the given bit error performance constraint. Furthermore, it is shown that NaF always outperforms NaP, as well as traditional bi-directional relaying scheme.