PDSCH Overlap Cancellation for Downlink Feedback Reliability
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Solution Overview
Problem
In the context of 5G mobile communication systems, the issue arises when multiple PDSCHs overlap in time domain, leading to incomplete reception of downlink data by terminal devices. This results in failed feedback information, increased retransmission probability, and reduced data transmission efficiency.
Innovation Solution
The proposed solution involves a method where a network device selects non-overlapping M PDSCHs from a set of P PDSCHs and sends data only on these M PDSCHs. The terminal device receives data only on the selected M PDSCHs and sends feedback information accordingly. This approach ensures that feedback is sent even if the last repeated PDSCH is not received, thereby reducing retransmission probability and improving efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple PDSCHs are transmitted in a time unit to ensure ultra-high reliability and low latency, then data transmission reliability is improved, but terminal device reception capability is exceeded leading to feedback failure
Solution Approach 1:
The patent segments the PDSCH transmissions into two categories: those that the terminal device can successfully receive and decode, and those that exceed the terminal's reception capability. By identifying and excluding the overlapping PDSCH that causes reception failure, the system maintains reliable data transmission through alternative paths while respecting terminal device limitations.
Solution Approach 2:
Instead of having the terminal device attempt to receive all transmitted PDSCHs and fail when overwhelmed, the patent inverts the approach by having the network device proactively identify and exclude the problematic overlapping PDSCH from transmission. This prevents feedback failure before it occurs, maintaining both reliability and terminal device operability.
2Quantity of substance
If the terminal device attempts to receive all PDSCHs including overlapping ones, then data reception completeness is improved, but feedback information fails to be sent
Solution Approach 1:
The patent applies preliminary action by having the network device identify and exclude the overlapping PDSCH that would cause terminal device reception failure before transmission occurs. This prevents the terminal device from entering a state where it cannot send feedback, ensuring both complete data reception and successful feedback transmission.
Solution Approach 2:
The patent establishes a feedback mechanism where the terminal device sends acknowledgment information for successfully received PDSCHs. By ensuring the terminal device can successfully receive and process at least one PDSCH (the non-overlapping one), the system enables the feedback loop to function properly, preventing loss of feedback information.
3Quantity of substance
If overlapping PDSCHs are transmitted to increase data transmission amount, then data transmission capacity is improved, but retransmission probability increases
Solution Approach 1:
The patent extracts and removes the problematic overlapping PDSCH from the transmission set, keeping only the non-overlapping PDSCH that the terminal device can successfully receive. This eliminates the source of retransmission while maintaining data transmission capacity through the remaining valid PDSCH transmissions.
Data Source
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AI summary
This application discloses a downlink data sending method, a downlink data receiving method, and an apparatus, and relates to the communication field, to resolve a problem that feedback information fails to be sent, and consequently, a retransmission probability of downlink data is increased, and data transmission efficiency is reduced. When at least two of P PDSCHs in one slot overlap in time domain, a network device cancels sending of partially overlapping PDSCHs. If one first PDSCH whose sending is canceled is the last repetition in PDSCH repetitions of first data, and a terminal device receives another repetition in the PDSCH repetitions of the first data before the first PDSCH, the terminal device still sends feedback information for the first data to the network device in a feedback slot corresponding to the first PDSCH. In this way, a retransmission probability of the first data is reduced, and data transmission efficiency is improved.