Optimization of Hierarchical-QAM based Downlink Multiple Access with Statistical CSI
- Resource Type
- Conference
- Authors
- Zhu, Jinkang; Zhou, Shengli; Zhao, Ming
- Source
- 2023 IEEE 24th International Workshop on Signal Processing Advances in Wireless Communications (SPAWC) Signal Processing Advances in Wireless Communications (SPAWC), 2023 IEEE 24th International Workshop on. :291-295 Sep, 2023
- Subject
- Communication, Networking and Broadcast Technologies
Signal Processing and Analysis
Wireless communication
Closed-form solutions
Quadrature amplitude modulation
OFDM
Power control
Signal processing
Downlink
Nonorthogonal multiple access
hierarchical constellation
power control
statistical channel state information
- Language
- ISSN
- 1948-3252
This paper considers a downlink multiple access scenario with OFDM transmissions in frequency selective channels. The users are assigned with different bit streams from hierarchical quadrature amplitude modulation (QAM) rather than assigned with different subcarriers as in orthogonal frequency division multiple access (OFDMA). Based on statistical channel state information in the form of the average signal-to-noise ratios of the users, we derive a closed-form solution on the hierarchical constellation design. The numerical results demonstrate the performance advantage of the proposed system over OFDMA where power control is also applied based on the same channel feedback.