MU-MIMO Power Allocation via Utility Metric Optimization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional MU-MIMO systems employ naive power allocation schemes that allocate equal transmission power to each user equipment (UE), which is inadequate for maximizing system performance due to interference and varying channel conditions.
Innovation Solution
A system that allocates downlink transmit power in a MU-MIMO system by identifying receivers, receiving channel state information, constructing a precoder, and deriving power-scale factors based on a utility function such as proportional fairness (PF) weighted sum rate, while applying power constraints to ensure optimal power distribution and reduce excessive transmit power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If equal transmission power is allocated to each UE, then the power allocation scheme is simple to implement, but the system throughput and spectral efficiency are not optimized due to interference and varying channel conditions
Solution Approach 1:
The patent applies local quality by deriving individual power-scale factors for each UE based on their specific channel conditions, utility function weights, and interference characteristics. Instead of uniform power allocation, each receiver receives customized power scaling that optimizes its individual performance while considering system-wide constraints, thereby improving overall throughput without excessive complexity
Solution Approach 2:
The patent changes the power allocation parameter from fixed equal power to dynamic power-scale factors derived from utility function optimization. The power-scale factors are calculated based on channel state information, utility weights, and power constraints, allowing the system to adapt power distribution to varying channel conditions and user priorities, thus improving spectral efficiency
2Productivity
If power-scale factors are derived to optimize utility function, then spectral efficiency is improved, but power constraint requirements may be violated
Solution Approach 1:
The patent applies preliminary anti-action by incorporating power constraint requirements directly into the utility function optimization process. Before power allocation is finalized, the system checks whether derived power-scale factors violate transmitter power constraints and adjusts them accordingly, preventing constraint violations rather than correcting them after the fact
Solution Approach 2:
The patent applies dynamics by making the power allocation adaptive and iterative. The system derives power-scale factors based on current channel conditions and utility requirements, checks power constraints, and adjusts allocations dynamically. This allows the system to maintain reliability while optimizing spectral efficiency under varying conditions
3Ease of operation
If conventional naive power allocation is used, then implementation is straightforward, but interference management is inadequate and system performance is limited
Solution Approach 1:
The patent applies feedback by using channel state information (CSI) to derive power-scale factors. The system receives CSI from UEs, uses this feedback to calculate appropriate power allocations that account for current interference conditions, and adjusts power distribution accordingly. This closed-loop approach enables effective interference management while maintaining reasonable implementation complexity
Data Source
AI summary
A system is provided for allocating downlink transmit power in a wireless multiple-input multiple-output (MIMO) system. During operation, the system identifies a set of receivers for receiving signals from one or more transmitters on a same time-frequency slot, receives channel state information (CSI) for communication channels between the identified receivers and the transmitters, and constructs a precoder based on the CSI. The system further derives a set of power-scale factors for the precoder based on a utility function associated with the identified receivers such that the power-scale factors optimize the utility function. A respective power-scale factor scales power transmitted to a corresponding receiver.