시공간 선 부호기반 상향링크 비직교 다중접속 시스템

초록

In this paper, we consider an uplink non-orthogonal multiple access (NOMA) with space-time line codes (STLC) where two mobile stations (MSs) send packets simultaneously to a base station (BS) equipped with two antennas. In particular, we propose two techniques in order to improve bit-error-rate (BER) performance at the BS: transmit power control and constellation phase steering. The proposed techniques are validated by extensive computer simulations. It is worth noting that the conventional STLC cannot achieve the optimal diversity order and it deteriorates the BER performance in the uplink NOMA systems. The designed transmit power control-based STLC technique yields a better BER performance compared with the conventional STLC in the uplink NOMA systems, yet it still cannot achieve the optimal diversity order. Interestingly, the proposed phase steering-based STLC technique significantly improves the BER performance as well as achieves the optimal diversity order for the high signal-to-noise ratio regime.

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