Adaptive Code Block Retransmission in Multicarrier Mobile Links
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Solution Overview
Problem
The multicarrier mobile communication system faces inefficiencies in retransmissions due to a constant iteration pattern, leading to suboptimal retransmission efficiency, especially when error rates in code words are low, as the same size of transmission signal is retransmitted regardless of error distribution.
Innovation Solution
The system introduces a mechanism where iterative decoding is terminated early for code blocks with no errors and resources are dynamically reassigned based on error detection, allowing for flexible retransmission by reducing the size of code blocks with few errors and increasing resources for those with more errors, using feedback data to adjust resource allocation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a constant iteration pattern is used for retransmission scheduling, then the scheduling is simple and systematic, but the retransmission efficiency deteriorates when error rates are low
Solution Approach 1:
The patent applies dynamics by making the iteration pattern adaptive rather than constant. The receiving apparatus determines the number of iteration executions based on the actual error correction decoding requirements of each code block. When few errors are present, iteration is terminated early; when many errors exist, iteration continues longer. This dynamic adjustment optimizes retransmission efficiency while maintaining systematic scheduling through feedback-based control.
2Stability of the object's composition
If retransmission occurs in fixed units of CRC additional units, then the retransmission scheduling is consistent, but the retransmission efficiency worsens when error inclusion rate is low
Solution Approach 1:
The patent applies local quality by treating different code blocks differently based on their individual error characteristics. Instead of applying a uniform retransmission unit size to all code blocks, the receiving apparatus evaluates each code block's error correction decoding results and determines the appropriate number of iteration executions for each block. This localized adaptation allows efficient resource utilization by matching retransmission effort to actual error conditions in each code block.
Solution Approach 2:
The patent changes the parameter of iteration execution count from a fixed constant to a variable determined by decoding performance. The receiving apparatus monitors the error correction decoding results and dynamically adjusts the number of iteration executions for each code block. This parameter change enables the system to reduce unnecessary iterations when errors are few while maintaining sufficient iterations when errors are numerous, thereby improving overall retransmission efficiency.
3Ease of operation
If the same size retransmission is performed regardless of error distribution, then the scheduling is straightforward, but the system throughput deteriorates due to inefficient resource usage
Solution Approach 1:
The patent implements feedback by having the receiving apparatus monitor error correction decoding results and communicate the required number of iteration executions back to the transmitting apparatus. This feedback mechanism enables the system to adjust retransmission resource allocation based on actual channel conditions and error distributions. The transmitting apparatus uses this feedback to optimize resource allocation, allocating more resources to code blocks requiring extensive iteration and fewer resources to those needing minimal correction, thereby improving system throughput while maintaining manageable scheduling complexity.
Data Source
AI summary
A transmitting unit divides a transmit data into a plurality of code blocks, and encodes each of the plurality of code blocks to generate a transmission signal. The transmitting unit transmits the transmission signal, and a receiving unit receives the transmission signal as a reception signal. The receiving unit receives performs an iterative decoding to each of the plurality of code blocks of the reception signal. The iterative decoding is terminated to a first code block group in which an error has not been detected before a first setting iteration count. The receiving unit, when being an error in the reception signal, transmits a retransmission request feedback data which contains a NACK data and a data indicating the first code block group to the transmitting unit. First resources are assigned for each of the plurality of code blocks of the transmission signal. The transmitting unit assigns resources of the first code block group of the plurality of code blocks of the transmission signal to second resources which are fewer than the first resources, based on the retransmission request feedback data, and retransmits the transmission signal to the receiving unit.