Index Modulation Tone Reservation PAPR Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wireless communication systems face challenges in reducing peak-to-average power ratio (PAPR) in OFDM transmissions, leading to signal distortion and limited data capacity due to power amplifier limitations.
Innovation Solution
The implementation of index modulation (IM) in OFDM systems, where a set of resource elements includes both active and tone reservation elements, with the latter configured to reduce PAPR by transmitting signals that cancel out peaks, allowing for increased data transmission without distorting the signal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If PAPR is reduced using conventional tone reservation methods, then signal distortion is limited, but spectral efficiency decreases due to reserved resource elements not carrying data
Solution Approach 1:
The patent applies multi-functionality by making reserved resource elements serve dual purposes: they generate peak-cancelling signals for PAPR reduction while simultaneously carrying encoded data bits. This resolves the contradiction by eliminating the waste of reserved resources and improving spectral efficiency without compromising signal quality
Solution Approach 2:
The patent changes the parameter of resource element utilization by encoding data bits into the selection and configuration of reserved resource elements. This transforms previously idle reserved elements into active data carriers, thereby improving spectral efficiency while maintaining PAPR reduction capabilities
2Reliability
If input power is limited to below back-off value to avoid distortion, then PAPR effects are controlled, but data transmission capability is reduced
Solution Approach 1:
The patent applies preliminary action by pre-calculating and embedding peak-cancelling signals into the transmitted waveform before power amplification. This allows the power amplifier to operate at higher power levels without causing distortion, as the peaks have already been cancelled in the frequency domain, thereby improving data transmission capability while maintaining signal quality
Data Source
AI summary
Methods, systems, and devices for wireless communications are described. In one example, a transmitting device may identify first and second portions of data to include in a data transmission. The transmitting device may encode the second portion by a configuration of a first subset of resource elements. The transmitting device may transmit, via the data transmission, first signals representative of the first portion over the first subset and one or more second signals over a second subset of resource elements. A receiving device may receive the data transmission and may identify that the one or more second signals include content other than data of the data transmission. The receiving device may decode the first signals in order to identify the first portion and the configuration in order to identify the second portion. The receiving device may refrain from decoding the one or more second signals based on the identifying.