MIMO Precoder Optimization for Wireless Multicast Efficiency

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current wireless communication systems employing MIMO schemes face inefficiencies in spectral usage when broadcasting or multicasting data, particularly due to suboptimal pre-coding and resource allocation, which can lead to reduced spectral efficiency and increased power consumption.

Innovation Solution

A method is introduced that optimizes pre-coders and resource units for transmitting public data to multiple terminals using a MIMO scheme, where optimized pre-coders and resource units are determined based on channel quality feedback to adapt transmission to the instantaneous conditions of each terminal, enhancing spectral efficiency and power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If traditional broadcast transmission with fixed pre-coders is used, then implementation simplicity is maintained, but spectral efficiency deteriorates due to inability to adapt to instantaneous channel conditions

Engineering Contradiction:
Improvespectral efficiencyVSAvoidtransmission optimization complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies dynamics by transitioning from fixed pre-coders to dynamic pre-coder selection. The base station determines optimized pre-coders and resource unit quantities based on instantaneous channel quality information from multiple terminals, allowing the transmission parameters to adapt dynamically to changing channel conditions, thereby improving spectral efficiency

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes transmission parameters (pre-coders and resource unit quantities) based on channel quality feedback. By selecting from multiple candidate pre-coders and adjusting resource unit allocation dynamically, the system optimizes transmission parameters to match instantaneous channel conditions, resolving the contradiction between adaptability and complexity

Inventive Principle:
Principle #35Parameter changes

2Reliability

If unicast mode is used for each terminal, then individual channel quality optimization is achieved, but spectral efficiency deteriorates due to redundant transmission of same data to multiple terminals

Engineering Contradiction:
Improvechannel quality adaptationVSAvoidspectral efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent merges the benefits of unicast (channel quality adaptation) with multicast (resource sharing). By determining a single set of optimized pre-coders and resource unit quantities that satisfy multiple terminals' channel conditions, the system combines unicast-level optimization with multicast efficiency, avoiding redundant transmissions while maintaining reliability

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent creates a universal transmission scheme that serves multiple terminals simultaneously with optimized pre-coders. The determined pre-coders and resource unit quantities are universally applicable to all K terminals in the multicast group, achieving channel quality adaptation for each terminal while maintaining spectral efficiency through shared resource allocation

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Productivity

If more pre-coders are used for optimization, then transmission capacity is improved, but computational complexity increases

Engineering Contradiction:
Improvetransmission capacityVSAvoidpre-coder optimization complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent segments the large set of candidate pre-coders into a manageable subset of N optimized pre-coders. By selecting and optimizing only the most relevant pre-coders for the current channel conditions rather than evaluating all possible pre-coders, the system reduces computational complexity while maintaining high transmission capacity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies partial action by determining optimized pre-coders and resource unit quantities for only the necessary number of data streams (N′≤N) rather than optimizing all possible transmissions. This selective optimization approach achieves sufficient transmission capacity while limiting computational complexity to what is truly necessary

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentUS11258488B2Method for transmitting, computer program product, and transmitter
Publication Date: 2022.02.22 MITSUBISHI ELECTRIC CORP
  • US11258488B2 patent drawing
  • US11258488B2 patent drawing
  • US11258488B2 patent drawing

AI summary

The invention relates to the transmitting of a public data to at least a number K of terminals in a wireless communication system employing a MIMO (Multiple Input Multiple Output) scheme, using a set of N pre-coders (Wi). The method includes, based on the N pre-coder (Wi), determining a set of N′≤N optimized pre-coders (W′i) and, based on the set of N′≤N optimized pre-coders (W′i), computing N′ optimized resource unit quantities T′(i), the N′ optimized pre-coders respectively corresponding to the N′ optimized resource units quantities T′(i). The method further includes transmitting N′ data Di, each of the N′ data being a part of the public data, such that, for i=1 to N′, Di is transmitted on T′(i) resource units which are pre-coded onto NTx antennas using the pre-coder W′i.