1. Introduction
Periodic systems and structured interactions appear across many scientific and engineering domains. From ancient calendrical systems such as the Chinese sexagenary cycle [
1] to modern sequence design in communications [
2], real-time scheduling in distributed systems [
3], and rhythmic mechanisms of attention in neural processing [
4], modeling and optimizing periodic pairing relationships is a recurring need. Despite this broad relevance, a unified framework for analyzing and designing such systems remains underdeveloped.
Existing approaches to periodic system design have largely evolved within domain-specific silos. In communication theory, complementary sequence pairs [
5] and Zadoff–Chu sequences [
6] provide near-ideal correlation properties for synchronization and channel estimation. In computational scheduling, periodic task allocation strategies [
7] and skip list algorithms [
8] address resource coordination and fast access in dynamic environments. In machine learning, structured sparsity patterns [
9] and periodic connectivity–style designs have been explored for network compression. However, these advances have progressed without a shared theoretical foundation that would enable cross-domain insights and methodological transfer.
The Periodic Pairing Matrix (PPM) model introduced in this paper aims to bridge this gap by providing a unified mathematical framework for modeling and analyzing periodic pairing systems. Our work makes four primary contributions:
First, we establish a rigorous mathematical formulation of periodic pairing systems, deriving fundamental properties including periodicity conditions, coverage theorems, and vacancy patterns. Second, we develop a flexible algorithmic framework that enables system designers to generate customized pairing patterns through parameter selection. Third, we demonstrate the practical utility of our approach through detailed case studies in resource scheduling and neural network design. Fourth, we analyze the computational efficiency and performance characteristics of PPM-based systems, providing guidance for parameter selection and performance optimization.
The remainder of this paper is organized as follows:
Section 2 presents the formal mathematical foundation of the PPM model.
Section 3 describes the general algorithm framework and key computational aspects.
Section 4 details applications in resource scheduling and neural networks.
Section 5 presents experimental results and analysis.
Section 6 discusses broader implications and future directions. Section 7 concludes the paper.
2. Mathematical Foundation
2.1. Basic Definitions and Notation
Let and be two cyclic sequences of lengths and respectively.
Let and be integer stepping parameters that control progression through sequences and .
The pairing position at discrete time
is given by:
2.2. Periodicity Analysis
The system exhibits periodic behavior with period
given by:
Here, lcm denotes the least common multiple, and gcd denotes the greatest common divisor. During this period, the system will traverse all possible pairing states and then return to its initial state.
This period represents the minimum number of steps after which the complete pairing pattern repeats. The derivation follows from number-theoretic properties of modular arithmetic and the Chinese Remainder Theorem [
10].
Based on the above definitions, we can construct a periodic pairing matrix
to record the system state at time t. The matrix has dimensions m × n, and its initial state is denoted by
. At each time step t, the matrix is updated as:
Here is the update function that defines the rule at the pairing position ().
When , all possible pairs are visited exactly once per period.
Given the system of congruences:
this is equivalent to requiring that there exists an integer
such that:
This system has a solution if and only if:
where:
2.3. Vacancy Patterns and Load Balancing
In sub-cycles of length
, the set of visited elements from sequence
is:
The vacancy set is therefore:
The number of vacant positions per sub-cycle is:
We define the load balance metric as:
where
and
are the mean and standard deviation of visit frequencies across all positions.
3. Algorithmic Framework
3.1. Core Algorithm
The complete PPM computation process is formalized in Algorithm 1.
Require: (sequence lengths), (stepping parameters), (initial matrix), (update function), Agg (aggregation function)
Ensure: (result matrix)
1:
2: $M \leftarrow M_0, N_{\text{list}} \leftarrow \left[\right]$)
3: for to do
4:
5:
6:
7:
8:
9: end for
10:
11: return
where is the matrix with 1 at position and 0 elsewhere.
3.2. Computational Complexity
The time complexity of Algorithm 1 is , where is the cost of the update function . The space complexity is for storing the matrix and result history.
For applications requiring real-time performance, we can exploit the periodicity to precompute pairing patterns, reducing the complexity to per step after preprocessing.
3.3. Specialized Variants
3.3.1. Counting Matrix
For simple frequency counting:
3.3.2. Shift Matrix
For cyclic shift operations:
3.3.3. Linear Transform
For linear transformation systems:
3.4. Core Computational Formulas and Notation
Within the periodic allocation matrix framework, several key computational formulas play a central role in characterizing system behavior. This section introduces their definitions and associated notation.
3.4.1. Visit Frequency
For any matrix position
, the number of visits within a complete period is given by
where
is an indicator function that equals 1 if position
is visited during the period and 0 otherwise.
3.4.2. Skip Position Detection
Consider a subcycle of length
Within this subcycle, the set of skipped positions in sequence
is defined as
where
and
denotes the starting time index of the subcycle.
3.4.3. Load Balance Metric
The load balance of the system is quantified by
where Std and Mean denote the standard deviation and mean of all elements in the matrix
respectively.
is a non-zero value.
4. Application Case Studies
4.1. Resource Scheduling in Distributed Computing
We applied the PPM model to a distributed computing scenario with compute nodes and data partitions. The objective was to balance computational load while ensuring periodic access to all data partitions.
As shown in
Table 1, optimal balance is achieved when
and
are coprime (gcd
). The vacancy penalty mechanism (
) significantly improves performance in non-ideal scenarios by artificially distributing load to vacant positions.
4.2. Sparse Neural Network Design
We designed a sparse recurrent neural network using the PPM model with hidden units and time delays. The PPM pattern determined which connections were active at each time step, creating structured sparsity.
Table 2 demonstrates that PPM-based sparsity achieves nearly identical accuracy to full connectivity (93.8% vs. 94.2%) while reducing parameters by 65% and improving training speed by 40%. The structured nature of PPM sparsity also enables more efficient hardware implementation compared to random sparsity patterns.
4.3. Comparative Analysis
We compared the PPM approach against several baseline methods:
Random Pairing: Stochastic pairing with same sparsity level
Round-Robin: Sequential cycling through both dimensions
Prime Modulus: Using prime number properties for coverage
Block Cyclic: Traditional block-cyclic distribution
As shown in
Table 3, the PPM model achieves the optimal combination of coverage, balance, and predictability while maintaining reasonable implementation complexity.
5. Discussion
5.1. Theoretical Implications
5.1.1. Number-Theoretic Foundations
The PPM model realizes core constructs in number theory, particularly modular arithmetic and CRT-style congruence relations [
11]. This connection suggests that additional number-theoretic structures—such as primitive roots or quadratic residues—may be exploited to produce more specialized pairing patterns for systems that require strict coverage guarantees.
5.1.2. Group-Theoretic Interpretation
From a group-theoretic perspective, the PPM mechanism corresponds to an action of on the product group The stepping parameters define a homomorphism that governs subgroup interactions and symmetry, offerinq tools commonly used in alqebraic analysis.
5.1.3. Information Theory and Sequence Design
PPM-generated sequences share properties with deterministic sequences used in communication systems, offering guaranteed coverage and controlled cross-correlation. This aligns with classical sequence design while differing from random sequences used in CDMA or synchronization [
12].Similar periodic-coverage structures also emerge in periodic scheduling frameworks such as PESP in transportation and real-time systems [
13].
5.2. Practical Applications
5.2.1. Wireless Communications and 5G/6G Networks
In contemporary wireless networks, PPM can guide structured resource-block alignment, pilot assignment, and latency-sensitive scheduling. Recent research in massive MIMO shows the need for pilot-allocation strategies that reduce interference and contamination [
14,
15], and even ML-driven pilot-overhead reduction for mm Wave systems [
16]. PPM patterns—with explicit control over vacancy windows—offer deterministic latency and reduced pilot collision risk compared to proportional-fair or round-robin scheduling.
5.2.2. Real-Time and Control Systems
Networked control systems rely heavily on periodic or weakly hard deadlines. Advances in wireless control demonstrate the importance of optimal transmission scheduling for maintaining closed-loop stability under bandwidth constraints [
17]. Meanwhile, weakly hard real-time theory provides a formal basis for understanding periodic deadline violations in control loops [
18]. PPM provides a deterministic pattern template that aligns well with these frameworks, offering predictable worst-case behavior.
5.2.3. Edge Computing and IoT Systems
IoT and edge systems typically involve periodic sensing and energy-constrained communication. Recent surveys show that periodic and quasi-periodic scheduling dominate practical IoT implementations [
19], while predictable link-reliability scheduling is crucial for industrial wireless embedded systems [
20]. PPM’s structured vacancy patterns support predictable low-power modes, improved link utilization, and stable resource-access guarantees.
5.3. Limitations
Dimensionality Constraints: The model’s two-dimensional structure is analytically elegant but less expressive than higher-order tensor or hypergraph representations.
Predictability and Security Concerns: Deterministic scheduling enhances analyzability but may expose predictable patterns, weakening security compared to randomized or cryptographic methods.
Parameter Optimization Complexity: Selecting optimal PPM stepping parameters can require large-scale combinatorial search. Techniques based on number theory or learning-based optimization may mitigate this.
5.4. Future Directions
Adaptive and Learning-Enhanced PPM: Reinforcement learning or Bayesian optimization could tune PPM parameters dynamically, combining determinism with online adaptability.
Higher-Dimensional Extensions: Generalizing PPM to multidimensional periodic systems may broaden applications to multi-resource scheduling and multi-hop networks.
Cross-Domain Applications: Periodic interaction structures appear across biology, economics, and transportation; extending PPM into these domains may both validate and broaden the theoretical framework.
6. Conclusions
We have presented the Periodic Pairing Matrix model as a unified framework for designing and analyzing systems with periodic interaction patterns. The model provides rigorous mathematical foundations, efficient algorithms, and demonstrated practical utility across multiple domains.
Key advantages of the PPM approach include:
Theoretical Foundation: Strong mathematical basis in number theory and modular arithmetic
Flexibility: Tunable parameters enable customized pattern generation
Efficiency: Structured patterns enable computational and memory optimizations
Predictability: Deterministic behavior facilitates system analysis and verification
Experimental results demonstrate that PPM-based systems achieve excellent performance in both resource scheduling (100% utilization in optimal cases) and neural network design (40% training speedup with minimal accuracy loss).
The PPM model opens several promising research directions, including extensions to higher-dimensional systems, adaptive parameter selection, and applications in emerging computing paradigms. We believe this framework provides a valuable tool for researchers and practitioners working with periodic systems across computer science, engineering, and related disciplines.
Author Contributions
Conceptualization, X.Z. and H.L.; methodology, X.Z. and H.L.; software, X.Z.; validation, X.Z.; formal analysis, X.Z.; investigation, X.Z.; data curation, X.Z.; writing—original draft preparation, X.Z.; writing—review and editing, X.Z. and H.L.; visualization, X.Z. All authors have read and agreed to the published version of the manuscript.
Funding
This research received no external funding.
Data Availability Statement
If readers need the experimental data, please contact the author at: zxqsd@126.com.
Acknowledgments
The authors would like to express their gratitude to multiple AI models (such as ChatGPT, DeepSeek, TRAE, etc.) for their assistance. Their assistance has enhanced the depth and comprehensiveness of their thinking, the speed of paper writing, and the verification of some test results.
Conflicts of Interest
The authors declare no conflict of interest.
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Table 1.
Resource Scheduling Parameters and Performance.
Table 1.
Resource Scheduling Parameters and Performance.
| Parameter Set |
Period L |
Balance |
Utilization |
Vacancy Rate |
|
12 |
0.62 |
50.0% |
50.0% |
|
12 |
0.85 |
83.3% |
16.7% |
|
20 |
1.00 |
100.0% |
0.0% |
|
12 |
0.92 |
91.7% |
8.3% |
Table 2.
Neural Network Performance Comparison.
Table 2.
Neural Network Performance Comparison.
| Model |
Parameters |
Accuracy |
Training Speed |
Memory Use |
| Full Connectivity |
100% |
94.2% |
1.0× |
100% |
| Random Sparsity |
35% |
92.1% |
1.3× |
40% |
| PPM Sparsity |
35% |
93.8% |
1.4× |
40% |
Table 3.
Comparative Performance Analysis.
Table 3.
Comparative Performance Analysis.
| Method |
Coverage |
Balance |
Predictability |
Implementation Complexity |
| Random Pairing |
Variable |
Medium |
Low |
Low |
| Round-Robin |
High |
High |
High |
Low |
| Prime Modulus |
High |
High |
Medium |
Medium |
| Block Cyclic |
Medium |
Medium |
High |
Medium |
| PPM Model |
High |
High |
High |
Medium |
|
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