Phase-Shift Pre-Coding for Wireless MIMO Systems
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Multi-carrier based wireless access techniques fail to adequately support mobile communication systems with various antenna structures, particularly due to increased complexity, channel sensitivity, and memory usage in existing pre-coding and spatial multiplexing methods.
Innovation Solution
A phase-shift based pre-coding method using a unitary matrix for multiple antenna systems, which reduces channel loss and supports various spatial multiplexing rates with reduced complexity and lower channel sensitivity, and requires a low-capacity codebook, allowing for easy expansion with changing antenna numbers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional pre-coding or spatial multiplexing methods are used in multi-carrier wireless access systems, then data transmission capacity can be increased, but device complexity and memory usage increase significantly
Solution Approach 1:
The patent segments the pre-coding operation into two distinct parts: a unitary matrix operation and a phase-shift operation. This segmentation allows each part to be optimized independently - the unitary matrix handles spatial multiplexing while the phase-shift handles diversity, reducing overall system complexity compared to using a single complex pre-coding matrix.
Solution Approach 2:
The patent changes the parameter representation by using phase-shift values (angles) instead of full complex pre-coding matrix elements. This parameter transformation reduces the amount of information that needs to be stored and processed, directly reducing device complexity and memory usage while maintaining data transmission capacity.
2Adaptability or versatility
If existing pre-coding schemes are implemented to support various antenna structures, then system adaptability improves, but channel sensitivity increases
Solution Approach 1:
The patent applies preliminary phase-shift processing to the signal before transmission through the channel. This pre-processing action compensates for expected channel effects, making the system more robust to channel variations and reducing channel sensitivity while maintaining adaptability to different antenna structures.
3Productivity
If space-time coding schemes are used to achieve spatial multiplexing, then spatial multiplexing rates are maintained, but device complexity increases
Solution Approach 1:
The patent extracts the essential spatial multiplexing function from complex space-time coding schemes and implements it through a simplified unitary matrix operation combined with phase-shifting. This extraction maintains the spatial multiplexing rate while removing unnecessary complexity from the original space-time coding approach.
Data Source
AI summary
A phase-shift based pre-coding scheme used in a transmitting side and a receiving side that has less complexity than those of a space-time coding scheme, that can support various spatial multiplexing rates while maintaining the advantages of the phase-shift diversity scheme, that has less channel sensitivity than that of the pre-coding scheme, and that only requires a low capacity codebook is provided.