Non-Orthogonal Multiple Access with One-Bit Analog-to-Digital Converters Using Threshold Adaptation.

Area of Science:

• Digital Communications
• Signal Processing
• Information Theory

Background:

• High-resolution analog-to-digital converters (ADCs) enable successive interference cancellation for enhanced Gaussian multiple access channel (MAC) capacity.
• One-bit ADCs present significant challenges for digital interference cancellation due to severe signal distortion, limiting MAC capacity gains.

Purpose of the Study:

• To develop an efficient successive interference cancellation and detection scheme for one-bit quantized channels.
• To demonstrate that one-bit channel capacity can be equivalent to interference-free capacity under specific conditions.

Main Methods:

• Proposing an analog-domain interference cancellation approach for one-bit ADCs.
• Analyzing achievable rates by deriving mutual information at each detection stage.
• Developing an optimal transmit power allocation algorithm for fading channels.

Main Results:

• The proposed scheme achieves a sum rate generally outperforming conventional methods.
• An achievable upper bound for the sum rate is demonstrated to be twice that of conventional methods.
• The optimal power allocation algorithm maximizes sum rate in fading channels.

Conclusions:

• The study presents a viable method for interference cancellation in one-bit quantized systems, overcoming limitations of digital processing.
• The proposed scheme offers significant capacity enhancements for Gaussian MACs with one-bit ADCs.
• Analog-domain interference management is shown to be effective for improving communication system performance.