MAC CE Waveform Switching for Adaptive PUSCH Uplink Transmission
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Solution Overview
Problem
Existing wireless communication systems face challenges in efficiently switching between different PUSCH waveforms, such as CP-OFDM and DFT-s-OFDM, due to high signal overhead and latency in reconfiguration, which can cause service disruptions, especially for user equipment moving between cell edges and centers.
Innovation Solution
The implementation of a MAC CE mechanism for dynamically switching between CP-OFDM and DFT-s-OFDM waveforms, reducing latency and signaling overhead by using a MAC CE message instead of RRC signaling, with defined application times and DCI formats to ensure seamless waveform transitions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If RRC signaling is used to reconfigure PUSCH waveform, then waveform switching capability is achieved, but signaling overhead and reconfiguration latency increase
Solution Approach 1:
The patent introduces a MAC CE (Medium Access Control Control Element) as an intermediary mechanism between RRC signaling and physical layer waveform configuration. The MAC CE carries waveform indication information that enables faster waveform switching compared to traditional RRC reconfiguration, thereby reducing reconfiguration latency while maintaining waveform adaptability
Solution Approach 2:
The patent changes the parameter transmission layer from RRC (Radio Resource Control) to MAC CE (Medium Access Control Control Element). This parameter change in the signaling layer enables faster processing and reduced latency for waveform reconfiguration, as MAC CE operates at a lower layer with faster response time than RRC signaling
2Adaptability or versatility
If RRC signaling is used to reconfigure PUSCH waveform, then waveform switching capability is achieved, but signal overhead increases
Solution Approach 1:
The MAC CE acts as an intermediary that efficiently conveys waveform configuration information with reduced overhead compared to RRC signaling. The MAC CE format is optimized to carry essential waveform indication information in a compact manner, reducing the amount of signaling data required
Solution Approach 2:
The patent extracts only the essential waveform indication information from the full RRC reconfiguration message and transmits it via MAC CE. This extraction of critical parameters reduces signaling overhead while maintaining the necessary waveform switching capability, as only the waveform type indication is needed rather than complete reconfiguration parameters
3Adaptability or versatility
If waveform switching is implemented without proper timing coordination, then waveform adaptability improves, but service disruption increases
Solution Approach 1:
The patent implements preliminary action by defining a specific timing relationship between MAC CE reception and waveform application. The waveform indication in MAC CE becomes effective after a determined time offset, allowing the UE (User Equipment) to prepare for waveform switching in advance and ensure proper synchronization, thereby avoiding service disruption
Solution Approach 2:
The patent establishes feedback mechanisms through defined timing coordination where the network side controls the waveform switching timing via MAC CE transmission. This feedback loop ensures that waveform changes are coordinated between network and UE, maintaining service continuity while enabling waveform adaptability
Data Source
AI summary
Embodiments of the present application are related to methods and apparatuses of uplink transmission. An embodiment of the present application provides a user equipment (UE) including: a transceiver; and a processor coupled to the transceiver, wherein the processor is configured to: receive, via the transceiver a medium access control (MAC) control element (CE) at least indicating a waveform for physical uplink shared channel (PUSCH) transmissions in an activated bandwidth part (BWP); and transmit, via the transceiver a PUSCH in the activated BWP with the waveform in the case that the waveform is applicable for the PUSCH.