eMTC MPDCCH Monitoring Across NTN RTD and HARQ Windows
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Solution Overview
Problem
The timing offset introduced in eMTC for non-terrestrial networks (NTN) due to long receiver and transmitter distances affects the MPDCCH search space period and HARQ process, leading to inefficiencies in uplink transmission scheduling.
Innovation Solution
The MPDCCH search space period is redesigned by adjusting the scaling factor G to G0 and introducing a new period T0, along with specific offsets and monitoring windows, to align with the RTD duration and HARQ process limitations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the MPDCCH search space period is extended to accommodate the RTD duration in NTN, then the timing alignment with satellite communication is improved, but the HARQ process complexity increases due to the need to manage multiple HARQ processes within the extended period
Solution Approach 1:
The extended MPDCCH search space period T0 is segmented into multiple regular search space periods T, where T = G × Rmax. Each segment corresponds to a specific HARQ process window, allowing the system to manage the extended period through structured divisions rather than treating it as a single complex period. This segmentation enables systematic handling of multiple HARQ processes while maintaining timing alignment with NTN requirements.
Solution Approach 2:
The patent introduces dynamic parameters including the number of search space periods N within T0, the scaling factor G, and the maximum repetitions Rmax. These parameters can be adjusted based on the specific RTD duration and HARQ process requirements, allowing the system to adaptively optimize the balance between timing alignment and complexity management for different NTN scenarios.
2Reliability
If the number of MPDCCH repetitions Rmax is increased to improve coverage in NTN, then the monitoring duration is extended, but the search space period T becomes excessively long, reducing scheduling flexibility
Solution Approach 1:
Instead of extending coverage solely by increasing Rmax in a single dimension, the patent introduces a new dimensional parameter N (number of search space periods) and the extended period T0. This allows coverage to be achieved through multiple smaller periods T rather than one excessively long period, maintaining scheduling flexibility while ensuring adequate monitoring duration for NTN coverage requirements.
3Productivity
If the search space period T is shortened to improve scheduling flexibility, then the response time is reduced, but the monitoring duration becomes insufficient for the RTD duration in NTN
Solution Approach 1:
The patent merges multiple regular search space periods T into an extended search space period T0 that spans the RTD duration. By combining N periods (T0 = N × T), the system achieves sufficient total monitoring duration for NTN while each individual period T remains short enough to maintain scheduling flexibility. This merging approach allows the system to benefit from both short-period agility and long-period coverage.
Data Source
AI summary
Methods and apparatuses for eMTC scheduling are disclosed. A method comprises receiving a control signal in a search space; and transmitting an uplink data after a first time duration of receiving the control signal or of receiving a downlink signal scheduled by the control signal, wherein the first time duration is comprised of at least one of a second time duration and a time duration offset (Koffset).