Sequence-Based Signal Processing for Low PAPR PUCCH
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Solution Overview
Problem
Existing root sequences in LTE systems fail to maintain low sequence correlation, peak to average power ratio (PAPR) values, and cubic metric (CM) values, which are essential for efficient signal processing in communication applications.
Innovation Solution
A sequence-based signal processing method is introduced, where a sequence {fn} is determined and mapped to N subcarriers to generate a signal. The sequence {fn} is defined as A·xn·e2π·j·a·n, where A is a non-zero complex number, a is a real number, and xn is a complex number, ensuring low sequence correlation and small PAPR and CM values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If 30 existing length-N root sequences are used in LTE system, then sequence correlation is optimized, but PAPR values become large
Solution Approach 1:
The patent applies parameter changes by modifying the mathematical structure of the sequence from traditional root sequences to a new form: fn=A·xn·e2π·j·a·n, where A is a non-zero complex number, a is a real number, and xn is from the original root sequence. This parameter transformation maintains low sequence correlation while significantly reducing PAPR values, resolving the contradiction between reliability and energy efficiency.
2Reliability
If CM value is optimized for 30 root sequences, then sequence correlation is improved, but PAPR value cannot be ensured small
Solution Approach 1:
The patent transforms the sequence parameters by introducing a complex exponential term e2π·j·a·n multiplied by the original root sequence xn. This parameter modification decouples the relationship between CM value optimization and PAPR value, allowing independent control where low CM value maintains sequence correlation while the exponential term adjusts PAPR characteristics.
3Adaptability or versatility
If length-24 CGS is used in LTE, then sequence coverage is expanded, but PAPR values become large (ranging from 2.6239 to 4.2962)
Solution Approach 1:
The patent applies parameter changes to the length-24 CGS by transforming it into the new sequence form fn=A·xn·e2π·j·a·n. This transformation maintains the sequence length and coverage properties while significantly reducing PAPR values through the exponential term modulation, resolving the contradiction between adaptability and energy efficiency.
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, where the sequence is a sequence {fn} consisting of N elements, fn is an element in the sequence {fn}, and the determined sequence {fn} is a sequence meeting a preset condition; then, the N elements in the sequence {fn} are respectively mapped to N subcarriers to generate a first signal; and the first signal is sent. By using the determined sequence, when a signal is sent by using a PUCCH, a low sequence correlation can be maintained, and a relatively small peak-to-average power ratio (PAPR) value and cubic metric (CM) value can also be maintained, thereby meeting a requirement of a communication application environment in which a signal is sent by using a PUCCH.