Uplink Reference Signal Generation via Phase Rotation
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Solution Overview
Problem
Current wireless communication systems face challenges in generating sequences for uplink reference signals that balance good correlation and Cubic Metric (CM) characteristics with the need for a large number of sequences for efficient cell planning and reduced memory capacity.
Innovation Solution
A method is provided for generating and transmitting uplink reference signals using a base sequence with specific phase parameters, allowing for cyclic shifts and mappings to subcarriers, which includes using Zadoff-Chu sequences with cyclic extension or truncation to achieve desired sequence lengths and characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional sequences are used for uplink reference signals, then good correlation characteristics are achieved, but the number of available sequences is limited and memory capacity increases
Solution Approach 1:
The patent segments the base sequence into multiple parts and applies different phase rotations to each segment. This segmentation allows generation of multiple distinct sequences from a single base sequence, thereby increasing the number of available sequences while maintaining good correlation characteristics through the structured phase rotation approach
Solution Approach 2:
The patent changes the phase parameter p(n) of the base sequence xu(n)=ejp(n)π/4 to generate different reference signal sequences. By varying the phase parameters systematically, multiple sequences with good correlation properties can be generated from a single base sequence, resolving the contradiction between sequence quantity and correlation quality
2Productivity
If more sequences are generated for cell planning, then cell planning efficiency improves, but memory capacity requirements increase
Solution Approach 1:
The patent creates a universal base sequence that can generate multiple reference signal sequences through phase rotations and cyclic shifts. This multi-functional approach allows a single base sequence to serve multiple cell planning purposes, increasing cell planning efficiency without proportionally increasing memory capacity requirements
Solution Approach 2:
The patent generates multiple sequences by creating phase-rotated copies of a base sequence rather than storing completely independent sequences. This copying approach with phase modifications allows efficient generation of multiple sequences for cell planning while reducing memory requirements compared to storing full independent sequences
3Measurement precision
If sequences with good correlation characteristics are used, then detection performance improves, but Cubic Metric characteristics deteriorate
Solution Approach 1:
The patent carefully selects and adjusts the phase parameter p(n) in the base sequence to achieve an optimal balance between correlation characteristics and Cubic Metric. By modifying the phase parameters, the patent can control the peak-to-average power ratio and Cubic Metric while maintaining good correlation properties for detection
Solution Approach 2:
The patent applies different phase rotations to different segments or positions within the sequence, allowing local optimization of both correlation characteristics and Cubic Metric properties. This local quality adjustment enables good detection performance in correlation-critical regions while controlling Cubic Metric in power amplifier-critical regions
Data Source
AI summary
A method of generating a reference signal includes acquiring a base sequence and acquiring a reference signal sequence with a length N from the base sequence. Good PAPR/CM characteristics of the reference signal can be kept to enhance performance of data demodulation or uplink scheduling.