Construction of $J^{\text{th}}$-stage Nonuniform Wavelets on Local Fields

Abstract: Shah and Abdullah [Complex Analysis Operator Theory, 9 (2015), 1589-1608] have introduced a generalized notion of nonuniform multiresolution analysis (NUMRA) on local field $K$ of positive characteristic in which the translation set $\Lambda$ acting on the scaling function to generate the core space $V_{0}$ is no longer a group, but is the union of ${\mathcal Z}$ and a translate of ${\mathcal Z}$, given by $\Lambda=\left{0,u(r)/N \right}+{\mathcal Z}$, where $N \ge 1$ is an integer and $r$ is an odd integer such that $r$ and $N$ are relatively prime, and ${\mathcal Z}={u(n): n\in\mathbb N_{0}}$ is a complete list of distinct cosets of the unit disc $\mathfrak D$ in $K^+.$ In this paper, we focus on the extension of nonuniform continuous wavelets to the construction of $J^{\text{th}}$-stage nonuniform discrete wavelets on local fields. We establish some general characterizations for the $J^{\text{th}}$-stage nonuniform discrete wavelet systems to be orthornormal bases in $L^2(\Lambda)$. Moreover, we establish a relation between the continuous wavelets of $L^2(K)$ and their discrete counterparts of $l^2(\Lambda)$.