Logical to Physical PUCCH Resource Block Mapping in LTE Uplink
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Solution Overview
Problem
In wireless cellular communication networks, particularly in 3GPP LTE systems, there is a challenge in efficiently mapping logical uplink control resource blocks to physical resource blocks for the physical uplink control channel (PUCCH), which affects the reliability and multiplexing capacity of ACK/NAK transmissions, especially in larger system bandwidths where multiple resource blocks are assigned for PUCCH.
Innovation Solution
The proposed solution involves specific mapping schemes between logical PUCCH resource blocks and physical resource blocks, including equations that map logical PUCCH RB indices to physical RBs, allowing for efficient allocation and utilization of resources, such as equations (1) to (8), which describe different mapping strategies to optimize resource usage and support higher multiplexing capacities for ACK/NAK channels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If multiple resource blocks are assigned for PUCCH in larger system bandwidths, then the multiplexing capacity for ACK/NAK channels is improved, but the mapping complexity between logical and physical resource blocks increases
Solution Approach 1:
The patent segments the mapping process into distinct cases based on the number of PUCCH resource blocks (one RB vs. multiple RBs). For single RB, a direct mapping is used, while for multiple RBs, a segmented mapping approach divides the logical RB space into segments that map to different physical RBs, reducing overall mapping complexity while maintaining high multiplexing capacity.
Solution Approach 2:
The patent changes the mapping parameter nPUCCH,LRB (logical RB index) to different physical RB indices based on the system configuration. By dynamically adjusting the mapping parameters according to the number of PUCCH RBs and the specific ACK/NAK channel index, the system achieves flexible multiplexing capacity adaptation without requiring complex fixed mapping structures.
2Reliability
If resource blocks are allocated at extreme edges of uplink frequency spectrum for PUCCH, then transmission reliability is improved, but resource utilization efficiency deteriorates
Solution Approach 1:
The patent applies local quality by allocating PUCCH resources specifically at the extreme edges of the uplink frequency spectrum, where interference conditions are locally optimized for control channel reliability. This localized resource allocation strategy ensures high transmission reliability for ACK/NAK channels while allowing central frequency resources to be fully utilized for data transmission, thus maintaining overall resource utilization efficiency.
3Reliability
If frequency resources are allocated separately for PUCCH and PUSCH, then control information transmission reliability is improved, but system flexibility deteriorates
Solution Approach 1:
The patent introduces dynamic mapping between logical and physical resource blocks that can adapt to different system configurations. The mapping relationship is not fixed but can be dynamically adjusted based on the number of PUCCH RBs, the index of the logical RB, and the specific ACK/NAK channel being transmitted. This dynamic approach maintains separate frequency resource allocation for reliability while providing system flexibility through configurable mapping parameters.
Data Source
AI summary
A transmission of information from a secondary to a primary node occurs in a plurality of N logical time durations on an uplink channel in a wireless network. A scheme for mapping between logical uplink control channel (PUCCH) resource blocks (RBs) and physical RBs (PRBs) used by PUCCH is described. A logical uplink control resource block index nLRB is derived by the secondary node in response to information from the primary node. The secondary node then maps the logical uplink control resource block index nLRB to a first uplink physical resource block index nPRB,1 of a plurality of uplink physical resource blocks, wherein nPRB,1=nLRB/2 if nLRB is even and nPRB,1=NPRB−ceil(nLRB/2) if nLRB is odd; wherein NPRB is the total number of the plurality of uplink physical resource blocks; and wherein ceil denotes the ceiling operation. The secondary node then transmits an uplink control information in a subframe using one of the plurality of uplink physical resource blocks indexed by nPRB,1.