Cooperative HARQ Retransmission on a Second Channel
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Inter cell interference and high feedback overhead in cooperative antenna systems, as well as performance degradation due to retransmissions in communication networks, particularly in FDD systems and LTE networks, limit the efficiency of data transmission.
Innovation Solution
A method and system for transmitting data using a cooperative transmission scheme on a first channel, with retransmissions occurring on a second channel that is different from the first, potentially orthogonal or non-cooperative, to reduce delay and interference, and optimize Hybrid Automatic Repeat Request (HARQ) processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If cooperative transmission scheme is used on the same channel for retransmission, then channel resource utilization is improved, but inter cell interference increases and transmission reliability deteriorates
Solution Approach 1:
The patent segments the transmission process into two distinct parts: initial transmission on a first channel and retransmission on a second channel. This segmentation allows each transmission phase to use optimized channel resources, preventing interference while ensuring reliable delivery. The receiver can selectively combine successful initial transmissions with retransmissions, improving overall reliability without compromising resource utilization.
Solution Approach 2:
The patent introduces an intermediary mechanism (the second channel) that mediates between the conflicting requirements of resource efficiency and transmission reliability. By using a different channel for retransmissions, the system avoids direct interference with ongoing cooperative transmissions on the first channel, while still providing a dedicated path for error correction and retransmission.
2Loss of information
If retransmissions are performed on the same cooperative channel, then feedback overhead is reduced, but system performance deteriorates due to interference
Solution Approach 1:
The patent segments feedback channels into two types: feedback for initial transmissions on the first channel and feedback for retransmissions on the second channel. This segmentation allows the system to maintain low feedback overhead for successful transmissions while providing a separate, interference-free path for retransmission feedback, thereby preserving system performance.
Solution Approach 2:
The patent applies partial action by using the second channel only for retransmissions rather than all transmissions. This selective approach minimizes the impact on overall system performance while still providing the necessary feedback mechanism for error correction, balancing feedback overhead with performance requirements.
3Reliability
If HARQ retransmissions are implemented in cooperative antenna systems, then transmission reliability is improved, but delay increases
Solution Approach 1:
The patent prepares the second channel in advance as a dedicated retransmission path, so that when retransmissions are needed, they can occur immediately without channel negotiation or setup delays. This preliminary preparation of alternative channel resources significantly reduces the time penalty associated with HARQ retransmissions while maintaining high reliability.
Data Source
AI summary
A method of transmitting data in a communication network is provided, wherein the method includes sending an error message indicating that a data packet transmitted using a cooperative transmission scheme on a first channel is not decoded correctly, and retransmitting the data packet using a second channel which is different from the first channel.