HARQ Redundancy Version Selection for Low-Overhead Packet Decoding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In communication systems like E-DCH, ensuring that retransmitted data packets can be correctly combined with initial packets for decoding is challenging, especially during soft handover and when the receiver misses packets due to interference, leading to excessive signaling overhead from Retransmission Sequence Numbers (RSN).
Innovation Solution
The method involves transforming data packets into different redundancy versions for retransmissions based on coding parameters, allowing for self-decodable versions and reducing RSN value range, thereby improving decoding efficiency with minimal additional signaling effort.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If Retransmission Sequence Number (RSN) is used to ensure correct packet combination, then packet combination accuracy is improved, but signaling overhead increases excessively
Solution Approach 1:
The patent extracts the essential function of RSN (identifying retransmission packets) and separates it from the full RSN value transmission. Only the necessary portion (new data indicator bit) is transmitted explicitly, while the rest is derived implicitly at the receiver side, reducing signaling overhead while maintaining packet combination accuracy
Solution Approach 2:
The receiver reconstructs the RSN value locally by copying/deriving it from the transmitted new data indicator bit and its own internal counter, eliminating the need to transmit the full RSN value and reducing signaling overhead
2Reliability
If maximum number of retransmissions is supported, then reliability is improved, but RSN value range increases causing excessive signaling
Solution Approach 1:
The patent applies partial action by transmitting only the necessary portion of RSN information (the new data indicator bit that indicates whether the packet is a new transmission or retransmission) rather than the full RSN value, supporting maximum retransmissions with minimal signaling
Solution Approach 2:
Instead of transmitting the RSN value directly from the transmitter, the system inverts the approach by having the receiver derive the RSN value from the transmitted new data indicator bit and its own counter, reducing the signaling burden
3Speed
If synchronous retransmission protocol is used, then packet timing is improved, but ability to identify same-packet retransmissions during soft handover deteriorates
Solution Approach 1:
The patent uses feedback through the new data indicator bit that provides explicit information to the receiver about whether a packet is new or a retransmission, enabling accurate packet identification during soft handover while maintaining synchronous retransmission timing
Solution Approach 2:
The new data indicator bit acts as an intermediary that carries the essential identification information between transmitter and receiver, enabling accurate packet matching during soft handover without requiring complex timing analysis
Data Source
AI summary
A decoding method for decoding information content in at least one data packet, which is transmitted from a sender to a receiver via a data link. The information is represented by a bit sequence, which is transformed into a transmittable redundancy version. The information is initially transmitted for a first time in a first data packet from the sender to the receiver. The information is represented by a first redundancy version, which is self-decodable. An incorrect receipt is confirmed by sending a confirmation from the receiver to the sender. The information is retransmitted at least a second time in a second data packet from the sender to the receiver upon receipt of the confirmation, wherein, for representation of the information, a second redundancy version is used, the selection of which is performed in dependence on a coding parameter, describing whether the redundancy version is self-decodable or not.