Multicarrier Transmitter Peak-to-Average Power Reduction Kernel Signal
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Solution Overview
Problem
Multicarrier modulation systems face challenges due to high peak-to-average signal ratio (PAR) values, which demand large dynamic range for analog circuits and digital processing, leading to increased power consumption and cost, especially in high-speed communication systems like VDSL2 and G.fast.
Innovation Solution
A method to reduce PAR in multicarrier transmitters by generating a kernel signal from subcarriers used for data transmission, scaling and shifting it based on peak locations and amplitudes, and combining it with the multicarrier data signal to create a digital signal with a lower PAR, without reserving separate subcarriers for PAR reduction, thus approximating a dirac-delta function and eliminating the need for iterative peak cancellation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional multicarrier modulation is used to achieve high data rates, then data transmission capacity is improved, but peak-to-average power ratio increases leading to higher power consumption and cost
Solution Approach 1:
The patent combines the data-carrying function and PAR reduction function into a single integrated process. The kernel signal is constructed from the same subcarriers that carry data, merging what were previously separate functions (data transmission and PAR reduction) into one unified approach that achieves both simultaneously without requiring separate dedicated subcarriers for PAR reduction
2Reliability
If separate subcarriers are reserved for PAR reduction, then peak power is reduced, but data rate decreases due to fewer subcarriers available for data transmission
Solution Approach 1:
The patent makes the subcarriers universal by enabling them to serve multiple purposes simultaneously. The same subcarriers that carry data are also used to construct the kernel signal for PAR reduction, eliminating the need for dedicated PAR reduction subcarriers and maximizing the utility of each subcarrier for both data transmission and peak power control
3Reliability
If iterative peak cancellation methods are used, then PAR reduction is achieved, but computational complexity and processing time increase
Solution Approach 1:
The patent performs preliminary action by constructing the kernel signal in advance from the available subcarriers before the actual data transmission occurs. This pre-computed kernel signal can then be applied directly without requiring iterative adjustments during transmission, reducing real-time computational complexity while maintaining effective PAR reduction
Data Source
AI summary
A transmitter for performing multicarrier modulation comprising a processing unit configured to generate a multicarrier data signal comprising a plurality of subcarriers, wherein each of the plurality of subcarriers represents at least one data bit of a plurality of data bits, select a subset of the subcarriers based on signal quality information about one or more of the subcarriers, construct a kernel signal comprising the subset of subcarriers, and create a digital signal comprising combining the multicarrier data signal and a peak-to-average ratio (PAR) reduction signal based on the kernel signal, wherein a PAR of the digital signal is less than a PAR of the multicarrier data signal.