OFDM Signal Extrema Attenuation via Interleaved Peak Vector Correction
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Solution Overview
Problem
Multicarrier OFDM signals experience significant amplitude fluctuations, leading to high peak-to-average power ratio (PAPR), which results in inefficient power consumption and increased computational complexity in existing methods for reducing extrema, making them unsuitable for modern broadcast standards.
Innovation Solution
A method that interleaves source symbols into sub-blocks, applies discrete Fourier transform, and corrects constellation symbols based on a peak vector to attenuate extrema, reducing the complexity and energy consumption of the system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If clipping is applied to limit signal amplitude, then extrema are reduced, but signal distortion increases and bit error rate degrades
Solution Approach 1:
The patent modifies the constellation diagram parameters by adding a peak reduction component that adjusts symbol amplitudes and phases to avoid constructive interference causing extrema, thereby reducing PAPR without clipping and maintaining signal integrity
Solution Approach 2:
The patent introduces an intermediary peak reduction processing stage between modulation and transmission that uses calculated correction vectors to adjust constellation symbols, serving as a mediator that reduces extrema while preserving signal quality
2Object-affected harmful factors
If constraint coding is applied to limit signal fluctuations, then extrema are reduced, but spectral efficiency is penalized and computational complexity increases
Solution Approach 1:
The patent segments the constellation symbols into individual components that can be independently adjusted using peak reduction vectors, allowing localized corrections without requiring complex global optimization algorithms
Solution Approach 2:
The patent changes the parameters of constellation symbols by applying calculated peak reduction vectors that modify amplitude and phase, achieving extrema reduction through straightforward parameter adjustment rather than complex constraint coding
3Reliability
If power stages are sized to deliver maximum peak instantaneous power, then signal extrema are handled, but power consumption increases significantly
Solution Approach 1:
The patent applies preliminary peak reduction processing to the modulating signal before transmission, pre-eliminating extrema that would otherwise require oversized power stages, thereby enabling more efficient power amplifier sizing and operation
Data Source
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AI summary
A method for generating a multicarrier OFDM signal comprising OFDM blocks consisting of M carriers modulated by M source symbols is proposed. The method comprises the following steps: interlacing (100) the M symbols of a block of source symbols into R sub-blocks of N interlaced symbols; obtaining (101) a block of M time-domain samples corresponding to the block of M source symbols; forming (102) a peak vector containing N maximum amplitudes determined from the M samples; attenuating (103) the extrema of each sub-block of N time-domain samples corresponding to the R sub-blocks of N interlaced symbols via a symbol correction taking into account the peak vector and delivering R sub-blocks of N corrected interlaced symbols; deinterlacing (104) the R sub-blocks of N corrected interlaced symbols delivering a block of M corrected source symbols; and generating (105) an OFDM block of the signal corresponding to the block of M corrected source symbols.