Per-Symbol OFDM Compression in Digital RoF Optical Links
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Solution Overview
Problem
Conventional digital RoF transmission technologies experience a worsening compression rate when compressing multiple kinds of OFDM symbols, due to differing frequency components and signal properties, leading to reduced efficiency in bandwidth utilization.
Innovation Solution
An optical communication system that determines and uses specific compression and expansion sizes for each OFDM symbol based on acquired symbol information, allowing for compression and expansion processes to be performed independently for each symbol, thereby maintaining optimal compression rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If multiple kinds of OFDM symbols are compressed together using conventional digital RoF transmission, then the transmission bandwidth is utilized, but the compression rate deteriorates due to differing frequency components and signal properties
Solution Approach 1:
The patent segments the compression process by determining and applying specific compression sizes for each individual OFDM symbol rather than using a uniform compression approach. The compression size determination unit calculates optimal compression sizes based on symbol information (starting position and length) for each OFDM symbol, allowing different compression parameters to be applied to different symbol types while maintaining high compression rates across diverse frequency components and signal properties
Solution Approach 2:
The patent applies local quality by adapting the compression size to the specific characteristics of each OFDM symbol. By determining compression sizes based on individual symbol information (starting position and length), the system optimizes compression parameters locally for each symbol type, ensuring that each symbol is compressed with the most appropriate parameters for its specific frequency components and signal properties, thereby maintaining high compression rates
2Device complexity
If uniform compression size is used for all OFDM symbols, then the compression process is simplified, but the compression rate deteriorates due to ignoring symbol-specific characteristics
Solution Approach 1:
The patent segments the compression process into symbol-specific operations where the compression size determination unit calculates optimal compression sizes for each OFDM symbol based on its starting position and length. This segmentation allows the system to maintain relatively simple compression logic while achieving high compression rates by applying appropriate compression parameters to each symbol type individually rather than using a one-size-fits-all approach
Solution Approach 2:
The system performs self-service by automatically determining optimal compression sizes for each OFDM symbol based on its inherent characteristics (starting position and length). The compression size determination unit autonomously calculates the appropriate compression parameters without requiring manual configuration, enabling the system to adapt to different symbol types and maintain high compression rates while keeping the overall process relatively simple
Data Source
AI summary
An optical communication system includes a signal processing apparatus and a wireless apparatus between which functions of a base station are divided, wherein a periodic symbol sequence including a cyclic prefix appended to a signal of a predetermined size to which an IFFT (Inverse Fast Fourier Transform) has been applied is transmitted between the signal processing apparatus and the wireless apparatus by means of digital RoF (Radio over Fiber) transmission, the signal processing apparatus and the wireless apparatus each include a transmission unit and a reception unit, the transmission unit includes: a compression size determination unit that acquires symbol information relating to a starting position of the symbol sequence and lengths of symbols constituting the symbol sequence, and that determines, based on the acquired symbol information, a compression size for each of symbols that are to be compressed; and a compression unit that compresses the symbol sequence in units of determined compression sizes, and the reception unit includes: an expansion size determination unit that determines an expansion size for each of symbols in the symbol sequence that are to be expanded; and an expansion unit that expands the symbol sequence in units of determined expansion sizes.