TBS Determination for Equal Code Blocks in NR

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Solution Overview

Problem

The existing LTE transport block size (TBS) determination method is inefficient for flexible slot structures in NR, leading to sub-optimal code rates and reduced data throughput due to mismatched radio resource assumptions, and the use of formulas for TBS determination does not guarantee equal-sized code blocks, complicating implementation.

Innovation Solution

A modified formula for determining TBS that ensures equal-sized code blocks by adjusting the TBS calculation based on CRC bits and code blocks, eliminating the need for zero padding, thereby simplifying encoder and decoder implementation and optimizing resource use.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the existing LTE TBS determination method is used, then the calculation is simple, but the code blocks are not equal sized and implementation is complicated

Engineering Contradiction:

Improvecode block size equalityVSAvoidencoder implementation complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent modifies the TBS determination formula by changing the parameter calculation to account for CRC bits and code block segmentation. The new formula TBS = C × max(ceil((TBS0 + L1) / C), A) × A adjusts parameters to ensure equal code block sizes while maintaining computational simplicity, directly resolving the contradiction between precision and complexity.

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If zero padding is used to achieve equal size code blocks, then code blocks are equal sized, but resource efficiency is reduced

Engineering Contradiction:

Improvecode block size equalityVSAvoiddata throughput

Core Design Contradiction:

Manufacturing precisionVSLoss of substance

Solution Approach 1:

The patent applies preliminary action by determining the correct TBS value before code block segmentation using the modified formula. This ensures that the transport block is sized appropriately from the outset to divide into equal code blocks without requiring subsequent zero padding, thus maintaining resource efficiency while achieving code block equality.

Inventive Principle:

Principle #10Preliminary action

3Ease of operation

If the existing TBS formula is used, then calculation is straightforward, but radio resource assumptions are mismatched and throughput is reduced

Engineering Contradiction:

ImproveTBS calculation simplicityVSAvoiddata throughput

Core Design Contradiction:

Ease of operationVSProductivity

Solution Approach 1:

The patent changes the parameters in the TBS determination formula to include C (number of code blocks), L1 (CRC bits), and A (minimum code block size). This modified parameter set aligns the calculation with actual radio resource assumptions and code block segmentation requirements, improving throughput while keeping the calculation straightforward through the systematic formula structure.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentEP3665803B1Transport block size determination for equal size code blocks

Publication Date: 2025.10.08 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

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AI summary

According to some embodiments, a method for use in a wireless receiver comprises determining a transport block size, TBS, for a transport block to be communicated between the wireless transmitter and a wireless receiver via a physical channel transmission. The TBS determination uses a formula accounting for cyclic redundancy check, CRC, bits. The method further comprises transmitting the transport block according to the determined TBS. In particular embodiments the formula is based on an approximate transport block size, a number of code blocks, at least one of a number of CRC bits attached to the transport block, and a number of CRC bits added to each of the C code blocks.