PUCCH SRI Mapping Using Orthogonal Resources to Cut Interference

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Solution Overview

Problem

Existing wireless cellular communication systems face challenges in efficiently multiplexing scheduling request indicator (SRI) signals in orthogonal frequency division multiple access (OFDMA) and single carrier frequency division multiple access (SC-FDMA) systems, particularly in scenarios with varying cell sizes and delay spreads, leading to reduced SRI capacity and increased interference.

Innovation Solution

A method for provisioning and allocating SRI resources on the physical uplink control channel (PUCCH) using a one-to-one mapping of logical SRI indices to physical resources, combined with cyclic shift and orthogonal covering sequences, to enhance SRI multiplexing capacity and reduce interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If traditional SRI multiplexing methods are used in OFDMA and SC-FDMA systems, then the system maintains basic scheduling request functionality, but the SRI multiplexing capacity is limited and interference increases in scenarios with varying cell sizes and delay spreads

Engineering Contradiction:

ImproveSRI multiplexing capacityVSAvoidinterference

Core Design Contradiction:

Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The patent extends SRI multiplexing from traditional single-dimension (time or frequency) approaches to multi-dimensional resource allocation by introducing cyclic shift and orthogonal covering sequence dimensions. This allows UEs to be multiplexed across multiple orthogonal dimensions simultaneously, dramatically increasing SRI capacity while maintaining orthogonality and reducing interference between users.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent dynamically adjusts SRI resource allocation parameters including cyclic shift values, orthogonal covering sequence lengths, and resource block assignments based on cell size, delay spread conditions, and traffic requirements. This adaptive parameter adjustment optimizes SRI multiplexing capacity for varying network conditions while minimizing interference through proper parameter selection.

Inventive Principle:

Principle #35Parameter changes

2Quantity of substance

If more UEs are multiplexed on the same resource blocks for SRI transmission, then SRI capacity increases, but collision probability and interference between UEs increase

Engineering Contradiction:

Improvenumber of UEs per RBVSAvoidcollision probability

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent segments the SRI transmission space into multiple orthogonal segments using cyclic shifts and orthogonal covering sequences. Each UE is assigned a unique combination of these segments, allowing many UEs to share the same resource blocks without collision. The segmentation creates isolated transmission paths that prevent interference even when UEs transmit simultaneously on the same RBs.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces cyclic shift and orthogonal covering sequence as intermediary elements between the physical resource blocks and the SRI signals. These intermediaries provide an additional layer of orthogonality that mediates between multiple UEs sharing the same RBs, enabling high-density multiplexing while maintaining signal distinguishability and reducing collision probability.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Adaptability or versatility

If fixed SRI resource allocation is used, then the system maintains simple resource management, but the network cannot efficiently adapt to varying cell sizes and delay spreads

Engineering Contradiction:

Improveadaptability to cell size and delay spreadVSAvoidresource allocation complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements dynamic SRI resource allocation where cyclic shift values, orthogonal covering sequence selections, and resource block assignments are adjusted in real-time based on network conditions including cell size, delay spread, and UE distribution. This dynamic adaptation allows the system to optimize SRI multiplexing for each specific scenario while the underlying orthogonal structure maintains manageable complexity through systematic resource assignment rules.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS20260040317A1Allocation and Logical to Physical Mapping of Scheduling Request Indicator Channel in Wireless Networks

Publication Date: 2026.02.05 TEXAS INSTRUMENTS INC

AI summary

A method for allocating resources for a scheduling request indicator (SRI) is disclosed. An SRI cycle period for use by user equipment (UE) within a cell is transmitted from a NodeB in a cell to UE within the cell. The NodeB transmits a specific SRI subframe offset and an index value to the particular UE within the cell. The specific SRI subframe offset and the index value enable the UE to determine a unique combination of cyclic shift, RS orthogonal cover, data orthogonal cover, and resource block number for the UE to use as a unique physical resource for an SRI in the physical uplink control channel (PUCCH).