On the codebook design for NOMA schemes from bent functions

Executive Summary

This paper proposes a recursive method for designing codebooks for uplink grant-free Non-Orthogonal Multiple Access (NOMA) schemes, utilizing Golay-Davis-Jedwab (GDJ) sequences. The construction aims to achieve massive connectivity with low latency, high energy efficiency, and optimally low coherence, crucial for future wireless communication systems. It details a recursive extension of compatible sets of permutations to generate NOMA codebooks with specific properties.

Why It Matters

This research is relevant for defense analysts as it contributes to the foundational cryptographic and communication technologies that underpin secure and efficient military wireless networks, particularly for massive connectivity and low-latency applications in future battlefield environments. The Naval Postgraduate School's involvement highlights its potential application in defense communication systems.

Key Takeaways

• The paper introduces a recursive construction method for NOMA codebooks using GDJ sequences, designed for massive connectivity with low latency and high energy efficiency.
  Source evidence · PDF page 2

  Uplink grant-free non-orthogonal multiple access (NOMA) is a promising technology for massive connectivity with low latency and high energy efficiency. In code-domain NOMA schemes, the requirements boil down to the design of codebooks that contain a large number of spreading sequences with low peak-to-average power ratio (PAPR) while maintaining low coherence.

• The proposed codebooks achieve optimally low coherence and maintain a low Peak-to-Average Power Ratio (PAPR), which are critical for minimizing interference and improving energy efficiency in wireless systems.
  Source evidence · PDF page 29

  The proposed approach allows for constructing many NOMA codebooks of 6N GDJ sequences of length i n line-eq-IEq866 and the lowest possible coher­ence in l ine-eq-IEq867 for integers i n line-eq-IEq868. Our results complement the work of [15] regarding the construction of NOMA codebooks with large overloading factors, whereas the problem of improving the general upper bound remains open.

• The construction allows for generating NOMA codebooks of significant size (e.g., 6N GDJ sequences of length 2^m) across various dimensions, offering scalability for future communication demands.
  Source evidence · PDF page 32

  The recursive construction generates NOMA codebooks of size i n line-eq-IEq941 for all dimen­sions i n line-eq-IEq942, where each sequence has length i n line-eq-IEq943 and PAPR upper bounded by 2 (Table 10). All codebooks achieve the optimal coherence in l ine-eq-IEq945 as shown in (5), and the construc­tion maintains a constant overloading factor i nline-eq-IEq946 for all dimensions i n line-eq-IEq947 with i n line-eq-IEq948.

Strategic Relevance

The development of efficient and secure NOMA codebooks is strategically important for military communications, enabling robust and high-capacity wireless networks for command and control, intelligence, surveillance, and reconnaissance (ISR) in contested environments. Low PAPR and optimal coherence are vital for stealth and reliability.