EPDCCH Resource Mapping for Heterogeneous Network Capacity
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Solution Overview
Problem
Conventional wireless communication systems face challenges in supporting extended PDCCH capacity and interference coordination in heterogeneous networks, particularly with the use of Remote Radio Heads and pico-cells, where traditional PDCCH extensions are not feasible due to compatibility issues with conventional UEs.
Innovation Solution
The implementation of Enhanced PDCCH (EPDCCH) transmissions, which utilize PRB pairs within the PDSCH region, allowing for distributed ECCE structures across multiple PRB pairs to enhance capacity and interference randomization, while maintaining compatibility with conventional UEs through precise EREG and ECCE mapping and interleaving.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If PDCCH capacity is extended using traditional methods, then control channel capacity is improved, but compatibility with conventional UEs deteriorates
Solution Approach 1:
The control channel capacity is segmented into two parts: traditional PDCCH for conventional UEs and EPDCCH for advanced UEs. This segmentation allows each type of UE to access appropriate control channels without interfering with the other, resolving the contradiction between extending capacity and maintaining compatibility.
Solution Approach 2:
The patent introduces an intermediary mechanism where the network can dynamically indicate to UEs which control channel type (PDCCH or EPDCCH) to monitor. This intermediary signaling layer allows seamless coexistence of both UE types while enabling extended capacity through EPDCCH.
2Quantity of substance
If PDCCH resources are increased, then control channel capacity is improved, but interference coordination in heterogeneous networks deteriorates
Solution Approach 1:
The patent moves control channel transmissions from the traditional frequency dimension (PDCCH in control region) to the time-frequency resource block dimension (EPDCCH in PDSCH region). This dimensional shift allows better interference coordination in heterogeneous networks by enabling frequency-domain resource allocation and interference management.
Solution Approach 2:
The patent applies local quality by allowing different control channel structures (PDCCH and EPDCCH) in different network areas. Macro cells can use traditional PDCCH while pico cells or remote radio heads use EPDCCH, optimizing performance for each local network condition and reducing overall interference.
3Quantity of substance
If EPDCCH uses distributed ECCE structures across multiple PRB pairs, then capacity and interference randomization are improved, but system complexity increases
Solution Approach 1:
The patent changes key parameters of the control channel structure, including the number of resource blocks per ECCE, the aggregation levels, and the mapping patterns. By adjusting these parameters, the system can optimize capacity and interference randomization while managing complexity through standardized parameter sets.
Solution Approach 2:
The patent introduces dynamic aspects to ECCE mapping, where the network can flexibly configure the number of PRB pairs, the distribution pattern, and the aggregation level based on traffic conditions and interference scenarios. This dynamic configuration allows the system to adapt to changing conditions while maintaining manageable complexity through predefined mapping rules.
Data Source
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AI summary
Methods and apparatus are described for forming Control Channel Elements (CCEs) from Resource Element Groups (REGs) that are located in one or more Physical Resource Block (PRB) pairs from a set of PRB pairs, for determining a first symbol in a Transmission Time Interval (TTI) for a Physical Downlink Shared Channel (PDSCH), and for determining whether the PDSCH includes all PRB pairs indicated by a respective PDCCH scheduling the PDSCH.