ECCE-Based PDSCH Resource Allocation for LTE MTC
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current LTE systems face inefficiencies in scheduling Physical Downlink Shared Channel (PDSCH) resources, particularly for Machine-Type Communications (MTC) UEs with small bandwidth, where frequency diversity and reliable channel information feedback are limited, leading to suboptimal resource allocation and decoding challenges.
Innovation Solution
The implementation of Enhanced Control Channel Element (ECCE) based resource allocation for PDSCH, integrating with Enhanced Physical Downlink Control Channel (EPDCCH) and utilizing ECCE indexing for distributed EPDCCH, allowing PDSCH resource allocation to consist of resource elements from multiple PRB pairs, with a minimum unit size equivalent to a PRB pair, enabling frequency diversity and efficient decoding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional PDSCH resource allocation is used in LTE systems, then resource allocation can be performed, but resource allocation efficiency is suboptimal and decoding complexity increases for MTC UEs with small bandwidth
Solution Approach 1:
The patent changes the resource allocation parameters by introducing ECCE-based indexing instead of traditional RB-based allocation. The resource allocation is redefined using ECCE index ranges (startECCE, endECCE) and aggregation levels, which transforms the allocation granularity and reduces the search space for MTC UEs, thereby improving allocation efficiency while reducing decoding complexity.
Solution Approach 2:
The patent applies local quality optimization by tailoring the resource allocation scheme specifically for MTC UEs with small bandwidth. The ECCE-based allocation allows different aggregation levels (1, 2, 4, 8) to be configured based on channel conditions and UE capabilities, providing localized optimization for narrow bandwidth scenarios while maintaining compatibility with broader system requirements.
2Reliability
If frequency diversity is not utilized in PDSCH resource allocation, then resource allocation is simpler, but channel information feedback reliability deteriorates for MTC UEs
Solution Approach 1:
The patent segments the PDSCH resources into multiple ECCEs distributed across different PRB pairs. By allocating ECCEs with the same index across multiple PRB pairs, the system achieves frequency diversity through segmentation. This allows the same control information to be transmitted over multiple frequency resources, improving reliability without significantly increasing allocation complexity.
Solution Approach 2:
The patent implements a copying mechanism where ECCEs are replicated across multiple PRB pairs. The same ECCE index refers to corresponding control channel elements in different PRB pairs, creating redundant copies that provide frequency diversity. This copying approach enhances reliability by ensuring that if one copy is degraded, other copies can still be decoded successfully.
3Productivity
If PDSCH resource allocation is limited to single PRB pair, then allocation is simpler, but bandwidth utilization decreases for MTC UEs with small bandwidth
Solution Approach 1:
The patent introduces a new dimension to resource allocation by using ECCE indexing that spans multiple PRB pairs. Instead of allocating resources within a single PRB pair, the ECCE-based allocation extends across multiple PRB pairs in the frequency domain. This dimensional extension allows more efficient utilization of available bandwidth for MTC UEs while maintaining a relatively simple allocation mechanism through index-based referencing.
Data Source
AI summary
Aspects of the present disclosure provide techniques and apparatus for enhanced control channel element (ECCE) based physical downlink shared channel (PDSCH) resource allocation for long-term evolution (LTE). A method is provided for wireless communications by a user equipment (UE). The method generally includes determining resources assigned for a data channel, based on a resource granularity associated with a control channel and processing the data channel transmissions in a subframe based on the determination. The data channel may comprise a PDSCH. According to certain aspects, the UE may receive downlink control information (DCI) having a number of bits indicating VRBs assigned for PDSCH. Each VRB may include ECCEs from the same or different enhanced resource element group (EREG). ECCEs may span multiple PRB pairs or the same PRB pair. The UE may perform rate matching around enhanced physical downlink control channel (EPDCCH) overlapping assigned PDSCH resources.