Multiple Antenna Signal Transmission via Tile Phase Shifting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing multiple antenna transmission systems face a trade-off between channel estimation performance and frequency diversity gain, where increasing cyclic delay improves frequency diversity but deteriorates channel estimation, and decreasing cyclic delay compromises the purpose of using multiple antennas.
Innovation Solution
The system groups subcarrier symbols into tiles with the same phase shifting values within each tile, using multiple phase shifting units and inverse Fast Fourier Transform (IFFT) units to transmit signals through multiple antennas, maintaining low cyclic delay for improved channel estimation while maximizing frequency diversity gain.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If cyclic delay value is increased to improve frequency diversity gain, then frequency diversity gain is improved, but channel estimation performance is deteriorated
Solution Approach 1:
The patent segments the frequency domain resources into multiple tiles, where each tile is a contiguous set of subcarriers. By applying different phase shifting values to different tiles rather than using a uniform cyclic delay across all subcarriers, the system achieves frequency diversity while maintaining better channel estimation performance. This segmentation approach resolves the contradiction by localizing the phase shifting effect to specific frequency regions.
Solution Approach 2:
The patent applies local quality by using different phase shifting values for different tiles in the frequency domain. Instead of applying a uniform cyclic delay (global approach), each tile can have its own phase shifting value optimized for local conditions. This allows the system to achieve frequency diversity gain in each tile while maintaining acceptable channel estimation performance, thus resolving the trade-off contradiction.
2Measurement precision
If cyclic delay value is decreased to improve channel estimation performance, then channel estimation performance is improved, but frequency diversity gain is reduced
Solution Approach 1:
By segmenting the frequency domain into multiple tiles and applying phase shifting at the tile level rather than using a small uniform cyclic delay across all subcarriers, the system maintains low cyclic delay values (improving channel estimation) while still achieving frequency diversity through the multi-tile structure. Each tile contributes to diversity without requiring large overall delays.
Solution Approach 2:
The patent transitions from a time-domain cyclic delay approach (single dimension) to a frequency-domain tile-based phase shifting approach (adding frequency dimension). This dimensional change allows the system to achieve diversity through frequency-domain tile segmentation rather than relying solely on time-domain delays, thus improving channel estimation while maintaining diversity gain.
Data Source
AI summary
The present invention relates to a multiple antenna transmission system and a signal transmission method In the signal transmission method using multiple antennas, a plurality of subcarrier symbols are grouped as a plurality of groups including first and second tiles that are basic resource management units including two or more subcarriers included in a set frequency domain, phases of subcarrier symbols included in a first tile are shifted to be a first phase shifting value, and phases of subcarrier symbols included in a second tile are shifted to be a second phase shifting value that is different from the first phase shifting value.