Joint TBS and Redundant Version Index for Wireless Data Encoding

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Solution Overview

Problem

Current wireless communication systems, such as LTE and proposed 5G standards, face challenges in fully utilizing bits for encoding Transport Block Size (TBS) and modulation order, leading to magnified quantization errors and inability to support different channel qualities among layers, resulting in inefficient data transmission and throughput issues.

Innovation Solution

A joint coding scheme combining the 5 bits for indicating the TBS Index and 2 bits for indicating the Redundant Version into a single 7-bit index, along with a differential coding scheme for modulation orders, allows for increased TBS levels and channel diversity without increasing the DCI size, enabling independent TBS and modulation decisions for any PRB number.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If separate encoding of TBS index and redundant version is used, then decoding is straightforward, but quantization errors are magnified and TBS levels are limited

Engineering Contradiction:
Improvequantization errorVSAvoidcoding scheme complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines the 5-bit TBS index and 2-bit redundant version into a single 7-bit joint index. This merging increases the number of available TBS levels from 32 to 128, thereby reducing quantization errors while maintaining a manageable coding complexity through a unified lookup table approach.

Inventive Principle:
Principle #5Merging (Combining)

2Adaptability or versatility

If joint coding of TBS and modulation is used, then flexibility is improved, but constraints are introduced that limit independent optimization

Engineering Contradiction:
ImproveTBS and modulation flexibilityVSAvoidconstraint complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the joint index space into distinct regions: one region for indicating TBS and modulation combinations, and another region for indicating redundant versions. This segmentation allows independent optimization of TBS and modulation parameters while maintaining the benefits of joint coding flexibility.

Inventive Principle:
Principle #1Segmentation

3Measurement precision

If DCI size is increased to support more TBS levels and channel diversity, then quantization precision is improved, but overhead increases

Engineering Contradiction:
ImproveTBS indication precisionVSAvoidDCI size
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent merges the TBS index and redundant version into a single 7-bit joint index, achieving 128 TBS levels without increasing the DCI size. This combining approach provides high precision TBS indication while maintaining efficient spectral overhead.

Inventive Principle:
Principle #5Merging (Combining)

4Ease of operation

If all layers use the same modulation order, then decoding is simplified, but channel diversity among layers is not supported

Engineering Contradiction:
Improvedecoding simplicityVSAvoidchannel diversity support
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The patent enables different modulation orders for different groups of layers by utilizing specific regions of the joint index space. This local quality approach allows each layer group to be optimized for its specific channel conditions while maintaining overall system simplicity through a unified indexing mechanism.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3639424B1Method and node for decoding or encoding user data based on a joint TBS index and redundant version
Publication Date: 2022.09.14 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3639424B1 patent drawingFigure 1
  • EP3639424B1 patent drawingFigure 2~3
  • EP3639424B1 patent drawingFigure 4~5

AI summary

There is provided a method performed by a wireless device for handling user data, wherein the user data are converted into codewords, each codeword having a first group of layers and a second group of layers. The method comprises: receiving an index from a network node, the index indicating a Transport Block Size (TBS) index, a Redundant Version (RV) and a differential modulation; determining a TBS based on the received index; determining a redundant version value based on the received index; determining a first modulation order for the first group and a second modulation order for the second group of a codeword, based on the differential modulation; and performing one of decoding and encoding the codeword based at least on the determined first and second modulation orders, the determined TBS and the determined redundant version value.