Optical Data Signal Decoder with Adaptive Noise Estimation
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Solution Overview
Problem
Holographic storage systems face interference issues due to closely spaced bits and electronic noise, leading to errors in data retrieval, which existing decoding techniques struggle to effectively mitigate.
Innovation Solution
A method and system for decoding optical data signals that estimate source data based on expected optical and electronic noise distributions, using a detector, decoder, and memory component with algorithms and a look-up table to reduce noise impact, specifically employing a 16-state MAP decoder and modified noise distributions to improve bit error rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If holographic storage systems use closely spaced bits to increase storage capacity, then storage capacity is improved, but bit error rate increases due to interference from adjacent tracks and layers
Solution Approach 1:
The patent changes the parameters of the decoding process by using adaptive noise variance estimation and modified probability distribution functions that account for both optical and electronic noise characteristics. This allows the system to maintain high storage capacity while improving bit error rate performance through optimized decoding parameters
Solution Approach 2:
The patent introduces an intermediary decoding process that acts as a mediator between the noisy optical signal and the stored data. The decoder uses intermediate probability calculations and noise modeling to separate the actual data from the interference caused by closely spaced bits, enabling high capacity storage with reduced errors
2Device complexity
If conventional decoding techniques are used to retrieve data, then device complexity is kept low, but noise interference from optical and electronic sources cannot be effectively mitigated
Solution Approach 1:
The patent modifies the decoding parameters by incorporating adaptive noise variance estimation and using probability distribution functions that specifically model both optical and electronic noise. This enhanced parameter set allows the decoder to effectively mitigate noise interference while maintaining reasonable computational complexity
Solution Approach 2:
The patent performs preliminary noise characterization and variance estimation before the main decoding process. By pre-characterizing the noise properties of both optical and electronic sources, the system prepares optimized decoding parameters in advance, enabling effective noise mitigation during data retrieval without excessive real-time computational complexity
Data Source
AI summary
The present techniques provide systems and methods for decoding an optical data signal in an optical system to retrieve source information while decreasing errors resulting from optical and electronic noise in the optical system. The techniques involve using decoding algorithms to estimate the a posteriori state probabilities and the a posteriori transition probabilities of the data encoding, and estimating bit state probabilities. The probability density function used to estimate bit states is parameterized by the expected optical and electronic noise in the optical system. Different optical and electronic noise variances, or different probability densities, may be stored in registers or look-up tables to be accessed by a decoder while decoding the optical data signal.