MTC-EPDCCH Subband Control Channel Reception for MTC Devices
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Solution Overview
Problem
Machine-type communication (MTC) devices face difficulties in receiving the existing Physical Downlink Control Channel (PDCCH) transmitted over the entire system band, particularly when operating on a subband of about 1.4 MHz, leading to challenges in proper channel reception and coverage extension.
Innovation Solution
A modified control channel, referred to as MTC-EPDCCH or M-PDCCH, is introduced, which is a form of the existing Enhanced Physical Downlink Control Channel (EPDCCH), optimized for operation within a subband, with specific RE mapping and ECCE index configurations adapted for both normal and special subframes to ensure effective transmission and reception.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If MTC devices operate on a subband of about 1.4 MHz to reduce cost and complexity, then device cost and complexity are reduced, but the ability to properly receive the existing PDCCH transmitted over the entire system band deteriorates
Solution Approach 1:
The control channel reception is segmented into two parts: the existing PDCCH for general control information and a newly introduced control channel specifically for MTC devices operating in subbands. This segmentation allows MTC devices to receive appropriate control information without requiring full system band operation, thereby reducing device complexity while maintaining reliable control channel reception through the dedicated subband control channel
Solution Approach 2:
A new control channel is introduced as an intermediary between the base station and MTC devices operating in subbands. This intermediary control channel enables MTC devices to receive control information within their limited subband operation, resolving the contradiction between reduced device complexity and maintained reception reliability
2Area of stationary object
If the existing PDCCH is transmitted over the entire system band, then control coverage is maximized, but MTC devices operating on a subband cannot properly receive it
Solution Approach 1:
The control channel transmission is differentiated by location: the existing PDCCH serves the entire system band while a new control channel is specifically designed for MTC devices in subbands. This local quality approach ensures that each region receives appropriate control information, maintaining overall coverage while enabling reliable reception for subband-operating MTC devices
Solution Approach 2:
The control channel functionality is segmented into general-purpose PDCCH for wide coverage and a dedicated control channel for subband MTC devices. This segmentation allows the system to maintain maximum coverage through PDCCH while providing reliable reception for subband devices through the dedicated channel
3Reliability
If a new control channel is introduced for MTC devices in subbands, then subband device reception is enabled, but device complexity and implementation difficulty increase
Solution Approach 1:
The new control channel for MTC devices is designed to leverage existing EPDCCH structures and processing capabilities. By making the control channel multi-functional and compatible with existing device architecture, the system enables reliable subband reception without significantly increasing device complexity or implementation difficulty
Data Source
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AI summary
An embodiment of the present description provides a method for receiving a downlink control channel by a wireless device. The method can comprise a step for, when a wireless device receives configuration for repetition of a downlink control channel, determining a plurality of subframes for receiving the repetition of the downlink control channel. A special subframe, on the basis of particular TDD special subframe configuration, can be determined to be excluded from the receiving of the repetition of the downlink control channel. The method can comprise a step for receiving the repetition of the downlink control channel on the determined plurality of subframes from which the special subframe has been excluded.