Signal Demodulation Using Composite Noise Probability
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Solution Overview
Problem
High-order modulation in wireless communication systems is sensitive to phase noise and Gaussian noise, leading to incorrect demodulation results due to the lack of effective anti-phase-noise capabilities in existing demodulation algorithms, especially as modulation order increases and constellation point density grows.
Innovation Solution
A signal demodulation method and device that calculates symbol probability using both Gaussian noise and phase noise standard deviations, along with amplitude and phase information of receive and constellation points, to improve demodulation accuracy by considering both noise types in the demodulation process, employing a formula to determine the likelihood of each constellation point corresponding to the receive signal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high-order modulation is used to increase information transmission rate, then transmission rate is improved, but sensitivity to phase noise and Gaussian noise increases leading to demodulation errors
Solution Approach 1:
The patent changes the parameters used in demodulation by incorporating both Gaussian noise standard deviation (σn) and phase noise standard deviation (σθ) into the probability calculation formula. This parameter change allows the system to maintain high-order modulation benefits while compensating for noise sensitivity through mathematical modeling of both noise types simultaneously.
Solution Approach 2:
The patent creates a composite noise model that combines Gaussian noise and phase noise characteristics into a unified probability calculation framework. By treating the two noise types as composite elements in the demodulation process, the system achieves improved reliability without sacrificing transmission rate, as both noise effects are handled together in the symbol probability calculation.
2Device complexity
If existing demodulation algorithms are used that only consider Gaussian noise, then calculation complexity is reduced, but anti-phase-noise capability is insufficient leading to wrong demodulation results
Solution Approach 1:
The patent introduces phase noise standard deviation (σθ) as an additional parameter to the traditional Gaussian noise-only model. This parameter change enables the system to account for phase noise effects while maintaining a relatively simple probability calculation framework, thus improving anti-phase-noise capability without excessively increasing calculation complexity.
Solution Approach 2:
The patent uses symbol probability as an intermediary mechanism to handle both Gaussian noise and phase noise effects. By calculating symbol probability that incorporates both noise types, the system mediates between the two noise sources and provides a unified decision criterion, improving phase noise resistance while keeping the overall process manageable.
3Reliability
If demodulation algorithms consider both Gaussian noise and phase noise, then anti-phase-noise capability is improved, but calculation complexity increases and processing efficiency decreases
Solution Approach 1:
The patent formulates a probability calculation that incorporates both noise types through a unified mathematical expression involving σn and σθ. This parameter integration allows the system to maintain efficient calculation by using a closed-form probability expression rather than requiring complex iterative algorithms, thus preserving processing efficiency while improving anti-phase-noise capability.
Solution Approach 2:
The patent performs preliminary estimation of noise parameters (Gaussian noise standard deviation and phase noise standard deviation) before the main demodulation process. By pre-calculating or pre-estimating these parameters, the system reduces the computational burden during actual demodulation, maintaining high processing efficiency while still accounting for both noise types in the probability calculation.
Data Source
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AI summary
The present invention provides a signal demodulation method and device. The method includes: obtaining a symbol probability parameter, where the symbol probability parameter comprises: an amplitude rj and a phase angle ϕy of a receive signal, an amplitude rxj and a phase angle ϕxj of each constellation point xj in a decision constellation point set, and a standard deviation σn of Gaussian noise and a standard deviation σθ of phase noise; calculating, according to the symbol probability parameter, a symbol probability that a transmit signal is each constellation point xj in the decision constellation point set; and performing demodulation according to the symbol probability, and outputting demodulation information. The present invention improves an anti-phase-noise capability.