Dynamic PDCCH Waveform Selection for 52.6 GHz Power Efficiency

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Solution Overview

Problem

Current downlink control channel designs for frequencies above 52.6 GHz face challenges in power efficiency and multiplexing capacity due to high peak-to-average power ratio (PAPR) of single-carrier waveforms, limiting coverage and power amplifier efficiency, while legacy OFDM-based designs are not feasible for high PAPR control channels.

Innovation Solution

A system that dynamically selects between orthogonal frequency division multiplex (OFDM) and single-carrier (SC) waveforms for the physical downlink control channel (PDCCH) based on traffic conditions, allowing for power-efficient SC properties while maintaining legacy OFDM support for high throughput in favorable propagation conditions, using a scalable frame structure with common DMRS and REG structures for both waveforms.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If single-carrier waveform is used for PDCCH to improve power efficiency and coverage, then power amplifier efficiency and coverage are improved, but multiplexing capacity is drastically limited

Engineering Contradiction:
Improvepower amplifier efficiencyVSAvoidmultiplexing capacity
Core Design Contradiction:
Loss of energyVSProductivity

Solution Approach 1:

The system dynamically selects between SC and OFDM waveforms for PDCCH based on traffic conditions and propagation environment. The gNB can switch between SC waveform for power-efficient scenarios and OFDM waveform for high-multiplexing scenarios, making the system adaptable to different operational requirements rather than being fixed to a single waveform type.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the waveform parameter of PDCCH from a fixed OFDM design to a variable design that can be switched between SC and OFDM. This parameter change allows the system to optimize for either power efficiency or multiplexing capacity depending on the specific operational context, resolving the contradiction between these two opposing requirements.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If legacy OFDM-based PDCCH design is reused for above 52.6 GHz, then multiplexing capacity is maintained, but power efficiency and coverage are limited due to high PAPR

Engineering Contradiction:
Improvemultiplexing capacityVSAvoidpower efficiency
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The system transitions from a static legacy OFDM PDCCH design to a dynamic waveform selection mechanism that can switch between OFDM and SC. This allows the system to maintain the multiplexing capacity of OFDM when needed while being able to switch to SC for improved power efficiency, rather than being constrained to legacy OFDM alone.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The waveform parameter of PDCCH is changed from a fixed OFDM design to a variable design that can be switched between OFDM and SC waveforms. This parameter change enables the system to optimize power efficiency by selecting SC when appropriate, while still maintaining the ability to use OFDM for high multiplexing capacity scenarios.

Inventive Principle:
Principle #35Parameter changes

3Loss of energy

If SC waveform is used for PDCCH to achieve low PAPR, then power efficiency is improved, but the design complexity increases due to need for parallel OFDM support

Engineering Contradiction:
Improvepower efficiencyVSAvoidsystem complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The system is designed to support both SC and OFDM waveforms for PDCCH, making it universal and multi-functional. The gNB can select the appropriate waveform based on conditions, and the UE can monitor both types of PDCCH. This multi-functionality allows the system to achieve power efficiency through SC while maintaining compatibility and support for OFDM, rather than requiring a complete redesign.

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

Data Source

PatentEP3737025B1Downlink control channel arrangement for beyond 52.6 ghz
Publication Date: 2021.10.27 NOKIA TECHNOLOGIES OY
  • EP3737025B1 patent drawingFigure 1
  • EP3737025B1 patent drawingFigure 2
  • EP3737025B1 patent drawingFigure 3

AI summary

A method for a user equipment includes receiving a first configuration for a physical downlink control channel, where the first configuration has a first search space associated with a first control resource set. The method also includes receiving a second configuration for a physical downlink control channel, where the second configuration has a second search space associated with a second control resource set. Under the method, the user equipment monitors the physical downlink control channel according to the first and second configurations, and, when the physical downlink control channel is detected, determines a waveform for at least one time instant based on the configuration of the detected physical downlink control channel.