Uplink Cyclic Shift Selection for Implicit Signaling

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Solution Overview

Problem

Current wireless communication systems, particularly in LTE, face challenges in efficiently utilizing unused uplink sequence shifts for signaling, which limits the ability to convey additional information and optimize resource allocation, especially in scenarios with partial loading or dominant interference.

Innovation Solution

The method involves selecting and using unused cyclic shifts or orthogonal cover codes to implicitly convey information, allowing user equipment (UE) to signal various parameters such as interference conditions, antenna configurations, and channel state information to the base station, thereby optimizing resource usage and reducing signaling overhead.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional LTE design focuses on spectral efficiency and QoS improvement, then high-end device performance is enhanced, but the ability to support low-cost devices and utilize unused resources for additional signaling is limited

Engineering Contradiction:
ImproveQoS supportVSAvoidsupport for low-cost devices
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent makes unused uplink cyclic shifts serve multiple functions: their original purpose for maintaining orthogonality among multiple users and a new function for conveying uplink signaling information. This multi-functionality allows the system to support both high-end devices with full signaling capabilities and low-cost devices that can utilize implicit signaling through cyclic shift selection, thereby resolving the contradiction between reliability/QoS improvement and adaptability to low-cost devices.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Loss of information

If explicit signaling is used to convey uplink information, then information transmission is direct and reliable, but signaling overhead increases and resource efficiency decreases

Engineering Contradiction:
Improvesignaling accuracyVSAvoidsignaling overhead
Core Design Contradiction:
Loss of informationVSLoss of energy

Solution Approach 1:

The patent merges the uplink signaling information with the existing uplink transmission by embedding it in the selection of cyclic shifts for physical uplink shared channel (PUSCH) or physical uplink control channel (PUCCH). Instead of separate explicit signaling, the cyclic shift selection itself carries the information, combining data transmission and control signaling into a single operation. This reduces signaling overhead and resource consumption while maintaining information transmission accuracy, resolving the contradiction between signaling accuracy and signaling overhead.

Inventive Principle:
Principle #5Merging (Combining)

3Device complexity

If unused cyclic shifts are left unutilized, then resource allocation is simple, but system capacity and information conveying capability are limited

Engineering Contradiction:
Improveresource allocation complexityVSAvoidsystem capacity
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent enables the unused cyclic shifts to serve themselves by having them automatically convey uplink signaling information through their selection. The base station simply needs to indicate which cyclic shifts are available for signaling purposes, and the user equipment autonomously selects appropriate cyclic shifts to convey its uplink information. This self-service mechanism increases system capacity and information conveying capability without significantly increasing resource allocation complexity, as the existing cyclic shift management framework is leveraged rather than creating a completely new signaling mechanism.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP2987259B1Utilizing unused uplink cyclic shifts for signaling background
Publication Date: 2021.08.18 QUALCOMM INC
  • EP2987259B1 patent drawingFigure 1
  • EP2987259B1 patent drawingFigure 2
  • EP2987259B1 patent drawingFigure 2A

AI summary

Certain aspects of the present disclosure propose methods and apparatus for signaling information via the selection of resources used for an uplink transmission. The aspects may include selecting one or more cyclic shifts or orthogonal cover codes used to transmit an uplink channel. The one or more cyclic shifts or orthogonal cover codes may be selected to convey information. The information may be conveyed by transmitting the uplink channel using the selected cyclic shifts or orthogonal cover codes.