Uplink Control Channel Multiplexing Using Block Spreading Codes

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Solution Overview

Problem

In mobile communication systems, existing methods for multiplexing uplink control channels from multiple user equipment (UE) using FDM or CDM methods lead to reduced bandwidth per user, increased interference, and frequent changes in transmission bandwidth, which degrade signal quality and increase signaling overhead.

Innovation Solution

Implementing a single carrier method with persistent scheduling and block spreading codes to ensure a higher number of orthogonal code sequences, reducing the frequency of bandwidth changes and maintaining orthogonality among user signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If FDM or CDM methods are used to multiplex uplink control channels from multiple user equipment, then multiple users can share the bandwidth, but the bandwidth per user is reduced and interference increases

Engineering Contradiction:
Improvenumber of multiplexed usersVSAvoidbandwidth per user
Core Design Contradiction:
Quantity of substanceVSArea of stationary object

Solution Approach 1:

The system segments the uplink control channel resources by separating persistent scheduling users (who transmit control information periodically) from dynamic scheduling users. This segmentation allows persistent scheduling users to be assigned dedicated time-frequency resources with guaranteed bandwidth, while other users share remaining resources, thereby resolving the contradiction between supporting multiple users and maintaining sufficient bandwidth per user.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a new dimension of resource allocation by adding a dedicated control region in the frequency domain specifically for persistent scheduling users. Instead of competing for the same uplink data channel resources, these users are allocated separate resources, effectively adding a new resource dimension that increases overall system capacity without reducing individual user bandwidth.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Adaptability or versatility

If transmission bandwidth is frequently changed to accommodate varying numbers of multiplexed users, then resource allocation flexibility improves, but signaling overhead increases and transmission efficiency decreases

Engineering Contradiction:
Improveresource allocation flexibilityVSAvoidsignaling overhead
Core Design Contradiction:
Adaptability or versatilityVSLoss of information

Solution Approach 1:

The system performs preliminary allocation of dedicated time-frequency resources for persistent scheduling users at the beginning of each radio frame. This advance allocation eliminates the need for frequent bandwidth reconfiguration signaling, as these users' resources are predetermined and remain stable throughout the frame, thereby reducing signaling overhead while maintaining allocation flexibility for other users.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the allocation parameters from dynamic per-user bandwidth assignment to a hybrid approach where persistent scheduling users receive fixed parameter assignments (dedicated control region), while other users receive dynamic assignments. This parameter change stabilizes the resource allocation structure, reducing the frequency of bandwidth changes and associated signaling overhead.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If dedicated frequency bandwidth is allocated for uplink control channel transmission when no uplink data channel is transmitted, then control information can be transmitted independently, but the number of orthogonal code sequences decreases

Engineering Contradiction:
Improvecontrol channel transmission reliabilityVSAvoidnumber of orthogonal code sequences
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the uplink control channel transmission with the uplink data channel transmission by allowing persistent scheduling users to transmit control information (ACK/NACK, CQI) within the same time-frequency resources as their data transmissions. This merging approach maintains a sufficient number of orthogonal code sequences for multiplexing multiple users while ensuring reliable control information transmission, as the control information is embedded in the data channel rather than requiring separate dedicated resources.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP2104239B1User equipment and method
Publication Date: 2018.08.08 NTT DOCOMO INC
  • EP2104239B1 patent drawingFigure 1
  • EP2104239B1 patent drawingFigure 2
  • EP2104239B1 patent drawingFigure 3

AI summary

User equipment that is capable of transmitting at least an uplink control channel to a base station apparatus using a single carrier method and to which persistent scheduling is applied, the user equipment includes a unit providing data arrival acknowledgement information, a unit providing channel quality information, a control channel generation unit generating an uplink control channel including at least one of the data arrival acknowledgement information or the channel quality information, and a transmission unit transmitting the uplink control channel using a predetermined dedicated bandwidth, in which the uplink control channel includes at least one unit block including a sequence in which a same factor reported using an upper-layer signaling is multiplied to each chip of an orthogonal code sequence for the user equipment.