PUCCH Resource Compression for TDD EPDCCH
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Solution Overview
Problem
The current LTE specifications face challenges in efficiently allocating uplink resources for PUCCH in TDD EPDCCH, leading to increased signaling overhead and resource wastage due to reserved PUCCH resources not being utilized effectively across subframes in a bundling window.
Innovation Solution
The proposed solution involves dynamically allocating PUCCH resources by using a two-bit ARO field and an additional parameter N_PUCCH,q_el to adjust and separate PUCCH resource indices, allowing for flexible allocation and minimizing reserved resources by employing large negative ARO values to shift the PUCCH resource index range, thereby optimizing resource usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If PUCCH resources are reserved for all subframes in a bundling window, then reliability of ACK/NACK transmission is improved, but signaling overhead increases and resource allocation efficiency deteriorates
Solution Approach 1:
The patent extracts only the necessary PUCCH resources by dynamically allocating them based on actual EPDCCH transmission locations rather than reserving resources for all possible subframes. This removes unnecessary reserved resources while maintaining reliability for actual transmissions.
Solution Approach 2:
The patent implements dynamic PUCCH resource allocation where the resource index is adjusted based on the actual EPDCCH subframe location using the formula n_PUCCH = n_PUCCH,0 + ΔARO + N_PUCCH,q_el. This dynamic adjustment allows resources to adapt to actual transmission needs rather than being statically reserved.
2Reliability
If PUCCH resources are reserved for all subframes in a bundling window, then reliability of ACK/NACK transmission is improved, but resource allocation efficiency worsens
Solution Approach 1:
The patent extracts and eliminates redundant reserved PUCCH resources by allocating resources dynamically based on actual EPDCCH transmission locations. This removes wasted resources while preserving reliability for actual transmissions.
Solution Approach 2:
The patent changes the PUCCH resource index parameter dynamically using the formula n_PUCCH = n_PUCCH,0 + ΔARO + N_PUCCH,q_el, where ΔARO and N_PUCCH,q_el adjust the resource allocation based on actual transmission conditions, improving resource utilization efficiency.
3Productivity
If implicit signaling based on EPDCCH structure is used, then resource allocation efficiency is improved, but complexity of resource index management increases
Solution Approach 1:
The patent introduces ΔARO and N_PUCCH,q_el as intermediary parameters that mediate between the base resource index n_PUCCH,0 and the final allocated resource n_PUCCH. These intermediaries simplify the mapping process by providing structured adjustment mechanisms.
Solution Approach 2:
The patent uses parameter changes (ΔARO and N_PUCCH,q_el) to adjust the PUCCH resource index based on EPDCCH structure, enabling efficient implicit signaling while maintaining manageable complexity through systematic parameter adjustment rules.
Data Source
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AI summary
Techniques are described for compressing the PUCCH resources reserved for acknowledging downlink data transmissions when those resources are implicitly signaled by EPDCCHs that schedule the downlink transmissions in TDD mode. An acknowledgement resource offset field transmitted in the EPDCCH is configured to correspond to one or more values that compress the region in PUCCH resource index space that would otherwise be reserved for the subframes of a bundling window.