A constellation power allocation scheme for two-user Gaussian MAC


Autoria(s): Harshan, J; Rajan, Sundar B
Data(s)

2011

Resumo

Constellation Constrained (CC) capacity regions of two-user Gaussian Multiple Access Channels (GMAC) have been recently reported, wherein introducing appropriate rotation between the constellations of the two users is shown to maximally enlarge the CC capacity region. Such a Non-Orthogonal Multiple Access (NO-MA) method of enlarging the CC capacity region is referred to as Constellation Rotation (CR) scheme. In this paper, we propose a novel NO-MA technique called Constellation Power Allocation (CPA) scheme to enlarge the CC capacity region of two-user GMAC. We show that the CPA scheme offers CC sum capacities equal (at low SNR values) or close (at high SNR values) to those offered by the CR scheme with reduced ML decoding complexity for some QAM constellations. For the CR scheme, code pairs approaching the CC sum capacity are known only for the class of PSK and PAM constellations but not for QAM constellations. In this paper, we design code pairs with the CPA scheme to approach the CC sum capacity for 16-QAM constellations. Further, the CPA scheme used for two-user GMAC with random phase offsets is shown to provide larger CC sum capacities at high SNR values compared to the CR scheme.

Formato

application/pdf

Identificador

http://eprints.iisc.ernet.in/46124/1/Per_Ind_Mob_%20Rad_Com_2050_2011.pdf

Harshan, J and Rajan, Sundar B (2011) A constellation power allocation scheme for two-user Gaussian MAC. In: 2011 IEEE 22nd International Symposium on Personal Indoor and Mobile Radio Communications (PIMRC), 11-14 Sept. 2011, Toronto, ON.

Publicador

IEEE

Relação

http://dx.doi.org/10.1109/PIMRC.2011.6139874

http://eprints.iisc.ernet.in/46124/

Palavras-Chave #Electrical Communication Engineering
Tipo

Conference Paper

PeerReviewed