OFDM Peak Reduction Kernel Selection for PAPR Compensation
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Solution Overview
Problem
OFDM systems face challenges in effectively compensating for Peak-to-Average Power Ratio (PAPR) due to changes in the position of reserved tones used for other purposes, making it difficult to detect and apply an optimal Peak Reduction Kernel, which reduces PAPR reduction efficiency.
Innovation Solution
Storing Peak Reduction Kernels corresponding to different types of data symbols and selecting the appropriate kernel based on the current symbol type to compensate PAPR, even when the position of reserved tones changes, allowing for effective PAPR compensation without additional data transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If Peak Reduction Kernel is carried by reserved tones, then PAPR can be compensated, but it becomes difficult to detect optimum Peak Reduction Kernel when reserved tones positions change
Solution Approach 1:
The patent applies preliminary action by pre-storing multiple Peak Reduction Kernels corresponding to different reserved tone positions before transmission. The receiver can directly select the appropriate pre-stored kernel based on the detected reserved tone positions, eliminating the need for complex real-time detection and optimization processes.
Solution Approach 2:
The patent changes the parameter of Peak Reduction Kernel selection from a dynamic optimization process to a static selection based on predetermined categories. By categorizing reserved tone positions and pre-storing corresponding kernels for each category, the system transforms the continuous parameter space into discrete selectable options.
2Reliability
If multiple Peak Reduction Kernels are stored for different symbol types, then PAPR compensation can be applied according to symbol type, but storage requirements and system complexity increase
Solution Approach 1:
The patent applies local quality by storing different Peak Reduction Kernels for different data symbol types (e.g., pilot symbols, data symbols, null symbols). Each symbol type has its own optimized kernel stored in memory, allowing the receiver to select the most appropriate kernel based on the current symbol type being processed.
Solution Approach 2:
The system performs preliminary action by pre-categorizing and pre-storing Peak Reduction Kernels according to different symbol types before actual transmission. This eliminates the need for real-time kernel generation or complex optimization algorithms during reception, reducing computational complexity.
3Productivity
If reserved tones are used for multiple purposes including pilot transmission, then tone utilization efficiency improves, but available tones for PAPR compensation decrease
Solution Approach 1:
The patent applies universality by designing a Peak Reduction Kernel selection mechanism that works effectively regardless of which specific tones are reserved for different purposes. The system can handle various reservation patterns (pilot tones, data tones, null tones) using the same fundamental approach of detecting reserved tone positions and selecting corresponding pre-stored kernels.
Data Source
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AI summary
An orthogonal frequency division multiplexing (OFDM) transmission apparatus is provided which includes a data processing unit which generates a transmission signal using a plurality of tones including a reserved tone, a storage unit which stores Peak Reduction Kernel information according to the type of data symbol, and a compensation unit which retrieves the Peak Reduction Kernel information according to the type of data symbol from the storage unit and causes the retrieved information to be carried by the reserved tone included in the transmission signal. Therefore, a Peak-to-Average Power Ratio (PAPR) can be efficiently compensated.