Single Photon Communication Frequency Coding
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Solution Overview
Problem
Existing communication technologies face low channel capacity when receiving communication light at the single-photon level due to low signal-to-noise ratio and high noise levels, particularly in extreme conditions like ultra-distance or adverse weather, limiting effective information transmission.
Innovation Solution
A single-photon communication method employing a multi-channel frequency coding scheme, where information is encoded by modulating the emission probability or quantum state of light, allowing for spectral analysis by a single-photon detector to recover the original modulation frequency and decode information, thereby enhancing channel capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If integration time is extended to improve signal-to-noise ratio at single-photon level, then measurement precision is improved, but channel capacity deteriorates due to extremely low transmission rate
Solution Approach 1:
The patent segments the frequency spectrum into multiple channels, allowing parallel detection of multiple frequency components in the single-photon signal. This enables information encoding across multiple frequency bins simultaneously, increasing channel capacity without requiring longer integration times for each individual measurement.
Solution Approach 2:
The patent transitions from temporal domain integration to frequency domain analysis by applying spectral estimation to the detected photon arrival times. This dimensional transformation allows extraction of multiple independent information channels from the same photon stream, resolving the trade-off between integration time and channel capacity.
2Adaptability or versatility
If photon counting is performed at single-photon level to meet extreme communication requirements, then adaptability is improved, but measurement precision deteriorates due to shot noise
Solution Approach 1:
The patent replaces direct temporal integration methods with spectral estimation techniques that analyze the frequency content of photon arrival times. This substitution allows discrimination of signal from shot noise through frequency domain filtering, maintaining measurement precision while enabling single-photon level detection for extreme communication scenarios.
3Productivity
If multi-channel frequency coding is implemented to increase channel capacity, then productivity is improved, but device complexity increases due to spectral analysis requirements
Solution Approach 1:
The patent employs algorithms that exploit the inherent statistical properties of photon arrival processes to perform spectral estimation. By utilizing the natural Poisson statistics of single-photon detection, the system achieves multi-channel frequency decoding through computational methods rather than requiring complex physical spectral analysis hardware, thereby reducing device complexity while maintaining high channel capacity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The multi-channel frequency coding scheme significantly improves channel capacity at the single-photon level, enabling reliable information transmission even in high-loss and noisy environments, such as interstellar or satellite-ground communication, by breaking sampling theorem limitations and utilizing quantum statistical properties.
Implementation Method 1
a single-photon detector is introduced and information may be coded by using a multi-channel frequency coding scheme
Data Source
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AI summary
A single photons communication method and system is provided. In an example, an information loading module in a transmitting terminal of the single photons communication system may code to-be-sent target information as a corresponding target modulation frequency according to a pre-saved relationship between information and modulation frequency, and perform frequency modulation on a quantum state of communication light generated by a light source by using the target modulation frequency so that the transmitting terminal may send out modulated target communication light. After receiving the target communication light, an information decoding module in a receiving terminal of the single photons communication system may decode the target modulation frequency from a sequence of receiving photons of the target communication light through Fourier transform or other ways, and obtain target information corresponding to the target modulation frequency according to the relationship between information and modulation frequency.