EPDCCH Candidate Segmentation for Terminal Monitoring Complexity
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Solution Overview
Problem
Current LTE communication systems face inefficiencies in terminal device communication with base stations due to suboptimal monitoring of User Equipment-specific Search Spaces (USS) and transmission methods over the downlink channel, particularly in managing Enhanced Physical Downlink Control Channel (EPDCCH) candidates.
Innovation Solution
The solution involves determining specific sets of EPDCCH candidates based on Carrier Indicator Field (CIF) values and aggregation levels, using expressions to calculate the number of candidates and corresponding Enhanced Control Channel Elements (ECCEs) for efficient monitoring and transmission, enhancing communication efficiency between terminal devices and base stations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the terminal device monitors all EPDCCH candidates in the USS without differentiation, then the coverage is complete, but the processing load and complexity increase
Solution Approach 1:
The patent segments the EPDCCH candidates into two distinct sets: a first set for DCI format 0/1A and a second set for other DCI formats. This segmentation is achieved through different starting positions (Eq. 1 vs Eq. 2) and different numbers of candidates (N¹ vs N²), allowing the terminal to efficiently search through candidates without processing redundancy, thus reducing monitoring complexity while maintaining complete coverage.
Solution Approach 2:
The patent applies local quality by assigning different properties to different sets of EPDCCH candidates. The first set uses a specific starting position and candidate count optimized for DCI format 0/1A, while the second set uses different parameters optimized for other DCI formats. This localized optimization reduces the overall monitoring load while ensuring each format is efficiently detected.
2Reliability
If the number of EPDCCH candidates is increased to improve detection reliability, then the reliability improves, but the processing time and energy consumption increase
Solution Approach 1:
By dividing EPDCCH candidates into two sets with different starting positions and candidate counts, the patent enables parallel processing of different DCI formats. The terminal can simultaneously search the first set for format 0/1A and the second set for other formats, reducing total processing time while maintaining detection reliability through adequate candidate numbers in each set.
3Productivity
If the EPDCCH monitoring is optimized for specific DCI formats, then the processing efficiency improves, but the adaptability to different DCI formats decreases
Solution Approach 1:
The patent achieves local quality optimization by creating specialized search spaces for different DCI formats. The first set is optimized for format 0/1A with specific starting position and candidate count, while the second set is optimized for other formats. This allows efficient processing for each format type while maintaining overall adaptability through the dual-set structure that covers all DCI formats.
Data Source
AI summary
A terminal device and a base station device can efficiently communicate with each other by using a downlink channel. The terminal device monitors, in an EPDCCH-PRB-set p in a subframe k, a first set ESk(L) of first EPDCCH candidates and a second set ESk(L) of second EPDCCH candidates. A first number Mp,c(L) of the first EPDCCH candidates is determined according to a first αp,c and Mp(L), and a second number Mp,c(L) of the second EPDCCH candidates is determined according to a second αp,c and Mp(L). First ECCE(s) corresponding to an mth first EPDCCH candidate included in the first set ESk(L) and second ECCE(s) corresponding to an mth second EPDCCH candidate included in the second set are determined according to a first value. The first value is given by a following expression, where NECCE,p,k is a total number of ECCEs included in the EPDCCH-PRB-set p in the subframe k.