MIMO Precoding Codebook Segmentation for Channel Feedback

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Solution Overview

Problem

Current MIMO communication systems face challenges in accurately determining optimal precoding matrices for data transmission, particularly in managing channel quality and direction information, which affects data stream performance and channel utilization.

Innovation Solution

The use of two codebooks, one for wideband/long-term channel information and another for subband/short-term information, allows the transmitter to generate an optimal precoding matrix by combining indicators from both, enhancing data stream transmission efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single codebook is used for precoding matrix selection, then device complexity is reduced, but measurement precision of channel information deteriorates

Engineering Contradiction:

Improvecodebook management complexityVSAvoidchannel information accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The codebook is segmented into two distinct codebooks: a first codebook for wideband/long-term channel information and a second codebook for subband/short-term channel information. This segmentation allows each codebook to specialize in specific temporal and spectral domains, improving the precision of channel information representation while managing complexity through structured division.

Inventive Principle:

Principle #1Segmentation

2Measurement precision

If two codebooks are used for precoding matrix selection, then measurement precision of channel information is improved, but device complexity increases

Engineering Contradiction:

Improvechannel information accuracyVSAvoidcodebook management complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system dynamically selects and combines precoding matrices from different codebooks based on channel conditions. The transmitter and receiver adaptively choose which codebook to use for specific feedback scenarios, allowing the system to optimize between precision and complexity dynamically rather than being fixed in one configuration.

Inventive Principle:

Principle #15Dynamics

3Productivity

If codebook feedback is used for MIMO communication, then data transmission rate is improved, but loss of information in channel feedback increases

Engineering Contradiction:

Improvedata transmission rateVSAvoidchannel feedback information loss

Core Design Contradiction:

ProductivityVSLoss of information

Solution Approach 1:

Channel feedback information is segmented into different components: wideband/long-term channel information from the first codebook and subband/short-term channel information from the second codebook. This segmentation ensures that critical long-term channel characteristics are preserved while allowing flexible short-term adaptations, reducing information loss in the feedback loop.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The first codebook provides preliminary wideband/long-term channel information that establishes a baseline for precoding. This preliminary action allows the second codebook to focus on finer subband adjustments, ensuring that essential channel information is captured beforehand and reducing the risk of information loss during feedback transmission.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentEP3920427B1Multiple input multiple output communication system using codebook corresponding to each reporting mode

Publication Date: 2024.06.26 SAMSUNG ELECTRONICS CO LTD

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AI summary

A communication method of a receiver in a wireless communication system, the communication method comprising obtaining a rank indicator; obtaining a first precoding matrix indicator based on the rank indicator; obtaining a second precoding matrix indicator associated with the first precoding matrix indicator; when the rank indicator is 1, transmitting the rank indicator, and transmitting the first precoding matrix indicator obtained based on a subset of a first codebook, the second precoding matrix indicator and a wideband channel quality index (CQI); and when the rank indicator is 2, transmitting the rank indicator, and transmitting the first precoding matrix indicator obtained based on a subset {0, 2, 4, 6, 8, 10, 12, 14} of the first codebook, the second precoding matrix indicator and a wideband channel quality index(CQI), wherein when the rank indicator is 1 or 2, the first precoding matrix indicator is 3 bits, and the second precoding matrix indicator is 1 bit.