ACK/NACK Channel Allocation for Reliable FDMA Retransmission
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Solution Overview
Problem
In FDMA wireless communication systems, the dedicated allocation of resources for ACK/NACK signals is inefficient, leading to resource wastage and unreliable ACK/NACK transmission, especially for UEs at the cell boundary, due to collisions and insufficient allocation of ACKCHs for repeated transmissions.
Innovation Solution
Allocating more ACKCHs than DCHs or SCCHs and selecting supplementary ACKCHs for ACK/NACK repetition, allowing UEs to transmit ACK/NACK signals on dedicated channels, thereby avoiding collisions and ensuring reliable transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If dedicated ACKCH resources are allocated for each UE, then ACK/NACK transmission reliability is improved, but resource utilization efficiency deteriorates
Solution Approach 1:
The patent segments the ACKCH resources by creating two distinct types: basic ACKCH resources for normal ACK/NACK transmission, and supplementary ACKCH resources specifically for ACK/NACK repetition transmissions. This segmentation allows the system to dedicate resources only where needed (for UEs requiring repetition) while sharing resources for normal operations, thus resolving the contradiction between reliability and resource efficiency.
Solution Approach 2:
The patent introduces a new dimension to resource allocation by adding supplementary ACKCH resources that operate in parallel with basic ACKCH resources. This dimensional expansion allows the system to handle both normal and repeated ACK/NACK transmissions simultaneously without interfering with each other, improving reliability for edge UEs while maintaining overall resource efficiency.
2Reliability
If ACK/NACK repetition is implemented for cell boundary UEs, then transmission reliability is improved, but resource overhead increases
Solution Approach 1:
The patent applies local quality by providing supplementary ACKCH resources specifically to UEs at the cell boundary that require ACK/NACK repetition, while UEs with good signal conditions use only the basic ACKCH resources. This localized approach ensures that resource overhead is incurred only where necessary, rather than universally for all UEs, thus improving reliability for vulnerable UEs without excessive resource consumption.
3Reliability
If supplementary ACKCH resources are allocated for ACK/NACK repetition, then signal collisions are prevented, but system complexity increases
Solution Approach 1:
The patent implements preliminary action by pre-configuring supplementary ACKCH resources and establishing the mapping relationships between basic and supplementary ACKCH before actual ACK/NACK transmission occurs. This advance preparation allows the system to handle ACK/NACK repetition without real-time complexity, as the resource allocation decisions are predetermined based on UE location and channel conditions.
Data Source
AI summary
A method and apparatus for transmitting/receiving an ACKnowledgement/Negative ACKnowledgement (ACK/NACK) signal to support packet data retransmission in an Frequency Division Multiple Access (FDMA) wireless communication system are provided, in which a User Element (UE) generates an ACK/NACK signal for received packet data, determines whether the UE is set to support ACK/NACK repetition, transmits the ACK/NACK signal on a basic response channel mapped to one of a DCH on which the packet data was received and a Shared Control Channel (SCCH) carrying scheduling information about the packet data, if the UE is not set to support ACK/NACK repetition, and selects one of supplementary response channels for each ACK/NACK repetition, the supplementary response channels being allocated for ACK/NACK repetition and repeatedly transmits the ACK/NACK signal on the selected supplementary response channel according to a predetermined repetition factor, if the UE is set to support ACK/NACK repetition.