Chaotic Spreading Codes for Drift-Free Synchronization
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Solution Overview
Problem
Current chaos-based communications systems suffer from low throughput due to drift in analog chaotic circuits, requiring frequent synchronization of transmitters and receivers, and non-coherent systems compromise on throughput and error rates.
Innovation Solution
The use of orthogonal or statistically orthogonal chaotic spreading codes generated by different sets of polynomial equations, with residue number system arithmetic, to create coherent spread spectrum communications signals that can be synchronized in time and frequency, allowing for concurrent transmission over a common RF frequency band.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If analog chaotic circuits are used to generate chaotic signals, then chaotic properties are achieved, but drift occurs requiring frequent synchronization which reduces throughput
Solution Approach 1:
The patent replaces analog chaotic circuits with a digital implementation using polynomial equations and residue number system arithmetic. This substitution eliminates the drift problem inherent in analog circuits while maintaining chaotic signal properties, thereby resolving the contradiction between signal stability and throughput.
Solution Approach 2:
The patent changes the fundamental parameters of chaotic signal generation from continuous analog values to discrete digital values using polynomial equations. By using residue number system arithmetic with carefully selected moduli, the system achieves drift-free operation while maintaining the necessary chaotic characteristics for secure communication.
2Measurement precision
If state information is exchanged frequently to correct drift, then synchronization is maintained, but data transmission rate is reduced
Solution Approach 1:
The patent extracts and eliminates the drift problem by using digital polynomial-based chaotic generation instead of analog circuits. Since the digital implementation is drift-free, the harmful synchronization requirement is removed entirely, allowing full data transmission capacity to be utilized.
3Device complexity
If multiple pseudo-random number generators are used to generate chaotic-like sequences, then complexity increases, but true chaotic properties are not achieved
Solution Approach 1:
The patent substitutes pseudo-random number generation with true chaotic signal generation based on polynomial equations and residue number system arithmetic. This replacement achieves authentic chaotic properties with deterministic yet unpredictable sequences, resolving the contradiction between complexity and chaotic authenticity.
Data Source
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AI summary
Methods for code-division multiplex communications. The methods involve generating orthogonal or statistically orthogonal chaotic spreading codes (CSC1,..., CSCK) using different sets of polynomial equations (fo(x(nT)),..., fN-1,(x(nT))), different constant values (Co, Ci,..., CN-1 for the polynomial equations, or different sets of relatively prime numbers (?o, pi,..., pN-1) as modulus (m0, m1,..., mN-?) in solving the polynomial equations. The methods also involve forming spread spectrum communications signals using the orthogonal or statistically orthogonal chaotic spreading codes, respectively. The methods further involve concurrently transmitting the spread spectrum communications signals over a common RF frequency band.