Set Size Bound for Aperiodic Z-Complementary Sets
Cheng-Yu Pai, Yu-Che Tung, Zhen-Ming Huang, Chao-Yu Chen
TL;DR
The paper resolves a long-standing conjecture on the set-size upper bound for aperiodic Z-complementary sets by proving $M\le\left\lfloor\dfrac{NL}{Z}\right\rfloor$ using a Welch-bound framework. It also introduces an algebraic construction of ZCSs based on extended generalized Boolean functions (EGBFs) that achieve this bound with new parameter regimes, yielding optimal ZCSs such as $(6,4,6,4)$ and $(9,4,9,4)$. This work clarifies the limits of ZCS size, demonstrates the bound's tightness, and expands design possibilities for ZCS-based applications. The results advance sequence design for multi-carrier systems and other areas requiring low aperiodic cross-correlation within a specified zero-correlation zone.
Abstract
The widely and commonly adopted upper bound on the set size of aperiodic Z-complementary sets (ZCSs) in the literature has been a conjecture. In this letter, we provide detailed derivations for this conjectured bound. A ZCS is optimal when its set size reaches the upper bound. Furthermore, we propose a new construction of ZCSs based on extended generalized Boolean functions (EGBFs). The proposed method introduces optimal ZCSs with new parameters.
