MU-MIMO Beamforming Channel Estimation via Spatial Stream Segmentation

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Solution Overview

Problem

Current wireless communication systems face challenges in performing accurate channel estimation between beamformers and beamformees, especially when the beamformee has a lower number of supported spatial streams than the beamformer, limiting the ability to achieve full array gain and efficient data transmission.

Innovation Solution

The method involves determining subsets of transmit spatial streams from the beamformer, sending sounding frames to the beamformee for channel estimation, and combining responses to generate full channel estimation information, allowing the beamformer to steer its antennas effectively even when communicating with devices of lower dimensionality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the beamformer uses all its transmit spatial streams for channel estimation, then the channel estimation accuracy is improved, but the beamformee cannot process the estimation due to its limited spatial stream capacity

Engineering Contradiction:
Improvechannel estimation accuracyVSAvoidcompatibility with beamformee
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent divides the full set of transmit spatial streams into multiple subsets, each containing a number of streams that the beamformee can process. Instead of transmitting all streams simultaneously, the beamformer segments them and transmits in separate sounding frames, allowing the beamformee to handle each subset independently while still enabling full channel estimation when results are combined.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies partial action by transmitting only a subset of the total spatial streams in each sounding frame rather than all streams at once. This allows the beamformee to process manageable portions while the beamformer ultimately achieves complete channel estimation information by aggregating results from multiple partial transmissions.

Inventive Principle:
Principle #16Partial or excessive action

2Measurement precision

If the beamformer transmits multiple sounding frames with different antenna patterns, then full channel estimation information is achieved, but the transmission time and complexity increase

Engineering Contradiction:
Improvechannel estimation information completenessVSAvoidsounding transmission time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent uses periodic action by transmitting multiple sounding frames in a structured sequence, each containing a different subset of spatial streams. The beamformer systematically cycles through different antenna patterns in separate transmissions, allowing the beamformee to process each frame independently while the beamformer aggregates the periodic results to achieve complete channel estimation.

Inventive Principle:
Principle #19Periodic action

3Power

If the beamformer configures subsets with overlapping antennas, then full array gain is achieved, but the processing complexity increases

Engineering Contradiction:
Improvearray gainVSAvoidsubset configuration complexity
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The patent applies merging by combining results from multiple sounding frames that use overlapping antenna subsets. The beamformer aggregates channel estimation information from each subset transmission, merging the partial results to construct complete channel state information for all transmit antennas, thereby achieving full array gain through combination of partial measurements.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP2911356B1Supporting high dimensional MU-MIMO beamforming by sounding multiple frames with different sets of antenna patterns
Publication Date: 2019.06.26 AVAGO TECHNOLOGIES INTERNATIONAL SALES PTE LTD
  • EP2911356B1 patent drawingFigure 1A
  • EP2911356B1 patent drawingFigure 1B
  • EP2911356B1 patent drawingFigure 1C

AI summary

In some aspects, the disclosure is directed to methods and systems for performing channel estimation between a beamformer and a beamformee. A beamformer can determine that a beamformee is configured to perform channel estimation for up to a pre-configured number of transmit spatial streams from the beamformer. The pre-configured number of transmit spatial streams can be less than a plurality of transmit spatial streams of the beamformer. The beamformer can determine a plurality of subsets of transmit spatial streams from the plurality of transmit spatial streams. The beamformer can send a plurality of sounding frames to the beamformee for channel estimation based at least on the determined plurality of subsets of transmit spatial streams.