2 research outputs found
SCMA for Open-Loop Joint Transmission CoMP
Sparse Code Multiple Access (SCMA), a non-orthogonal multiple access scheme,
has been introduced as a key 5G technology to improve spectral efficiency. In
this work, we propose SCMA to enable open-loop coordinated multipoint (CoMP)
joint transmission (JT). The scheme combines CoMP techniques with multi-user
SCMA (MU-SCMA) in downlink. This scheme provides open-loop user multiplexing
and JT in power and code domains, with robustness to mobility and low overhead
of channel state information (CSI) acquisition. The combined scheme is called
MU-SCMA-CoMP, in which SCMA layers and transmit power of multiple transmit
points (TPs) are shared among multiple users while a user may receive multiple
SCMA layers from multiple TPs within a CoMP cluster. The benefits of the
proposed scheme includes: i) drastic overhead reduction of CSI acquisition, ii)
significant increase in throughput and coverage, and iii) robustness to channel
aging. Various algorithms of MU-SCMA-CoMP are presented, including the
detection strategy, power sharing optimization, and scheduling. System level
evaluation shows that the proposed schemes provide significant throughput and
coverage gains over OFDMA for both pedestrian and vehicular users