Uplink Waveform Switching for Faster Cell-Edge Coverage Adaptation
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Solution Overview
Problem
Current technologies face challenges in dynamically switching uplink waveforms between DFT-S-OFDM and CP-OFDM due to slow semi-static configuration via RRC signaling, which hinders effective coverage enhancement for user equipment at cell edges.
Innovation Solution
Implementing dynamic waveform switching through layer 1 or layer 2 signaling to indicate a target waveform, allowing quick adaptation between DFT-S-OFDM and CP-OFDM waveforms based on UE capability and network conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If semi-static configuration via RRC signaling is used for waveform switching, then configuration reliability is improved, but switching speed deteriorates
Solution Approach 1:
The patent applies dynamics by transitioning from static RRC configuration to dynamic waveform switching enabled by UL Grant DCI signaling. The base station can dynamically indicate waveform switching (DFT-S-OFDM or CP-OFDM) on a per-transmission basis, allowing the system to adapt to changing channel conditions and UE requirements in real-time, thus resolving the contradiction between configuration reliability and switching speed.
Solution Approach 2:
The patent segments the waveform configuration into two parts: semi-static RRC configuration that provides reliable baseline settings, and dynamic DCI-based indication that enables fast switching. This segmentation allows the system to maintain configuration reliability through RRC while achieving fast switching through selective DCI signaling, effectively resolving the technical contradiction.
2Speed
If dynamic waveform switching is implemented, then switching speed is improved, but device complexity increases
Solution Approach 1:
The patent applies universality by using the existing UL Grant DCI structure to serve multiple purposes: resource allocation, modulation and coding scheme indication, and waveform type indication. By multiplexing the waveform indication within the existing DCI format, the system achieves fast dynamic switching without adding significant complexity to the signaling structure or requiring separate dedicated signaling channels.
Solution Approach 2:
The patent changes the parameter of waveform indication from semi-static RRC configuration to dynamic DCI-based indication. This parameter change enables fast switching by allowing the base station to indicate the desired waveform (DFT-S-OFDM or CP-OFDM) in real-time based on current channel conditions, while managing device complexity through efficient use of existing signaling resources.
3Adaptability or versatility
If waveform switching is enabled for coverage enhancement, then coverage capability is improved, but signaling time increases
Solution Approach 1:
The patent applies periodic action by enabling waveform switching at specific transmission opportunities (per TBS or per slot) rather than requiring continuous reconfiguration. The base station can dynamically indicate waveform switching in UL Grants, allowing the UE to switch waveforms periodically based on changing coverage requirements, thus improving coverage capability while minimizing signaling time overhead.
Solution Approach 2:
The patent applies preliminary action by configuring waveform switching capability and parameters in advance through RRC signaling, while reserving the ability to dynamically adjust waveforms on-demand through DCI. This preliminary configuration establishes the framework for coverage enhancement, allowing fast dynamic switching when needed without requiring extensive real-time signaling, thus balancing coverage capability with signaling time efficiency.
Data Source
AI summary
Embodiments of the present disclosure relate to waveform indication and waveform switching. According to embodiments of the present disclosure, a baseband processor of user equipment (UE) is configured to perform operations comprising: receiving, using a transceiver of the UE, a waveform indication from a base station via layer 1 signaling or layer 2 signaling, the waveform indication indicating a target waveform, among a set of waveforms, to be used by the UE; and transmitting, using the transceiver of the UE, an uplink transmission to the base station based on the target waveform. In this way, dynamic waveform switching is achieved and coverage enhancement is provided.