SRS Switching via UpPTS PRACH Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current wireless communication systems face challenges in efficiently managing SRS switching and PRACH transmissions, particularly in scenarios where UEs are configured with multiple component carriers, leading to interruptions and reduced throughput due to the need for timing advance and power control mechanisms that are not effectively integrated with existing random access procedures.
Innovation Solution
The implementation of enhanced techniques for SRS switching and PRACH transmissions, including the use of the beginning symbols of UpPTS for PRACH transmission and modified random access procedures to minimize interruptions, along with group DCI for joint triggering and power control of SRS transmissions across multiple component carriers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the UE transmits PRACH on a downlink CC to obtain timing advance for SRS transmission, then the UE can acquire valid timing advance for SRS transmission, but communication on another CC is interrupted causing reduced throughput
Solution Approach 1:
The patent segments the PRACH transmission into two separate phases: first transmitting PRACH on an uplink CC to obtain timing advance, then switching to the downlink CC for SRS transmission. This segmentation eliminates the need to interrupt uplink CC communication for PRACH transmission on downlink CC, thereby resolving the throughput reduction issue while maintaining timing advance validity.
Solution Approach 2:
The patent performs the timing advance acquisition action in advance by transmitting PRACH on an uplink CC before switching to the downlink CC for SRS transmission. This preliminary action ensures that the UE has valid timing advance information ready before attempting SRS transmission on the downlink CC, eliminating the need to interrupt ongoing uplink communications.
2Adaptability or versatility
If the UE switches between CCs for SRS transmission, then the UE can transmit SRS on downlink CCs to exploit channel reciprocity, but communication on the original CC is interrupted
Solution Approach 1:
The patent segments the SRS transmission process by first acquiring timing advance on an uplink CC, then switching to the downlink CC for SRS transmission. This segmentation allows the UE to maintain uplink communication on the original CC while performing SRS transmission on the downlink CC, thereby reducing interruptions and maintaining throughput.
Solution Approach 2:
The patent introduces an intermediary uplink CC as a bridge for timing advance acquisition. Instead of directly switching from one downlink CC to another for SRS transmission, the UE uses an uplink CC as an intermediary to first obtain timing advance information, making the SRS transmission process more efficient and less disruptive to ongoing communications.
3Reliability
If multiple PRACH transmissions are performed for SRS switching, then the UE can ensure successful timing advance acquisition, but interruptions to other CC communication increase significantly
Solution Approach 1:
The patent segments the random access procedure by performing PRACH transmission on an uplink CC rather than on a downlink CC. This segmentation allows the UE to complete timing advance acquisition without interrupting downlink CC communications, significantly reducing communication interruption time while ensuring successful timing advance acquisition.
Solution Approach 2:
The patent performs the timing advance acquisition action in advance on an uplink CC before switching to the downlink CC for SRS transmission. This preliminary action ensures that all necessary timing advance information is obtained before interrupting any downlink CC communications, minimizing the total interruption time while ensuring successful timing advance acquisition.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Certain aspects of the disclosure relate to techniques and apparatus for improving random access for SRS switching in a wireless network. Prior to transmitting a SRS, a UE may interrupt communication on a first carrier to switch from the first carrier to a second carrier to transmit a PRACH. To reduce interruption to the first carrier, the UE may use the beginning symbol(s) of a UpPTS on the second carrier to transmit the PRACH. In addition, to reduce interruption to the first carrier, the UE may monitor for another PDCCH order before transmitting another PRACH. Further, aspects of the present disclosure provide techniques and apparatus for jointly triggering SRS transmissions and performing power control for SRS transmissions. A BS may trigger SRS transmissions from multiple UEs, trigger SRS transmissions from multiple carriers from the same UE at the same time and/or perform power control separately for each carrier.