ACK to NACK Error Detection via Packet Correlation
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Solution Overview
Problem
In wireless communication systems, especially those using multiple access techniques like TDMA, FDMA, CDMA, and OFDMA, it is inefficient to detect out-of-sequence transmissions caused by positive acknowledgments being mistaken as negative acknowledgments without explicit signaling, leading to packet sequencing errors and synchronization loss between transmitters and receivers.
Innovation Solution
The method involves correlating re-encoded data packets to determine if they are the same, with a high correlation indicating a correct acknowledgment and a low correlation indicating a new transmission, allowing the receiver to implicitly detect ACK-to-NACK errors without explicit sub-packet identification signaling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If explicit sub-packet identification signaling is used to detect ACK-to-NACK errors, then detection accuracy is improved, but bandwidth requirements and system complexity increase
Solution Approach 1:
The patent extracts the error detection function from explicit signaling and implements it through implicit correlation analysis of re-encoded packets. The correlator extracts correlation values between received packets and re-encoded versions, enabling ACK-to-NACK error detection without requiring additional explicit identification signals, thus reducing bandwidth requirements while maintaining detection accuracy
Solution Approach 2:
The patent introduces a correlator as an intermediary component that computes correlation values between received packets and re-encoded packets. This correlator serves as a mediator that enables implicit error detection by analyzing the relationship between packets without requiring explicit identification signaling, resolving the contradiction between detection accuracy and bandwidth efficiency
2Reliability
If explicit sub-packet identification signaling is used to detect out-of-sequence transmissions, then synchronization reliability is improved, but device complexity increases
Solution Approach 1:
The patent extracts the synchronization verification function from complex explicit signaling mechanisms and implements it through simple correlation analysis. The receiver uses the correlator to compute correlation values and compare them against thresholds, enabling synchronization reliability improvement without increasing device complexity through additional signaling infrastructure
Solution Approach 2:
The patent enables the system to self-verify synchronization status through autonomous correlation analysis. The receiver independently computes correlation values between received packets and re-encoded versions, and autonomously determines whether ACK-to-NACK errors occurred based on correlation thresholds, eliminating the need for complex external verification mechanisms
3Quantity of substance
If correlation analysis of re-encoded packets is used for error detection, then bandwidth efficiency is improved, but measurement precision may be reduced
Solution Approach 1:
The patent changes the parameter of error detection from explicit signal analysis to implicit correlation value analysis. By computing correlation values between received packets and re-encoded packets and comparing against predetermined thresholds, the system achieves accurate error detection through parameter transformation, maintaining precision while improving bandwidth efficiency
Solution Approach 2:
The patent applies local quality analysis by focusing correlation computation on specific packet regions and comparing correlation values at different positions. The receiver analyzes local correlation characteristics between received packets and re-encoded versions, enabling precise error detection in specific packet segments without requiring global explicit signaling
Data Source
AI summary
A method and apparatus to determine whether a transmission was successfully received in a multiple access communication system is claimed. First and second encoded data packets are received and decoded. The first and second data packets are then re-encoded, and correlated to determine whether the first and second re-encoded data packets are the same. If there is a high degree of correlation, an indicator of acknowledgement is transmitted to indicate that there is a high degree of correlation between the first and second re-encoded data packets. If there is a low degree of correlation, a determination is made that the previously transmitted indicator of acknowledgement was correctly received.