MU-MIMO-OFDM Resource Allocation via Capacity Proportional Power

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Solution Overview

Problem

Current resource allocation methods for MU-MIMO-OFDM systems fail to effectively address the issue of link outage due to path loss and channel fading, leading to suboptimal signal-to-noise ratio and capacity constraints, especially in multi-user environments with varying data transmission sizes.

Innovation Solution

A resource allocation method that assigns preset sub-channel numbers to users based on capacity ratio constraints, using scheduling rules like Max-Min and Max Sum-Rate to optimize sub-channel allocation, ensuring each user selects sub-channels that maximize link quality and meet data size requirements, thereby enhancing coverage and capacity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If power is divided among multiple antennas in MIMO system, then transmission rate is enhanced, but covering range becomes smaller compared to SISO system

Engineering Contradiction:
Improvetransmission rateVSAvoidcovering range
Core Design Contradiction:
ProductivityVSArea of stationary object

Solution Approach 1:

The patent changes the allocation parameters from equal power distribution to capacity-proportional power distribution. By dynamically adjusting the power allocation ratio based on each user's channel capacity, the system achieves both high transmission rates for users with good channels and adequate coverage for users with poor channels, resolving the contradiction between transmission rate enhancement and covering range reduction.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If scheduling algorithm enhances signal strength of weakest antenna, then soft coverage enhancement is achieved, but additional transmit power is required

Engineering Contradiction:
ImprovecoverageVSAvoidtransmit power
Core Design Contradiction:
ReliabilityVSPower

Solution Approach 1:

The patent implements a self-service mechanism where users with better channel conditions automatically provide power to the system through their higher capacity channels. The power allocation algorithm leverages the natural channel diversity, allowing strong channels to carry more power and indirectly support weaker channels through efficient resource utilization, achieving coverage enhancement without additional hardware power.

Inventive Principle:
Principle #25Self-service

3Device complexity

If sub-channel allocation does not consider capacity ratio constraints, then allocation complexity is reduced, but link outage occurs due to path loss and channel fading

Engineering Contradiction:
Improveallocation complexityVSAvoidlink quality
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent applies preliminary action by pre-calculating and establishing capacity ratio constraints before sub-channel allocation. These constraints are derived from channel state information and are used to guide the allocation process, ensuring that users with poor channel conditions are assigned sub-channels that maintain their link quality above outage thresholds, while users with good channels receive sub-channels that maximize system capacity.

Inventive Principle:
Principle #10Preliminary action

4Adaptability or versatility

If flexible transmission rate is provided for each user, then user-specific data size requirements are met, but resource allocation becomes more complex

Engineering Contradiction:
Improveflexible transmission rateVSAvoidresource allocation complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements dynamics by making the power allocation ratio adaptive rather than static. The allocation ratio dynamically adjusts based on real-time channel conditions and user capacity ratios, allowing the system to flexibly meet different user data size requirements. This dynamic approach maintains manageable complexity by using closed-form solutions based on channel state information, avoiding the need for complex iterative optimization.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentUS8165076B2Resource allocation method for multi-users multiple input multiple output orthogonal frequency division multiplexing system and apparaus thereof
Publication Date: 2012.04.24 IND TECH RES INST
  • US8165076B2 patent drawing
  • US8165076B2 patent drawing
  • US8165076B2 patent drawing

AI summary

The present invention is direct to the resource allocation method for MU-MIMO-OFDM system and the apparatus thereof. The MU-MIMO-OFDM system has a plurality of users and a plurality of sub-channels. The sub-channels are assigned to the users according to the capacity ratio constraints and a scheduling rule, and then the power of the user is determined according to the limit power of the MU-MIMO-OFDM system. Wherein the values of power of the sub-channels assigned to the user are the same, the scheduling rule may be Max-Min or Max Sum-Rate rule, and the allocation of the sub-channels may be user-oriented or sub-channel oriented.