Wireless Communication Node HARQ-ACK Scrambling with RNTIs
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Solution Overview
Problem
The NR system needs to support simultaneous reception of unicast and multicast/groupcast services in one timeslot, requiring a redesign of uplink feedback mechanisms, particularly for multiplexing HARQ-ACKs, which is not adequately addressed in existing standards.
Innovation Solution
A method and device that scramble HARQ-ACKs for unicast and multicast/groupcast services using different RNTIs, allowing them to be multiplexed in a single physical channel with minimal standard changes, enhancing reception performance by enabling multiple base stations to receive multicast/groupcast HARQ-ACKs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If HARQ-ACK for unicast and multicast/groupcast are multiplexed in one physical channel, then feedback flexibility is improved, but feedback reliability deteriorates due to potential loss of multicast feedback when unicast feedback is present
Solution Approach 1:
The feedback bit block is segmented into multiple parts, where each part corresponds to different service types (unicast, multicast/groupcast). Different RNTIs are used to scramble different segments, allowing base stations to selectively receive and decode relevant feedback information while maintaining overall feedback flexibility through unified multiplexing.
2Reliability
If different RNTIs are used to scramble HARQ-ACK for different services, then feedback reliability is improved through selective reception, but device complexity increases due to multiple scrambling operations
Solution Approach 1:
The same feedback bit block structure and multiplexing mechanism serve multiple functions: it simultaneously carries HARQ-ACK for both unicast and multicast/groupcast services. The system uses a unified feedback channel design that can adaptively support different service types through RNTI-based scrambling, reducing the need for separate feedback mechanisms and thereby lowering overall device complexity.
3Device complexity
If unified feedback mechanism is adopted for unicast and multicast/groupcast, then device complexity is reduced, but reception performance deteriorates as multiple base stations cannot reliably receive multicast feedback
Solution Approach 1:
Different quality measures are applied to different parts of the feedback based on service type. Multicast feedback bits are scrambled with G-RNTI for reliable reception by multiple base stations, while unicast feedback bits use C-RNTI for dedicated reception. This localized differentiation within the unified feedback structure ensures that each service type receives the appropriate level of reception reliability while maintaining overall system simplicity.
Data Source
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AI summary
The disclosure provides a method and a device in a node for wireless communication. A node first receives K1 first-type signals, and then transmits a target signal, the target signal carrying a first bit block, wherein the first bit block includes K1 first-type information blocks, the K1 first-type information blocks are used for indicating whether the K1 first-type signals are correctly received respectively; a target identifier is used for generating a scrambling code of the target signal; one of the K1 first-type signals carries a first identifier, a second identifier is one identifier not equal to the first identifier, the target identifier is equal to one of the first identifier or the second identifier; whether one of the K1 first-type signals carries the second identifier is used for determining the target identifier. The disclosure provides a method and device for optimizing a scrambling mode of feedback information under multicast and groupcast, thereby optimizing system performances.