Design of Multi-User Noncoherent Massive SIMO Systems for Scalable URLLC.

Area of Science:

• Wireless Communication Systems
• Signal Processing
• Information Theory

Background:

• Beyond-5G (B5G) and 6G systems require scalable ultra-reliable low-latency communications (sURLLC).
• Massive Single-Input Multiple-Output (SIMO) systems offer diversity gain for high reliability.
• Traditional channel estimation introduces significant overhead and latency.

Purpose of the Study:

• To develop and optimize a non-orthogonal and noncoherent multi-user massive SIMO framework for sURLLC.
• To leverage massive antenna arrays for ultra-high reliability.
• To reduce latency and overhead by employing noncoherent communication techniques.

Main Methods:

• Advocating noncoherent communication, which relies on large-scale fading coefficients instead of instantaneous channel state information (CSI).
• Devising a new differential modulation scheme for non-orthogonal channel access in massive SIMO systems.
• Proposing a max-min Kullback-Leibler (KL) divergence-based design for joint optimization of transmitted powers and sub-constellation assignments.

Main Results:

• The proposed non-orthogonal, noncoherent massive SIMO framework enables scalable sURLLC.
• The differential modulation scheme ensures unique signal determination for multiple users.
• The max-min KL divergence design significantly improves error performance compared to max-min Euclidean distance and conventional coherent ZF receivers.

Conclusions:

• The developed framework effectively supports sURLLC in future wireless systems.
• Noncoherent communication and optimized power/constellation design are crucial for enhancing performance and scalability.
• The proposed approach offers superior error performance, especially for cell-edge users.