TDD Subframe Configuration for WTRU Coverage Enhancement
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Solution Overview
Problem
In wireless systems, the limitations in repeating subframes and channels for coverage enhancement mode restrict the effectiveness of data transmission, particularly in Time Division Duplex (TDD) configurations where subframe configurations may not be readily available for WTRUs.
Innovation Solution
A wireless transmit/receive unit (WTRU) operating in coverage enhanced mode determines specific subframes for receiving and transmitting repeated signals based on received TDD subframe configurations, allowing for efficient repetition of Physical Downlink Shared Channel (PDSCH) and Physical Uplink Shared Channel (PUSCH) signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If subframe configurations are not readily available for WTRUs in TDD systems, then coverage enhancement through signal repetition is limited, but system complexity and configuration management become more difficult
Solution Approach 1:
The patent applies preliminary action by pre-configuring TDD uplink-downlink configurations and determining which subframes can be used for signal repetition before actual coverage enhancement is needed. The WTRU receives and stores multiple TDD configurations in advance, identifying suitable subframes for repetition ahead of time, so that when coverage enhancement is required, the WTRU can immediately utilize the pre-identified subframes without additional complexity.
2Reliability
If signal repetition is implemented in TDD systems with limited subframe availability, then data transmission reliability improves, but transmission efficiency and throughput may deteriorate
Solution Approach 1:
The patent applies dynamics by enabling the WTRU to adaptively select from multiple pre-configured TDD uplink-downlink configurations based on current channel conditions and coverage requirements. The WTRU can dynamically determine which configuration and corresponding subframes to use for signal repetition, allowing the system to optimize between reliability and efficiency depending on the operational context rather than being fixed to a single configuration.
Solution Approach 2:
The patent applies parameter changes by allowing the WTRU to receive and switch between different TDD configuration parameters (uplink-downlink configurations) that define which subframes are available for repetition. By changing these configuration parameters based on channel quality and coverage needs, the system can adjust the degree of signal repetition to achieve the desired balance between reliability improvement and transmission efficiency.
Data Source
AI summary
A wireless transmit/receive unit (WTRU) may receive a first time division duplex (TDD) uplink (UL)/downlink (DL) configuration information via system information. Also, the WTRU may receive second TDD UL/DL configuration information via dedicated radio resource control (RRC) signaling. Further, the WTRU may receive third TDD UL/DL configuration information via downlink control information (DCI). The WTRU may transmit a physical uplink shared channel (PUSCH) transmission. Moreover, the WTRU may transmit at least one PUSCH repetition transmission in a time interval indicated as a UL time interval in at least one of the first TDD UL/DL configuration information, the second TDD UL/DL configuration information, or the third TDD UL/DL configuration information. In an example, the system information may be a system information block (SIB), such as a SIB1.