Negative Acknowledgment Mechanisms for Wireless PPDU Feedback
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Solution Overview
Problem
Current wireless communication systems lack a signaling mechanism to provide negative acknowledgment (NACK) of physical layer protocol data units (PPDUs), which hinders feedback on channel conditions and interferes with efficient transmission adjustments.
Innovation Solution
Implementing a signaling mechanism that allows receivers to generate and output frames indicating negative acknowledgment of at least a portion of a PPDU, based on specific conditions such as decoding failures or channel conditions, to facilitate adjustments in transmit parameters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional positive acknowledgment mechanisms are used, then transmission reliability can be maintained for successful packets, but the system lacks the capability to provide feedback on failed transmissions and channel conditions
Solution Approach 1:
The patent inverts the traditional acknowledgment approach by introducing negative acknowledgment (NACK) frames that explicitly signal transmission failures. Instead of only confirming successful receptions, the system now actively communicates decoding failures and channel conditions through NACK frames, enabling the transmitter to adapt its strategy based on negative feedback about channel quality.
Solution Approach 2:
The patent implements a feedback mechanism where receivers send NACK frames containing decoding failure information and channel condition data back to transmitters. This feedback loop enables continuous adaptation of transmission parameters based on actual channel performance, improving reliability by allowing dynamic adjustments to coding schemes, modulation, and power based on real-time channel assessments.
2Device complexity
If no negative acknowledgment mechanism is implemented, then the signaling protocol remains simple, but the system cannot efficiently adjust transmission parameters based on channel conditions
Solution Approach 1:
The patent introduces dynamic adaptability to the transmission system by enabling real-time adjustment of transmission parameters based on channel conditions communicated through NACK frames. The system transitions from static transmission parameters to dynamic parameter selection, where coding rate, modulation scheme, and power levels are continuously adapted based on feedback about channel quality and decoding success.
3Productivity
If immediate feedback on transmission failures is provided through NACK frames, then retransmission efficiency improves, but the communication protocol becomes more complex
Solution Approach 1:
The patent enables preliminary actions by providing immediate NACK feedback that allows the transmitter to proactively adjust transmission parameters before attempting retransmission. Rather than using default retransmission parameters, the system can pre-adapt coding schemes, modulation, and power levels based on the channel condition information contained in the NACK frame, making retransmissions more likely to succeed on the first attempt.
Data Source
AI summary
This disclosure provides methods, components, devices and systems that may help various wireless devices negatively acknowledge certain wireless transmissions. An example method, performed at a first wireless node, generally includes obtaining information indicating transmission, from a second wireless node, of a physical layer (PHY) protocol data unit (PPDU) intended for the first wireless node, generating a frame indicating negative acknowledgment of at least a portion of the PPDU if one or more conditions are met, and outputting the frame to the second wireless node.