TY - GEN
T1 - On joint modulation design in two-user non-orthogonal multiple access channels
AU - Ng, Benjamin K.
AU - Lam, Chan Tong
N1 - Publisher Copyright:
© 2016 IEEE.
PY - 2016/10/19
Y1 - 2016/10/19
N2 - In this paper, we consider the joint signal optimization in two-user non-orthogonal multiple access (NOMA) channels with finite-alphabet constellations. In the proposed design, the constellation of the second user is optimally rotated with the assumption that joint maximum-likelihood detection is employed at the receiver. With M antennas at the receiver, closed-form expressions for the optimal angles as a function of M, the channel conditions and the users' power levels are derived for 4-QAM constellation. Using rotated constellation, the performance of NOMA in terms of bit-error-rate is shown to be improved. The proposed approach is applicable in the uplink NOMA where users share the same time/frequency channel or in the downlink NOMA where users are multiplexed in the power domain.
AB - In this paper, we consider the joint signal optimization in two-user non-orthogonal multiple access (NOMA) channels with finite-alphabet constellations. In the proposed design, the constellation of the second user is optimally rotated with the assumption that joint maximum-likelihood detection is employed at the receiver. With M antennas at the receiver, closed-form expressions for the optimal angles as a function of M, the channel conditions and the users' power levels are derived for 4-QAM constellation. Using rotated constellation, the performance of NOMA in terms of bit-error-rate is shown to be improved. The proposed approach is applicable in the uplink NOMA where users share the same time/frequency channel or in the downlink NOMA where users are multiplexed in the power domain.
KW - modulation
KW - non-orthogonal multiple access
UR - http://www.scopus.com/inward/record.url?scp=84994234538&partnerID=8YFLogxK
U2 - 10.1109/ISWCS.2016.7600876
DO - 10.1109/ISWCS.2016.7600876
M3 - Conference contribution
AN - SCOPUS:84994234538
T3 - Proceedings of the International Symposium on Wireless Communication Systems
SP - 65
EP - 69
BT - ISWCS 2016 - 13th International Symposium on Wireless Communication Systems, Proceedings
PB - VDE Verlag GmbH
T2 - 13th International Symposium on Wireless Communication Systems, ISWCS 2016
Y2 - 20 September 2016 through 23 September 2016
ER -