CSI Quantization Using Single-Cell Codebooks for Dynamic MIMO

Solution Overview

Problem

In a cooperative MIMO system, the dynamic change in the number of cooperative base stations makes it impossible to set a codebook for quantizing channel state information (CSI) between the mobile station and base stations, preventing the transmission of CSI information.

Innovation Solution

The method involves acquiring CSI information between a mobile terminal and multiple cooperative base stations, quantizing it using a preset single-cell codebook for each base station, and transmitting united codeword indexes, allowing the base stations to look up the CSI information from the codebooks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a codebook is preset for quantizing CSI information between MS and BS, then CSI transmission is enabled in single-cell MIMO systems, but this approach becomes inapplicable when the number of cooperative BSs changes dynamically in cooperative MIMO systems

Engineering Contradiction:

Improveadaptability to dynamic cooperative BS configurationVSAvoidcodebook management complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the cooperative MIMO system into multiple single-cell MIMO sub-systems, each with its own preset codebook. Instead of creating one complex codebook for the entire cooperative system, the method divides the CSI quantization task across multiple independent single-cell codebooks, one for each cooperative base station pair with the mobile station. This segmentation allows the system to adapt to dynamic changes in the number of cooperative BSs while maintaining the simplicity of preset codebooks.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent makes single-cell codebooks universal by designing them to work across different cooperative MIMO configurations. The same single-cell codebook structure can be reused for any number of cooperative base stations, making the codebook design independent of the specific system configuration. This universality allows the system to adapt to dynamic changes without requiring redesign of the codebook structure.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If complete CSI information is transmitted from MS to BS, then the BS can perform accurate communication, but the limited number of coded bits prevents transmission of complete CSI information

Engineering Contradiction:

Improvecommunication accuracyVSAvoidCSI information loss

Core Design Contradiction:

ReliabilityVSLoss of information

Solution Approach 1:

The patent extracts only the essential CSI information needed for communication by quantizing the complete CSI using preset codebooks. Instead of transmitting the full CSI matrix, the method extracts the most important channel state characteristics that can be represented within the limited codebook entries, achieving a balance between information completeness and transmission constraints.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent transforms the continuous CSI information into discrete quantized values by mapping channel state parameters to codebook indices. This parameter transformation converts the infinite-precision CSI into a finite set of representable values that can be transmitted within the limited number of coded bits, while preserving the essential communication information.

Inventive Principle:

Principle #35Parameter changes

3Ease of operation

If quantization of CSI information is performed using preset codebooks, then limited CSI can be transmitted within bit constraints, but no codebook can be set for cooperative MIMO systems with dynamically changing BS numbers

Engineering Contradiction:

ImproveCSI transmission feasibilityVSAvoidcodebook applicability to dynamic configurations

Core Design Contradiction:

Ease of operationVSAdaptability or versatility

Solution Approach 1:

The patent segments the cooperative MIMO system into multiple single-cell MIMO sub-systems, each with its own preset codebook. Instead of creating one complex codebook for the entire cooperative system, the method divides the CSI quantization task across multiple independent single-cell codebooks, one for each cooperative base station pair with the mobile station. This segmentation allows the system to adapt to dynamic changes in the number of cooperative BSs while maintaining the simplicity of preset codebooks.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces dynamics into the codebook selection process by allowing the mobile station to select and use appropriate single-cell codebooks based on the current number of cooperative base stations. The system dynamically adapts to configuration changes by activating or deactivating specific codebook instances, enabling seamless operation as BSs are added or removed from the cooperative set.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS8750150B2Method, apparatus and system for transmitting channel state information

Publication Date: 2014.06.10 HUAWEI TECH CO LTD

AI summary

An apparatus and a system for transmitting channel state information acquires channel state information of a channel between a mobile terminal and two or more cooperative base stations. The apparatus quantizes the channel state information separately by using a preset single-cell codebook used for quantizing the channel between the mobile terminal and each one of the two or more cooperative base stations. The apparatus acquires united codeword indexes of the quantized channel state information in the single-cell codebook; and transmits the united codeword indexes of the quantized channel state information in the single-cell codebook.