Aligned HARQ Frame Structure for Selective Data Retransmission
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Solution Overview
Problem
Existing wireless communication systems face inefficiencies in power consumption, throughput, computational complexity, and end-to-end delay due to the integration of forward error correction (FEC) and automatic repeat request (ARQ) protocols, particularly in handling noise, interference, and channel fading, leading to misalignment issues in HARQ protocols.
Innovation Solution
A method for transmitting data units by segmenting them into multiple parts, aligning Medium Access Control (MAC) protocol data units (MPDUs) and Forward Error Correction (FEC) units, and encoding them into codewords, followed by retransmitting parts based on negative acknowledgments to ensure aligned boundaries across layers, facilitating efficient HARQ processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If FEC and ARQ protocols are integrated to correct data errors, then reliability is improved, but power consumption and computational complexity increase
Solution Approach 1:
The data unit is segmented into multiple parts, and each part is further segmented into MPDUs and FEC units. This segmentation allows selective retransmission of only the problematic parts rather than the entire data unit, reducing the computational load and power consumption associated with processing and retransmitting unnecessary data while maintaining reliable error correction.
Solution Approach 2:
The patent implements a feedback mechanism where the receiver sends negative acknowledgments (NACKs) for specific parts that failed to decode successfully. This targeted feedback allows the transmitter to retransmit only the problematic parts, avoiding the need to retransmit the entire data unit and thereby reducing overall power consumption and processing complexity.
2Reliability
If FEC and ARQ protocols are integrated to correct data errors, then reliability is improved, but throughput is reduced
Solution Approach 1:
By dividing the data unit into parts with aligned boundaries at MAC and physical layers, the system enables parallel processing and selective retransmission. This segmentation maintains throughput by allowing successful parts to be processed while only problematic parts are retransmitted, preventing throughput degradation from full-unit retransmissions.
Solution Approach 2:
Instead of requiring full retransmission of the entire data unit upon error detection, the patent applies partial retransmission of only the affected parts. This partial action approach maintains higher throughput by minimizing the amount of data that needs to be retransmitted and processed, while still ensuring complete error correction.
3Reliability
If FEC and ARQ protocols are integrated to correct data errors, then reliability is improved, but end-to-end delay increases
Solution Approach 1:
The data unit is pre-segmented into parts with aligned boundaries before transmission. This preliminary segmentation allows the receiver to quickly identify and request retransmission of only the problematic parts, reducing the time required for error correction compared to full-unit retransmission protocols.
Solution Approach 2:
The targeted feedback mechanism for specific parts enables faster error correction by allowing the transmitter to immediately retransmit only the problematic parts upon receiving a NACK, rather than waiting for and processing the entire data unit again, thereby reducing end-to-end delay.
4Productivity
If data units are segmented into parts with aligned MPDUs and FEC units, then HARQ processing efficiency is improved, but device complexity increases
Solution Approach 1:
The data unit is divided into parts with aligned boundaries at both MAC and physical layers. This alignment simplifies the HARQ processing structure by ensuring that retransmitted parts maintain consistent boundaries across layers, making the processing more efficient despite the increased segmentation.
Solution Approach 2:
The aligned boundary structure serves multiple functions simultaneously: it enables efficient HARQ processing, ensures proper FEC encoding boundaries, and facilitates synchronized retransmission. This multi-functionality reduces the need for separate processing mechanisms, thereby managing device complexity while improving processing efficiency.
Data Source
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AI summary
The present disclosure provides methods and apparatuses for receiving and transmitting data over a wireless interface. A data unit is transmitted and/or received split into a plurality of parts. The parts may be used as redundancy versions that are transmitted if retransmission is necessary. In particular, each part is segmented into an integer number of MPDUs and the MPDUs are segmented into FEC units that become codewords after FEC encoding. If the transmission of the entire data unit is not successful, the redundancy versions corresponding to the parts are transmitted in a predefined order. Alternatively, those redundancy versions may be transmitted which were identified as erroneous (not successfully decodable).