PUCCH Cell Selection via Bitmap Mapping
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Solution Overview
Problem
Current 5G wireless communication systems face challenges in efficiently managing uplink transmission across multiple cells, particularly in determining the optimal cell for transmitting physical uplink control channels (PUCCH) due to overlapping transmissions and varying configurations, which can lead to increased latency and reduced coverage.
Innovation Solution
A method is introduced where user equipment (UE) and base stations (BS) receive bitmap mappings to identify primary and secondary cells, allowing them to determine the appropriate cell for PUCCH transmission based on periodic slot mappings and specific parameters for PUCCH transmission on each cell, enabling flexible cell selection and resource allocation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If PUCCH transmission is restricted to a single primary cell, then device complexity is reduced, but productivity decreases due to limited transmission opportunities and increased latency
Solution Approach 1:
The patent implements dynamic cell selection for PUCCH transmission by introducing a bitmap configuration that varies across slots. The UE determines the transmitting cell based on the bitmap value in each slot, allowing the system to dynamically switch between primary and secondary cells for PUCCH transmission. This dynamic approach increases transmission opportunities and reduces latency while maintaining manageable device complexity through standardized procedures.
Solution Approach 2:
The patent segments the PUCCH transmission function across multiple cells by configuring separate PUCCH resources on both primary and secondary cells. The bitmap divides slot resources between these cells, enabling the system to utilize multiple segmented transmission paths simultaneously, thereby improving overall transmission efficiency without requiring the UE to manage all transmissions on a single cell.
2Productivity
If PUCCH transmission is allowed on multiple cells, then productivity improves through increased transmission opportunities, but device complexity increases due to multiple parameter configurations
Solution Approach 1:
The patent applies universality by configuring PUCCH resources on both primary and secondary cells with similar parameter structures. The same types of parameters (time offset, frequency offset, resource allocation) are used across both cells, allowing the UE to handle multiple cell configurations using a unified processing framework. This reduces the effective complexity despite supporting multiple transmission cells.
Solution Approach 2:
The bitmap configuration acts as an intermediary that simplifies the interaction between multiple PUCCH resources. Instead of requiring the UE to continuously evaluate which cell to use based on complex conditions, the bitmap provides a straightforward mapping from slot index to transmitting cell, mediating the complexity of multi-cell coordination through a simple periodic pattern.
3Adaptability or versatility
If bitmap-based cell selection is implemented, then adaptability improves for flexible resource allocation, but difficulty of detecting and measuring increases due to periodic mapping interpretation
Solution Approach 1:
The patent employs periodic bitmap patterns for cell selection, where the bitmap repeats across slots with a defined period. This periodic structure makes the mapping interpretation straightforward - the UE only needs to determine the bitmap period and offset once, then automatically derives the transmitting cell for any given slot using the repeating pattern. This reduces the ongoing complexity of detecting and measuring which cell to use.
Solution Approach 2:
The system performs preliminary configuration of the bitmap parameters (period, offset, pattern) through higher-layer signaling before actual PUCCH transmission begins. This preliminary action establishes the cell selection rules in advance, so the UE does not need to perform complex real-time analysis during transmission. The difficult interpretation work is done beforehand, allowing simple runtime decision-making.
Data Source
AI summary
Methods and apparatuses for cell selection for uplink transmission. A method for operating a user equipment includes receiving: a bitmap mapping to a number of slots on a primary cell. The mapping repeats periodically over the number of slots. The bitmap indicates the primary cell or a secondary cell. The method further includes receiving information for first parameters associated with transmission of a physical uplink control channel (PUCCH) on the primary cell and information for second parameters associated with transmission of a PUCCH on the secondary cell. The method further includes determining, based on the bitmap, a first cell to transmit a first PUCCH in a slot of the first cell and transmitting the first PUCCH in the slot on the first cell.