HARQ Process Configuration for MTC Wireless Systems
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Solution Overview
Problem
Wireless access systems face challenges in supporting Hybrid Automatic Retransmission Request (HARQ) operations for Machine Type Communication (MTC), particularly in setting the number of HARQ processes for MTC user equipment (UE) to efficiently manage downlink and uplink communications.
Innovation Solution
The method involves establishing a hybrid automatic retransmission request process in a wireless access system supporting MTC, allowing for the accurate setting of HARQ processes to optimize HARQ operations for MTC UE, thereby efficiently utilizing radio resources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the number of HARQ processes is increased to support MTC UE, then communication reliability is improved, but system complexity increases
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the number of HARQ processes based on MTC UE requirements. The base station configures a specific number of HARQ processes (e.g., 2 processes for uplink, 4 processes for downlink) through RRC signaling, changing the operational parameters to match MTC communication patterns while managing system complexity through controlled configuration rather than unlimited expansion
Solution Approach 2:
The patent segments HARQ operations into separate uplink and downlink process groups, with distinct process numbers allocated for each direction. Uplink HARQ processes are managed independently from downlink HARQ processes, allowing targeted optimization and simplifying the management complexity by dividing the overall HARQ system into manageable segments
2Stability of the object's composition
If HARQ processes are configured for MTC UE with repeated transmissions, then communication stability is improved, but radio resource utilization efficiency deteriorates
Solution Approach 1:
The patent implements periodic action through repeated transmissions of control information and user data for MTC UE. The same transport blocks are transmitted multiple times across different subframes with the same HARQ process ID, creating a periodic transmission pattern that enhances stability through redundancy while allowing the system to recover from poor channel conditions
Solution Approach 2:
The patent applies dynamics by making the HARQ process configuration adaptive to MTC UE conditions. The base station dynamically determines the number of HARQ processes and their allocation based on traffic patterns, channel conditions, and UE capabilities, allowing the system to optimize between stability and resource efficiency rather than using fixed configurations
3Ease of operation
If existing HARQ determination methods are used for general cellular UE, then operation simplicity is maintained, but applicability to MTC environment deteriorates
Solution Approach 1:
The patent achieves universality by creating a HARQ determination method that works for both general cellular UEs and MTC UEs. The same fundamental HARQ process determination formula is used, but with adjustable parameters (number of processes, process IDs) that can be configured differently for MTC UEs through RRC signaling, allowing one method to serve multiple purposes
Data Source
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AI summary
The present invention relates to a wireless access system which supports machine-type communication (MTC), and more specifically, to various methods for establishing the number of hybrid automatic retransmission request (HARQ) processes to support HARQ, and to apparatuses supporting same. A method for establishing the number of HARQ processes in a wireless access system which supports machine-type communication (MTC), according to one embodiment of the present invention, may comprise the steps of: determining, by a base station, the number of HARQ processes to be applied to an MTC terminal; and transmitting, by the base station, downlink control information including a HARQ process value allocated to the MTC terminal from among the determined number of HARQ processes. The number of HARQ processes can be determined on the basis of at least one of the number (N1) of repeated transmissions of a physical downlink control channel (PDCCH) to the MTC terminal, time (F) required for the MTC terminal to receive and process the repeatedly transmitted PDCCH, the number (N2) of repeated transmissions of a physical downlink shared channel (PDSCH), time (p1) required for the MTC terminal to receive and process the repeatedly transmitted PDSCH, the number (N3) of repeated transmissions of a physical uplink control channel (PUCCH), and time (p0) required for the base station to receive and process the repeatedly transmitted PUCCH.