Grouped Subcarrier Power Allocation in MIMO Systems
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Solution Overview
Problem
Conventional OFDM systems with multiple antennas do not effectively utilize channel power differences between groups, leading to suboptimal transmission performance due to fixed transmission weights for each subcarrier, which are normalized across all antennas.
Innovation Solution
The method involves grouping subcarriers into multiple groups and calculating transmission power weights for each group using channel information or a code book index, determining antenna transmission vectors, and allocating transmission power to improve efficiency by considering channel changes between groups.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If fixed transmission weights normalized across all antennas are used, then device complexity is reduced, but transmission efficiency deteriorates due to inability to utilize channel power differences between groups
Solution Approach 1:
The patent divides subcarriers into multiple groups and calculates transmission power weights separately for each group based on channel conditions. This segmentation allows the system to exploit channel power differences between groups while maintaining manageable complexity through group-based processing rather than individual subcarrier processing.
Solution Approach 2:
The patent applies different transmission power weights to different subcarrier groups according to their specific channel conditions. By making transmission weights locally optimized for each group rather than uniformly applied, the system improves transmission efficiency while avoiding the complexity of individual subcarrier optimization.
2Ease of operation
If transmission power is uniformly allocated across all subcarriers, then ease of operation is improved, but transmission performance deteriorates due to ignoring channel power differences between groups
Solution Approach 1:
The patent segments subcarriers into groups and allocates power at the group level rather than individually. This approach maintains operational simplicity by reducing the number of power allocation decisions while still capturing channel power differences through group-based differentiation.
Solution Approach 2:
The patent changes the power allocation parameter from a uniform value across all subcarriers to group-specific values based on channel conditions. This parameter change enables the system to adapt to channel variations while maintaining relatively simple operation through group-based control.
Data Source
AI summary
In a method for allocating transmission power in a communication system including multiple antennas, a plurality of subcarriers are grouped by a plurality of groups, and each group includes at least one subcarrier. A transmission power weight and an antenna transmission vector are calculated for each group by using channel information, a transmission power for each group of each antenna is calculated by using the transmission power weight and the antenna transmission vector for each group, and transmission signals are transmitted through the multiple antennas after determining which signals need to be transmitted from the multiple antennas by using the transmission power.