Code Block Reordering for HARQ Retransmissions
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Solution Overview
Problem
Wireless communication systems face performance degradation due to time invariant impairments such as spurs, periodic interference, and residual frequency impairment during HARQ communications, leading to reduced processing gain and increased retransmissions, which consume network resources.
Innovation Solution
Implementing code block reordering for HARQ communications based on feedback from receiver devices to vary which code blocks experience impairments, thereby increasing the average processing gain and reducing the likelihood of dropped communications by optimizing the retransmission strategy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If code blocks are transmitted in a fixed order during HARQ retransmissions, then the transmission process is simple and deterministic, but time invariant impairments such as spurs and periodic interference cause degraded performance for specific code blocks, reducing processing gain
Solution Approach 1:
The patent applies dynamics by changing the code block transmission order dynamically based on the retransmission type. For initial transmissions, code blocks are sent in sequential order (0, 1, 2, 3...). For retransmissions, the order is permuted using a mathematical function that depends on the retransmission index, creating a dynamic transmission strategy that adapts to different transmission scenarios and avoids fixed pattern impairments.
Solution Approach 2:
The patent changes the transmission parameter of code block ordering by introducing a permutation function that varies with the retransmission index. The code block index is transformed using the function f(cb_index, retransmission_index) to determine the new transmission order, effectively changing how code blocks are sequenced based on the transmission context to mitigate time invariant impairments.
2Reliability
If code block reordering is implemented for retransmissions, then average processing gain increases and dropped communications are reduced, but the system complexity and feedback processing requirements increase
Solution Approach 1:
The patent implements feedback mechanisms where the receiver device sends feedback information to the transmitter about the reception status of code blocks. This feedback triggers the retransmission process and enables the transmitter to determine which code blocks need retransmission, creating a closed-loop system that improves reliability while managing complexity through information exchange between transmitter and receiver.
Solution Approach 2:
The patent segments the code blocks into different transmission groups based on their original positions and applies different permutation strategies. By dividing the code block reordering problem into manageable segments that can be independently permuted and retransmitted, the system handles complexity in a structured way while maintaining overall communication reliability.
Data Source
AI summary
Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a transmitter device may transmit a hybrid automatic repeat request (HARQ) communication using a first code block order for code blocks of the HARQ communication; detect a trigger to retransmit the HARQ communication based at least in part on transmitting the HARQ communication; reorder the code blocks of the HARQ communication based at least in part on detecting the trigger to retransmit the HARQ communication; and retransmit the HARQ communication using a second code block order based at least in part on reordering the code blocks of the HARQ communication. Numerous other aspects are provided.