PUCCH Resource Allocation for TDD EPDCCH Collision Avoidance

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Solution Overview

Problem

In wireless communications networks, particularly for TDD operations, PUCCH format 1a/1b resource allocation faces challenges with resource collisions between multiple DL subframes mapping to a single UL subframe, leading to inefficient resource utilization and increased overhead, as existing solutions fail to guarantee collision-free operations without excessive resource fragmentation.

Innovation Solution

The solution involves extending the definition of semi-static resource starting offsets for each EPDCCH set and enhancing the dynamic offset mechanism to adapt to the number of DL subframes mapping to a single UL subframe, allowing for fully orthogonal PUCCH resources and minimizing scheduling restrictions, by introducing a TDD-specific parameter and dynamic offset modifiers derived from downlink control information.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If existing PUCCH resource allocation methods are used for TDD operations, then resource allocation is simple, but resource collisions occur between multiple DL subframes mapping to a single UL subframe

Engineering Contradiction:
Improvecollision-free operationVSAvoidresource allocation mechanism
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces TDD-specific parameters (n_offset and M) to modify the resource allocation formula. The parameter n_offset represents the starting offset for PUCCH resources, and M represents the number of DL subframes mapping to a single UL subframe. By changing these parameters dynamically based on TDD configuration, the system achieves collision-free resource allocation while adapting to different TDD modes without excessive complexity

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The resource allocation mechanism is made dynamic by introducing configurable offsets that can be adjusted based on the number of DL subframes (M) mapping to a single UL subframe. The formula n_PUCCH = n_eCCE + n_offset allows the network to dynamically allocate orthogonal PUCCH resources by adjusting n_offset according to the specific TDD configuration and the value of M, thereby avoiding resource collisions in a flexible manner

Inventive Principle:
Principle #15Dynamics

2Reliability

If resource allocation is extended to handle multiple DL subframes, then collision-free operation is achieved, but resource fragmentation and overhead increase

Engineering Contradiction:
Improvecollision-free operationVSAvoidresource overhead
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent segments the PUCCH resource space by introducing a starting offset n_offset that divides the resource allocation into distinct segments. Each segment corresponds to a specific range of DL subframes (M), allowing orthogonal resource allocation without requiring the entire PUCCH resource pool to be reserved. This segmentation approach reduces resource overhead by allocating only the necessary portion of resources for each TDD configuration

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies partial action by allocating PUCCH resources only for the specific number of DL subframes (M) that actually map to a single UL subframe in each TDD configuration, rather than reserving resources for all possible subframes. This partial allocation approach minimizes resource overhead while ensuring collision-free operation for the actual traffic patterns

Inventive Principle:
Principle #16Partial or excessive action

3Productivity

If orthogonal PUCCH resources are allocated for multiple DL subframes, then resource utilization efficiency improves, but scheduling restrictions increase

Engineering Contradiction:
Improveresource utilization efficiencyVSAvoidscheduling flexibility
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent creates a universal resource allocation formula (n_PUCCH = n_eCCE + n_offset) that works across multiple TDD configurations and scenarios. The formula can handle different values of M (number of DL subframes) and different TDD UL-DL configurations through a single unified mechanism, maintaining scheduling flexibility while achieving orthogonal resource allocation. This multi-functional approach eliminates the need for separate allocation mechanisms for different scenarios

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP2713543B1Pucch resource allocation for e-pdcch in communications system
Publication Date: 2015.11.18 NOKIA SOLUTIONS & NETWORKS OY
  • EP2713543B1 patent drawingFigure 1~2
  • EP2713543B1 patent drawingFigure 3~4
  • EP2713543B1 patent drawingFigure 5

AI summary

An exemplary embodiment discloses a multi-subframe physical uplink control channel PUCCH resource arrangement for PUCCH format 1a/1b resource allocation for enhanced physical downlink control channel EPDCCH in time division duplex TDD transmission. A definition of a semi-static offset for each EPDCCH set is extended by considering multiple downlink subframes, and a dynamic offset mechanism is enhanced to avoid resource collision between multiple DL subframes.