MTC UE Extended Coverage Access Interference Control
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Solution Overview
Problem
Low-cost MTC devices with a single receive antenna cause interference to neighboring cells when attempting extended coverage access, as they may not support extended coverage techniques, leading to interference issues for adjacent cells.
Innovation Solution
Implement mechanisms in MTC UEs to detect neighboring cells' capabilities for extended coverage and refrain from using extended coverage access if the neighboring cells do not support it, by reading physical cell indicators, system information blocks, and evaluating reference signal received power to prevent excessive interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If MTC UEs transmit PRACH at high power for extended periods to gain initial access in poor radio conditions, then extended coverage is achieved, but interference to neighboring cells increases significantly
Solution Approach 1:
The MTC UE performs preliminary detection of neighboring cell capabilities before initiating extended coverage access. By reading physical cell indicators and system information blocks in advance, the device determines whether neighboring cells support extended coverage, preventing harmful high-power transmissions before they occur
Solution Approach 2:
The system implements feedback mechanisms where MTC UEs monitor and detect neighboring cell capabilities through system information blocks. This feedback information is used to adjust access behavior, allowing extended coverage transmission only when neighboring cells are confirmed to support it
2Ease of manufacture
If MTC UEs use single receive antenna design to reduce device cost, then device cost and power consumption are reduced, but downlink coverage range is limited
Solution Approach 1:
The patent changes operational parameters of the MTC UE, specifically adjusting transmission power levels and timing for PRACH transmissions. By transmitting at higher power for extended durations and utilizing coverage enhancement modes, the single-antenna device achieves extended coverage comparable to multi-antenna devices
3Ease of operation
If MTC UEs attempt extended coverage access in cells not capable of supporting it, then access attempts are made in poor radio conditions, but excessive interference is caused to adjacent cells
Solution Approach 1:
Before attempting extended coverage access, the MTC UE performs preliminary detection by reading physical cell indicators and system information blocks to verify neighboring cell capabilities. This preliminary action prevents access attempts in incompatible cells, avoiding interference before it occurs
Solution Approach 2:
System information blocks serve as an intermediary mechanism that conveys neighboring cell capability information to MTC UEs. This intermediary allows devices to make informed access decisions without directly causing interference to incompatible cells
Data Source
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AI summary
Improved mechanisms for wireless cellular access using coverage extension techniques are described. A UE needing to use coverage extension to request access to a prospective serving cell detects cells (other than the prospective serving cell) on its frequency, and then investigates each such cell (for example, by attempting to read its system information block and, if the system information block can be read, determining if the cell supports access using coverage extension. If detected cells do not support coverage extension, the UE does not use coverage extension techniques to request access, but if all detected cells support coverage extension, the UE requests access using coverage extension techniques.