PUCCH Sequence Mapping for Low PAPR and Low Correlation
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Solution Overview
Problem
The existing 30 length-12 root sequences in the LTE system fail to ensure both low correlation and small Peak-to-Average Power Ratio (PAPR) and Cubic Metric (CM) values for PUCCH signals, leading to interference and degraded reception performance.
Innovation Solution
A sequence-based signal processing method that determines a sequence {fn} consisting of 12 elements, mapped to 12 subcarriers, ensuring low correlation and small PAPR and CM values by using specific sequence sets and equivalent sequences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the existing 30 length-12 root sequences are used for PUCCH signal transmission, then the sequence correlation can be kept low, but the PAPR and CM values cannot be ensured to be small simultaneously
Solution Approach 1:
The patent changes the parameters of the sequences by introducing a phase rotation factor exp(2πjαn) to the existing root sequences. This parameter modification transforms the original sequences into new sequences that maintain low correlation properties while achieving smaller PAPR and CM values, thereby resolving the contradiction between reliability and harmful factors.
Solution Approach 2:
The patent creates composite sequences by combining the existing root sequences with phase rotation factors. This composite approach integrates the low correlation property of the original sequences with the PAPR-reducing effect of the phase rotation, producing a new sequence structure that simultaneously achieves both desired properties.
2Object-affected harmful factors
If the PAPR value is reduced for PUCCH signals, then the CM value is certainly reduced, but the sequence correlation and coverage cannot be ensured
Solution Approach 1:
By adjusting the phase rotation parameter α in the sequence formulation fn=A·xn·exp(2πjαn), the patent achieves optimal balance between PAPR reduction and maintaining sequence correlation properties. This parameter optimization ensures that coverage and reliability are preserved while PAPR is reduced.
Solution Approach 2:
The patent generates multiple equivalent sequences by applying different phase rotation factors to the same root sequence. These copied sequences maintain the same correlation properties but have different PAPR characteristics, allowing selection of the optimal sequence for each transmission condition.
Data Source
AI summary
A sequence-based signal processing method and apparatus are provided. A sequence meeting a requirement for sending a signal by using a physical uplink control channel (PUCCH) is determined. The sequence is a sequence {fn} consisting of 12 elements, fn represents an element in the sequence {fn}, and the determined sequence {fn} is a sequence meeting a preset condition. Then, the 12 elements in the sequence {fn} are respectively mapped to 12 subcarriers, to generate a first signal, and the first signal is sent. By using the determined sequence, when the signal is sent by using the PUCCH, a low correlation between sequences can be maintained, and a relatively small peak-to-average power ratio (PAPR) value and a relatively small cubic metric (CM) value can be maintained. Therefore, a requirement of a communication application environment in which the signal is sent by using the PUCCH is met.