Distributed MIMO Codebook for RRH Selection

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Solution Overview

Problem

Current wireless communication systems face challenges in accurately estimating the channel state information (CSI) between user equipment (UE) and base stations (BS) in distributed MIMO transmission, particularly with multiple remote radio heads (RRHs), leading to inefficiencies in data communication.

Innovation Solution

The implementation of a method where a UE selects and reports the strongest RRH from multiple RRHs, using a codebook-based CSI reporting mechanism to enhance CSI reporting accuracy and efficiency in distributed MIMO systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If distributed MIMO transmission with multiple RRHs is used, then coverage and capacity are improved, but channel estimation accuracy deteriorates

Engineering Contradiction:

Improvedata communication capacityVSAvoidchannel estimation accuracy

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The patent segments the distributed RRHs into distinct groups, with each RRH transmitting separate CSI-RS reference signals. The UE measures and reports CSI for each RRH group independently, allowing the system to maintain accurate channel estimation for each segment while benefiting from the overall distributed MIMO capacity and coverage improvements

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces CSI reporting as an intermediary mechanism between the UE and gNB. The UE measures channel state information from multiple RRHs and reports back to the gNB, which then uses this feedback to select appropriate communication parameters. This intermediary feedback loop enables accurate channel estimation despite the complexity of distributed MIMO transmission

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If CSI reporting for multiple RRHs is performed, then communication parameter selection is improved, but feedback overhead increases

Engineering Contradiction:

Improvecommunication parameter selection accuracyVSAvoidfeedback overhead

Core Design Contradiction:

ReliabilityVSLoss of information

Solution Approach 1:

The patent implements partial action by having the UE report CSI for each RRH group separately rather than providing complete CSI for all RRHs simultaneously. This selective reporting approach maintains sufficient accuracy for parameter selection while reducing the overall feedback overhead compared to reporting all possible channel state information

Inventive Principle:

Principle #16Partial or excessive action

Solution Approach 2:

The patent changes the reporting parameters by using standardized CSI reporting formats and metrics. Instead of transmitting raw channel matrices, the system uses compressed CSI representations with specific parameters (such as CQI, PMI, RI) that convey essential channel information while significantly reducing feedback overhead

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS20220190897A1Codebook for distributed MIMO transmission

Publication Date: 2022.06.16 SAMSUNG ELECTRONICS CO LTD

AI summary

A method for operating a user equipment (UE) comprises receiving information about a channel state information (C SI) report, the information including a number NRRH>1 and RRH r, wherein: NRRH=number of remote radio heads (RRHs), RRH r comprises a group of P channel state information reference signal (C SIRS) antenna ports, and r=1, . . . , NRRH; selecting a strongest RRH from the NRRH RRHs; determining the CSI report including an indicator indicating the strongest RRH; and transmitting the CSI report including the indicator indicating the strongest RRH.