Wireless Encoding Modulation PAPR Reduction
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Solution Overview
Problem
Certain wireless communication protocols, such as IEEE 802.11 standards, face increased transmission error rates due to modulation schemes that enhance spectral efficiency but may not effectively manage peak-to-average power ratios (PAPR), leading to limitations in peak power transmission and increased bit error rates, especially at high frequencies like 60 GHz.
Innovation Solution
The method involves selecting a data rate and mode that defines a modulation scheme and target code rate, modifying error correcting block formats to generate encoded data at the target code rate, and extracting this data for modulation, using techniques like shortening error correcting block formats and employing circular constellation diagrams to reduce PAPR, allowing higher average power transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high-order modulation schemes are used to increase spectral efficiency, then data transmission rate is improved, but bit error rate increases due to increased sensitivity to noise and distortion
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the modulation order and code rate based on channel conditions. The system selects from multiple modulation schemes (BPSK, QPSK, 16-QAM, 64-QAM, 256-QAM) and code rates (5/6, 4/5, 3/4, 2/3, 1/2) to optimize the trade-off between spectral efficiency and error rate, directly resolving the contradiction between transmission rate and reliability
Solution Approach 2:
The patent implements feedback through acknowledgment (ACK) and negative acknowledgment (NACK) mechanisms. The receiving station sends feedback signals to indicate successful reception or transmission errors, allowing the transmitting station to adaptively adjust modulation and coding parameters in subsequent transmissions, thereby maintaining reliability while maximizing data rate
2Productivity
If modulation schemes with high spectral efficiency are used, then data rate is improved, but peak-to-average power ratio increases leading to transmission errors
Solution Approach 1:
The patent changes the modulation parameter set to include circular constellation diagrams (8-PSK, 16-PSK, 32-PSK) alongside traditional QAM schemes. Circular constellations inherently provide lower PAPR compared to square QAM constellations, allowing the system to maintain high spectral efficiency while reducing peak power requirements and avoiding transmission errors in power-limited scenarios
Solution Approach 2:
The patent employs composite modulation schemes that combine different constellation types (circular PSK and rectangular QAM) within the same communication framework. This allows selective use of circular constellations when low PAPR is needed and rectangular QAM when maximum spectral efficiency is required, effectively managing the PAPR issue while maintaining high data rates
3Ease of operation
If error correcting block formats with fixed code rates are used, then decoding simplicity is maintained, but flexibility in adapting to different data rates is limited
Solution Approach 1:
The patent introduces dynamic adaptability by allowing the system to select from multiple predefined error correcting block formats with different code rates (5/6, 4/5, 3/4, 2/3, 1/2) and multiple tail-biting convolutional code rates. The receiving station can dynamically choose the appropriate format based on channel conditions and data rate requirements, maintaining decoding simplicity through standardized formats while achieving flexibility through selective adaptation
Data Source
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AI summary
A wireless communications assembly and method for encoding and modulating data for transmission is provided. The method includes receiving primary data to be transmitted to a receiving station; selecting a data rate at which to transmit the primary data; selecting a mode associated with the data rate, the mode defining a modulation scheme and a target code rate; generating encoded data, including modifying an error correcting block format having a predefined code rate to generate the encoded data at the target code rate; and extracting at least a portion of the encoded data for modulation of a carrier signal and transmission to a receiving station.