1 research outputs found
General Framework and Novel Transceiver Architecture based on Hybrid Beamforming for NOMA in Massive MIMO Channels
Massive MIMO and non-orthogonal multiple access (NOMA) are crucial methods
for future wireless systems as they provide many advantages over conventional
systems. Power domain NOMA methods are investigated in massive MIMO systems,
whereas there is little work on integration of code domain NOMA and massive
MIMO which is the subject of this study. We propose a general framework
employing user-grouping based hybrid beamforming architecture for mm-wave
massive MIMO systems where NOMA is considered as an intra-group process. It is
shown that classical receivers of sparse code multiple access (SCMA) and
multi-user shared access (MUSA) can be directly adapted. Additionally, a novel
receiver architecture which is an improvement over classical one is proposed
for uplink MUSA. This receiver makes MUSA preferable over SCMA for uplink
transmission with lower complexity. We provide a lower bound on achievable
information rate (AIR) as a performance measure. We show that code domain NOMA
schemes outperform conventional methods with very limited number of radio
frequency (RF) chains where users are spatially close to each other.
Furthermore, we provide an analysis in terms of bit-error rate and AIR under
different code length and overloading scenarios for uplink transmission where
flexible structure of MUSA is exploited.Comment: Partially presented at IEEE ICC 2020 Workshop on NOMA for 5G and
Beyond and to be submitted to IEEE Transactions on Communication