Outer Coding with Cyclic Shift Parity for TB Retransmission
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Solution Overview
Problem
Current wireless communication systems face challenges in reducing the amount of resources needed for retransmitting data that was not successfully decoded, particularly in scenarios where bursty interference from coexisting usage scenarios like eMBB and URLLC leads to decoding failures, even at high signal-to-noise ratios.
Innovation Solution
The method involves transmitting a transport block (TB) with a first parity check code block and receiving feedback on decoding failures, followed by generating and transmitting a second parity check code block using a cyclic shift parity check scheme, which is different from the first, to enable efficient error detection and correction without requiring advance knowledge of the number of failed code blocks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If H-ARQ retransmission is used with TB-based scheduling, then the complexity of network devices is reduced by limiting the number of concurrent H-ARQ processes, but the amount of resources needed for retransmission increases when decoding of any FEC block within a TB fails
Solution Approach 1:
The transport block (TB) is segmented into multiple code blocks (CBs), each with its own CRC check. This allows the system to identify and retransmit only the specific failed CBs rather than retransmitting the entire TB, thereby reducing the quantity of resources needed for retransmission while maintaining TB-based scheduling and limiting H-ARQ process complexity.
2Reliability
If redundant versions of all FEC blocks are retransmitted upon decoding failure of one block, then error correction capability is maintained, but resource efficiency decreases
Solution Approach 1:
The system extracts and identifies only the specific failed code blocks using individual CRC checks for each CB. Instead of retransmitting all redundant versions of all FEC blocks, the system extracts and retransmits only the necessary failed CBs, thereby maintaining error correction capability while improving resource efficiency.
3Adaptability or versatility
If bursty interference from coexisting usage scenarios is present, then system capacity for multiple services is achieved, but decoding failure rate increases even at high SNR
Solution Approach 1:
The system uses feedback from CRC checks on each code block to identify which specific CBs failed decoding. This feedback mechanism allows the system to adapt to bursty interference by precisely identifying and retransmitting only the affected CBs, thereby maintaining high decoding success rates even in mixed eMBB and URLLC scenarios.
Data Source
Figure 1
Figure 2A~2B
Figure 3A
AI summary
Embodiments relate to outer coding in communications between a first network device and a second network device. A transport block (TB) and a first parity code block that is based on contents of the TB are transmitted from the first network device to the second network device. The first network device receives feedback information that is transmitted from the second network device. The feedback information indicates a decoding failure of the TB. The first network device generates a second parity check CB that is based on the contents of the TB and is different from the first parity check CB and transmits the second parity check CB to the second network device. The second network device receives the second parity check CB and performs error detection decoding of the TB based on the second parity check CB.