MIRS Retransmission Optimization for Groupcast Using Network Coding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wireless communication systems face challenges in optimizing re-transmissions for groupcast mode, particularly in reducing the number of retransmitted code blocks while maintaining communication at or near capacity code rate.
Innovation Solution
The use of multi incremental redundancy scheme (MIRS) techniques combined with network coding techniques at a base station to determine candidate retransmission vectors and combine them using specific rules, thereby reducing the total number of retransmission messages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional retransmission methods are used for groupcast, then communication reliability is maintained, but the number of retransmitted code blocks increases and resource consumption increases
Solution Approach 1:
The patent combines network coding with incremental redundancy (IR-HARQ) to create a hybrid retransmission scheme. The base station encodes retransmission candidates using network coding operations (XOR) and transmits them to multiple UEs simultaneously. This merging allows a single retransmission message to serve multiple UEs with different decoding needs, reducing the total number of retransmitted code blocks while maintaining communication reliability.
Solution Approach 2:
The base station performs preliminary actions by encoding retransmission candidates before actual retransmission occurs. The system pre-determines which code blocks need retransmission based on NACK feedback and prepares encoded versions in advance. This preliminary encoding and preparation enables more efficient retransmission delivery, reducing the number of retransmission messages needed.
2Reliability
If more retransmission messages are sent to ensure reliable delivery, then communication reliability improves, but signaling overhead and processing power increase
Solution Approach 1:
Multiple retransmission messages are merged into a single network-coded retransmission message that can be simultaneously delivered to multiple UEs. The base station combines retransmission candidates for different UEs using network coding operations, creating one consolidated message that reduces signaling overhead while maintaining the reliability needed for each individual UE's communication.
Solution Approach 2:
The retransmission message is designed with universality to serve multiple functions simultaneously. A single retransmission message can be received and processed by multiple UEs, each extracting the information they need based on their individual decoding requirements. This multi-functional approach reduces the total number of messages required, thereby reducing signaling overhead and processing power consumption.
Data Source
AI summary
Methods, systems, and devices for wireless communications are described. A base station may transmit a set of code blocks to multiple user equipments (UEs). The base station may receive feedback pertaining to reception of each of the set of code blocks at each of the multiple UEs. The base station may generate, based on the feedback, a retransmission message that includes encoded data representative of a subset of code blocks of the set of code blocks and additional redundancy with respect to the subset of code blocks. The multiple UEs may receive the retransmission message and extract a portion corresponding the set of code blocks that were previously unsuccessfully decoded. The UEs may combine the portion of the set of code blocks with the unsuccessfully decoded code blocks to create an updated combined versions of the code blocks. The UEs may decode the combined versions of the code blocks.