Uplink Power Control via TPC-ID Masked CRC on PDCCH
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Solution Overview
Problem
In wireless communication systems, existing methods for transmitting transmit power control (TPC) commands on the physical downlink control channel (PDCCH) are inefficient due to the large size of the PDCCH compared to the small size of the TPC command, leading to ineffective use of radio resources, especially when TPC commands are transmitted alone without resource allocation information.
Innovation Solution
A method where a TPC identifier (TPC-ID) is masked with cyclic redundancy checksum (CRC) parity bits and transmitted on the PDCCH, allowing multiple TPC commands to be conveyed efficiently, enabling the UE to adjust uplink channel transmit power and mitigate interference and battery consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If TPC commands are transmitted on PDCCH with resource allocation information, then power control functionality is achieved, but radio resources are used inefficiently due to large PDCCH size relative to small TPC command size
Solution Approach 1:
The patent extracts the TPC command transmission from the combined PDCCH structure and places it on a separate dedicated physical control channel. This separation allows the TPC command to be transmitted with minimal overhead without requiring the full PDCCH structure with resource allocation information, thereby improving radio resource efficiency while maintaining power control functionality.
Solution Approach 2:
The control channel is segmented into separate dedicated physical control channels for TPC commands and separate channels for resource allocation information. This segmentation allows independent optimization of each channel's size and content, enabling efficient TPC transmission without unnecessary PDCCH overhead.
2Loss of energy
If TPC command is transmitted alone without resource allocation information, then radio resource usage is improved, but the TPC command cannot be transmitted when neither downlink nor uplink resource allocation information is transmitted
Solution Approach 1:
The dedicated physical control channel is designed to carry TPC commands independently of resource allocation information transmission. This multi-functional approach ensures that TPC commands can be transmitted in all scenarios - whether resource allocation information is present or not - thereby improving transmission reliability while maintaining radio resource efficiency.
3Loss of information
If PDCCH size is large to carry both resource allocation and TPC commands, then complete control information is transmitted, but the size mismatch leads to ineffective radio resource usage
Solution Approach 1:
The TPC command is extracted from the large PDCCH structure and transmitted on a dedicated control channel with appropriate size. This extraction eliminates the size mismatch problem, allowing complete TPC command transmission without the overhead of resource allocation information, thereby improving radio resource efficiency while maintaining control information completeness.
Solution Approach 2:
The control information is segmented into separate dedicated channels - one for TPC commands and another for resource allocation information. This segmentation allows each channel to be optimally sized for its specific purpose, avoiding the waste of transmitting large PDCCH structures when only small TPC commands need to be conveyed.
Data Source
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AI summary
A method of controlling a transmit power of an uplink channel is provided. Downlink control information of which Cyclic Redundancy Check (CRC) parity bits are masked with a TPC identifier is received on a downlink control channel. The transmit power of the uplink channel is adjusted based on a TPC command in the downlink control information.