Waveform Generation Reducing PAPR in OFDM Systems
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Solution Overview
Problem
Existing communication systems face inefficiencies due to high peak-to-average-power-ratio (PAPR) in Orthogonal Frequency Division Multiplexing (OFDM) waveforms, which leads to power inefficiency in transmitting multiple user data.
Innovation Solution
A method and system that multiplexes data from multiple users, performs a rotation operation, and transforms it using Fourier transform, followed by mapping with a predefined number of subcarriers to generate a waveform with reduced PAPR, utilizing a communication system comprising a transceiver, multiplexer, and processor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If OFDM waveform is used for multiplexing multiple user data, then data transmission capability is improved, but PAPR increases causing power inefficiency
Solution Approach 1:
The OFDM signal is segmented by separating the data stream into multiple parallel subcarriers, each carrying a portion of the data. This segmentation allows for independent modulation and transmission on each subcarrier, enabling the application of precoding techniques that reduce the overall PAPR of the composite signal while maintaining the high data transmission capability of OFDM.
Solution Approach 2:
The invention changes the modulation parameters by applying precoding transformations (such as DFT precoding) to the data before OFDM modulation. This parameter transformation modifies the signal characteristics to achieve lower PAPR while preserving the spectral efficiency and data transmission rate of the original OFDM system.
2Loss of energy
If DFT pre-coded OFDM is used to reduce PAPR, then power efficiency is improved, but inherent power efficiency remains suboptimal
Solution Approach 1:
The invention combines multiple processing techniques into a composite waveform generation approach: DFT precoding is combined with optimized subcarrier mapping and iterative PAPR reduction algorithms. This composite approach integrates the advantages of each technique to achieve superior power efficiency that overcomes the limitations of DFT pre-coded OFDM used in isolation.
Solution Approach 2:
The system implements feedback mechanisms where the PAPR of the generated waveform is evaluated and used to adjust the precoding parameters and subcarrier mapping configuration. This closed-loop optimization continuously improves power efficiency by adapting the waveform characteristics based on measured performance, overcoming the static nature of conventional DFT pre-coded approaches.
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 solution effectively reduces PAPR, enhancing power efficiency and enabling efficient transmission of multiple user data while maintaining low bit error rates.
Implementation Method 1
transforming the rotated data using Fourier transform to produce transformed data
Data Source
AI summary
Embodiments of the present disclosure relate to a communication system to generate a waveform by multiplexing multiple user data. The system comprises at least one transceiver, a multiplexer and a processor. The at least one transceiver configured to perform at least one of receiving a plurality of data from a transmitter, and transmitting a generated waveform to a destination. The multiplexer configured to multiplex a plurality of data associated with a plurality of users, to generate multiplexed data. The processor is configured to perform a rotation operation on the multiplexed data to produce a rotated data. Also, the processor is configured to transform the rotated data using Fourier transform to produce transformed data. Further, the processor is configured to map the transformed data using a predefined number of subcarriers to produce a mapped data sequence and thereafter, process the mapped data sequence to generate the waveform.