Terminal Device Antenna Selection for Carrier Aggregation
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Solution Overview
Problem
Current radio communication systems in LTE face inefficiencies in managing uplink control channels and reference signals, particularly in multi-cell scenarios with carrier aggregation, leading to increased complexity and resource utilization challenges.
Innovation Solution
The implementation of adaptive CRC parity bit management and antenna selection mechanisms in terminal and base station devices, allowing for efficient communication by adjusting the number of CRC parity bits and antenna ports based on specific conditions, such as the number of serving cells and RNTI configurations, to enhance channel decoding and resource allocation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the number of serving cells is increased for carrier aggregation, then the data transmission capacity is improved, but the complexity of managing uplink control channels and reference signals increases
Solution Approach 1:
The patent segments the uplink control channel management by introducing separate PUCCH groups, where each group is associated with specific serving cells. This allows the terminal to manage uplink control information for multiple cells in an organized manner, reducing the overall complexity while maintaining high data transmission capacity through carrier aggregation.
Solution Approach 2:
The patent introduces a new dimension of organization by grouping serving cells into PUCCH groups and associating reference signals with specific groups. This dimensional organization (cell groups rather than individual cells) simplifies the management of uplink control channels and reference signals while supporting carrier aggregation across multiple cells.
2Productivity
If multiple antenna ports are configured for MIMO transmission, then the data rate is improved, but the complexity of RF configurations in terminal devices increases
Solution Approach 1:
The patent implements dynamic antenna port selection where the terminal determines which antenna ports to use based on the PUCCH group associated with the PDSCH. This dynamic adaptation allows the system to achieve high data rates through MIMO when needed while reducing RF configuration complexity by not requiring all antenna ports to be actively configured simultaneously.
Solution Approach 2:
The patent changes the parameter of antenna port configuration from a static all-or-nothing approach to a dynamic group-based approach. The antenna port configuration parameter is adjusted based on the PUCCH group association, allowing the system to optimize between data rate and complexity by selectively activating antenna ports based on current transmission requirements.
3Reliability
If CRC parity bits are extended for better error detection, then the reliability of channel decoding is improved, but the overhead and resource usage increase
Solution Approach 1:
The patent applies local quality by using 24-bit CRC for PDCCH (higher reliability needed for control channels) and 16-bit CRC for PDSCH (data channels where some errors can be corrected by higher layers). This differentiated CRC length based on local requirements optimizes the balance between reliability and overhead for different channel types.
Data Source
Figure 1
Figure 2A~2B
Figure 2C
AI summary
A terminal device is provided such that in a case that closed-loop UE transmit antenna selection is configured, a bit sequence is given by scrambling CRC parity bits with an RNTI and an antenna selection mask, in a case that the number of the CRC parity bits is a first value, a first transmit antenna port is given by a first antenna selection mask, and in a case that the number of the CRC parity bits is a second value, the first transmit antenna port is given by a second antenna selection mask that is different from the first antenna selection mask.