Downlink Burst CSI Acquisition With Unified SRS-PDSCH Scheduling

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Solution Overview

Problem

The delay between SRS transmission and the corresponding PDSCH in downlink CSI acquisition is too long for timely and accurate CSI acquisition in future wireless communication systems, leading to suboptimal frequency and time domain allocation of SRS and CSI-RS with high DCI overhead.

Innovation Solution

Configuring and triggering DL bursts comprising SRS, CSI-RS, and PDSCH in a sequence optimized for timely DL CSI acquisition with low control overhead, where SRS resources are linked to PDSCH time-domain resource allocation, and frequency allocation is based on PDSCH FDRA, with adjustable PDSCH parameters via DCI.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If SRS and CSI-RS are separately scheduled/triggered by DCI with higher t/f domain flexibility, then PDSCH can be dynamically allocated, but DCI overhead increases

Engineering Contradiction:

Improvet/f domain flexibilityVSAvoidDCI overhead

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines SRS and CSI-RS scheduling into a unified DCI mechanism where a single DCI message triggers both SRS transmission and associated PDSCH reception. This merging reduces the number of separate DCI messages needed, thereby reducing DCI overhead while maintaining the ability to dynamically allocate resources in time and frequency domains.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The DCI message is designed to serve multiple functions simultaneously: it triggers SRS transmission, schedules PDSCH reception, and provides timing advance information. This multi-functionality allows the system to achieve flexible t/f domain allocation without proportionally increasing DCI overhead, as one control message accomplishes what previously required multiple separate messages.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Device complexity

If SRS transmission is performed far from PDSCH to allow processing time, then device complexity is reduced, but CSI acquisition timeliness deteriorates

Engineering Contradiction:

Improveprocessing timeVSAvoidCSI acquisition delay

Core Design Contradiction:

Device complexityVSLoss of time

Solution Approach 1:

The UE performs SRS transmission in advance of the PDSCH reception, with the SRS positioned in a preceding slot or symbol. This preliminary action allows the network to obtain CSI before the actual data transmission, enabling timely channel state information acquisition while maintaining sufficient processing time. The timing relationship is configured such that SRS occurs early enough for processing but close enough to be relevant for the upcoming PDSCH.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent introduces dynamic timing adjustment mechanisms where the time offset between SRS and PDSCH can be flexibly configured based on channel conditions, UE capability, and service requirements. This dynamic approach allows the system to optimize the balance between processing time and CSI timeliness, adjusting the SRS-PDSCH gap adaptively rather than using fixed timing relationships.

Inventive Principle:

Principle #15Dynamics

3Adaptability or versatility

If aperiodic SRS and CSI-RS are used for flexible scheduling, then t/f allocation is optimized, but DCI overhead increases

Engineering Contradiction:

Improvet/f allocation flexibilityVSAvoidDCI overhead

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent merges the scheduling of aperiodic SRS and CSI-RS into a unified DCI structure that triggers both reference signals and the associated PDSCH simultaneously. This combination reduces the number of separate DCI messages required compared to traditional approaches where SRS and CSI-RS are independently scheduled, thereby reducing overall DCI overhead while preserving aperiodic flexibility.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The DCI message contains embedded timing advance and resource allocation information that enables the UE to self-determine the appropriate SRS transmission timing and frequency resources without requiring separate RRC configuration or additional control signaling. This self-service approach reduces control overhead by allowing the UE to autonomously configure its reference signal transmission based on the DCI content.

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS20260101357A1Efficient low-latency CSI acquisition in a downlink burst

Publication Date: 2026.04.09 INTERDIGITAL PATENT HOLDINGS INC

AI summary

Methods and devices are disclosed for a wireless transmit receive unit (WTRU). The WTRU is configured with information including a downlink (DL) burst format table defining a plurality of DL burst formats. A DL burst format includes a time domain resource allocation (TDRA) of one or more physical downlink shared channels (PDSCHs), one or more sounding reference signal (SRS) resources and/or channel state information reference signal (CSI-RS) resources associated with the DL burst format. The WTRU may receive downlink control information (DCI) with a field indicating a select DL burst format from the DL burst format table that defines time domain positions of all signals associated with the select DL burst to the WTRU. The WTRU may then transmit SRS(s) and receive CSI-RS(s), if any, and one or more PDSCHs using the TDRA associated with the indicated select DL burst format. Additional embodiments are disclosed.