Uplink Control Piggybacking Feedback Bit Reservation
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Solution Overview
Problem
Current wireless communication systems face inefficiencies in utilizing resources for uplink control information (UCI) piggybacking on the physical uplink shared channel (PUSCH), particularly in managing reserved resources for hybrid automatic repeat request (HARQ) feedback, leading to undesirable power spectral density (PSD) differences across symbol durations.
Innovation Solution
The method involves reserving specific resource elements (REs) for HARQ feedback within a transmission time interval (TTI) and mapping a predetermined pattern of bits to unused reserved REs, ensuring efficient utilization of PUSCH resources by prioritizing channel state information (CSI) mapping and handling varying feedback bit sizes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If resources are reserved for HARQ feedback in PUSCH, then feedback transmission reliability is improved, but resource utilization efficiency deteriorates due to unused reserved REs
Solution Approach 1:
The patent recovers unused reserved resource elements by repurposing them for CSI transmission. When HARQ feedback requires fewer REs than reserved, the remaining reserved REs are discarded from their original purpose and recovered for alternative use in carrying CSI, thereby eliminating resource waste while maintaining HARQ feedback reliability.
Solution Approach 2:
The patent makes reserved REs multi-functional by enabling them to serve dual purposes: primarily for HARQ feedback transmission, and secondarily for CSI transmission when HARQ feedback requires fewer resources. This universality allows the same reserved resources to adaptively serve different functions based on actual needs, improving overall resource utilization.
2Measurement precision
If reserved REs are left unused when feedback bits are few, then feedback accuracy is maintained, but PSD variations increase causing communication inefficiency
Solution Approach 1:
The patent achieves homogeneity in PSD distribution by fully utilizing all reserved REs for either HARQ feedback or CSI transmission, eliminating the heterogeneous state where some REs are used and others remain unused. This uniform resource utilization ensures consistent PSD across all reserved resources, improving communication efficiency while preserving feedback accuracy through proper resource allocation.
3Reliability
If more resources are allocated for HARQ feedback, then feedback reliability is improved, but available resources for data transmission are reduced
Solution Approach 1:
The patent implements dynamic resource allocation where the amount of resources dedicated to HARQ feedback adapts based on actual feedback requirements. When fewer feedback bits need transmission, previously reserved resources are dynamically reallocated to CSI transmission, ensuring that HARQ feedback receives adequate resources for reliability while maximizing overall resource utilization for both control information types.
Data Source
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AI summary
A wireless device may identify a set of resources reserved for feedback information (e.g., resource elements (REs) reserved for feedback such as acknowledgement (ACK) or negative ACK (NACK) information) within a transmission time interval (TTI). Feedback information may be mapped to the reserved set of resources (e.g., reserved REs). The wireless device may determine a set of unused reserved resources (e.g., a set of unused reserved REs) based on the number of feedback bits. The wireless device may then map other bits (e.g., zeros, known bits, pattern or sequence of bits, random bits, etc.) to the set of unused reserved REs, or boost transmission power of bits mapped around the unused reserved REs. In some cases, the number of reserved REs may be determined based on the number of feedback bits (e.g., the size of the ACK/NACK payload). The wireless device may then transmit the information to a base station.