Uplink Control Channel Multiplexing for 5G Reliability

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Solution Overview

Problem

Future radio communication systems face challenges in properly receiving control information due to differences in subframe configurations and multiplexing methods compared to existing LTE systems, leading to potential errors in UCI transmission and increased PAPR.

Innovation Solution

The solution involves associating predetermined parameters such as phase rotation and base sequences with control information to implicitly report UCI by generating RSs, allowing for UCI transmission without frequency-division-multiplexing with RSs, even in minimal one-symbol configurations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If UCI and RSs are allocated to different symbols in a subframe using existing PUCCH formats, then UCI and RSs can be transmitted simultaneously, but the UL control channel requires more symbols and frequency hopping resources

Engineering Contradiction:
ImproveUCI transmission reliabilityVSAvoidUL control channel configuration complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines UCI and RS into a single symbol by frequency-division multiplexing them within the same time resource. This merging approach eliminates the need for separate symbol allocation and reduces the overall control channel resource requirements while maintaining reliable transmission of both UCI and RS.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent transitions from time-division multiplexing (separate symbols) to frequency-division multiplexing (different frequencies within the same symbol). This dimensional change allows UCI and RS to coexist in the same time resource without interfering with each other, thereby reducing the number of symbols needed.

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

2Loss of time

If a UL control channel with fewer symbols is used in future radio communication systems, then latency is reduced and power consumption is lowered, but proper reporting of control information becomes difficult

Engineering Contradiction:
ImproveUCI transmission latencyVSAvoidControl information reporting accuracy
Core Design Contradiction:
Loss of timeVSReliability

Solution Approach 1:

The patent uses frequency-division multiplexing within a single symbol to accommodate both UCI and RS, enabling compact one-symbol control channels that reduce latency while maintaining reliable control information reporting through proper frequency domain separation.

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

Solution Approach 2:

The patent changes the multiplexing parameter from time-domain separation to frequency-domain separation, allowing UCI and RS to be transmitted simultaneously within a reduced one-symbol structure, thereby achieving both low latency and reliable reporting.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If frequency-division multiplexing is applied to UCI and RS in one symbol, then resource efficiency is improved, but PAPR increases

Engineering Contradiction:
ImproveResource utilization efficiencyVSAvoidPAPR
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent applies different modulation schemes to different parts of the signal: DFT-S-OFDM for UCI to maintain low PAPR, and OFDM for RS to achieve frequency-division multiplexing. This local quality differentiation allows resource-efficient multiplexing while controlling PAPR in the critical UCI portion.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent dynamically selects the modulation scheme based on the signal type: using DFT-S-OFDM for UCI when low PAPR is critical, and OFDM for RS when frequency-division multiplexing is needed. This dynamic approach balances resource efficiency and PAPR control.

Inventive Principle:
Principle #15Dynamics

4Object-generated harmful factors

If DFT-S-OFDM is used in the UL, then PAPR is reduced compared to OFDM, but frequency-division multiplexing capability is limited

Engineering Contradiction:
ImprovePAPRVSAvoidFrequency-division multiplexing capability
Core Design Contradiction:
Object-generated harmful factorsVSAdaptability or versatility

Solution Approach 1:

The patent merges DFT-S-OFDM and OFDM into a hybrid structure where DFT-S-OFDM handles UCI transmission with low PAPR, and OFDM handles RS transmission with frequency-division multiplexing capability. This combination allows the system to benefit from both modulation schemes simultaneously.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent creates a universal UL transmission structure that can handle both low-PAPR requirements (via DFT-S-OFDM for UCI) and frequency-division multiplexing requirements (via OFDM for RS) within the same uplink channel, making the system adaptable to multiple transmission needs.

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

Data Source

PatentEP3537676B1Transmission device and radio communication method
Publication Date: 2022.09.07 NTT DOCOMO INC
  • EP3537676B1 patent drawingFigure 1A~1B
  • EP3537676B1 patent drawingFigure 2A~2B
  • EP3537676B1 patent drawingFigure 3A~3C

AI summary

The present invention is designed so that control information for a receiving apparatus can be reported properly in the UL/DL of future radio communication systems. A transmitting apparatus, according to the present invention, has a control section that controls generation of a reference signal using an amount of phase rotation and/or a base sequence that are associated with control information for a receiving apparatus, and a transmission section that transmits the reference signal.