SSB Pattern Design for Low PAPR in 5G mmWave DFT-s-OFDM

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Solution Overview

Problem

Current 3GPP New Radio specifications do not adequately address the design of Synchronization Signal Block (SSB) patterns and Physical Broadcast Channel (PBCH) to maintain a low Peak to Average Power Ratio (PAPR) for downlink transmissions using Discrete Fourier Transform spread Orthogonal Frequency Division Multiplexing (DFT-s-OFDM) at carrier frequencies above 52.6 GHz, necessitating a redesign for efficient power amplifier operation and phase noise handling.

Innovation Solution

The redesign includes specific SSB patterns and Demodulation Reference Signal (DMRS) designs for DFT-s-OFDM waveforms, employing time division multiplexing of PBCH and DMRS, and utilizing Zadoff-Chu, maximum length sequence, or Bjorck Constant Amplitude Zero Auto Correlation sequences for DMRS generation, tailored for frequencies above 52.6 GHz to manage PAPR and phase noise effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If DFT-s-OFDM is used for PBCH transmission at frequencies above 52.6 GHz, then PAPR is reduced and power amplifier efficiency is improved, but current 3GPP NR specifications do not provide adequate SSB pattern and PBCH design to maintain low PAPR

Engineering Contradiction:

ImprovePAPRVSAvoidSSB pattern design complexity

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The SSB is segmented into specific time-frequency patterns with defined structures for PSS, SSS, and PBCH components. The patent defines specific SSB patterns (e.g., 4-symbol, 8-symbol, 12-symbol patterns) that segment the transmission resources to maintain low PAPR while ensuring proper synchronization signal placement and PBCH coverage.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent changes key parameters including SSB duration (4, 8, or 12 symbols), subcarrier spacing (15, 30, 60, or 120 kHz), and cyclic prefix length to optimize PAPR performance for DFT-s-OFDM at mmWave frequencies. These parameter adjustments are specifically tailored for frequencies above 52.6 GHz to maintain low PAPR while ensuring reliable transmission.

Inventive Principle:

Principle #35Parameter changes

2Power

If DFT-s-OFDM is used for downlink transmissions above 52.6 GHz, then power amplifier operation is improved, but phase noise handling becomes more challenging

Engineering Contradiction:

Improvepower amplifier operationVSAvoidphase noise handling

Core Design Contradiction:

PowerVSReliability

Solution Approach 1:

The patent incorporates preliminary phase compensation mechanisms by designing SSB patterns that include reference signals and synchronization signals placed at specific positions to enable early phase noise estimation and compensation before data transmission. The DMRS is positioned to allow channel estimation that accounts for phase noise effects.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback mechanisms through DMRS and PT-RS that enable the receiver to estimate phase noise and feed back correction information to the transmitter. The SSB structure includes reference signals that provide feedback paths for phase noise compensation, improving reliability despite the challenges of mmWave operation.

Inventive Principle:

Principle #23Feedback

3Loss of energy

If SSB patterns are redesigned for frequencies above 52.6 GHz, then PAPR is reduced, but compatibility with existing NR specifications may be compromised

Engineering Contradiction:

ImprovePAPRVSAvoidspecification compatibility

Core Design Contradiction:

Loss of energyVSAdaptability or versatility

Solution Approach 1:

The patent designs SSB patterns that serve multiple functions: synchronization (PSS/SSS), broadcast information (PBCH), and channel estimation (DMRS). The same SSB structure is designed to work across different frequency ranges and DFT-s-OFDM configurations, providing universal compatibility while optimizing for low PAPR at mmWave frequencies.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent introduces dynamic SSB patterns that can be configured based on operating conditions. The SSB duration, subcarrier spacing, and resource allocation are made configurable to adapt to different scenarios, allowing the system to maintain low PAPR at mmWave frequencies while preserving compatibility with existing NR specifications through flexible parameter selection.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS11563610B2Synchronization signal block pattern and demodulation reference signal design for physical broadcast channel for channel frequencies above 52.6GHZ

Publication Date: 2023.01.24 INTEL CORP

AI summary

A device of a New Radio (NR) User Equipment (UE), a method and a machine readable medium to implement the method. The device includes a Radio Frequency (RF) interface, and processing circuitry coupled to the RF interface, the processing circuitry to: encode for transmission, to a User Equipment (UE), a Synchronization Signal Block (SSB) including a Physical Broadcast Channel (PBCH) and a channel estimation signal that is time division multiplexed with the PBCH, the channel estimation signal to allow the UE to estimate a channel for the PBCH and including one of a Secondary Synchronization Signal (SSS), a Demodulation Reference Signal (DMRS) or a Phase Tracking Reference Signal (PT-RS); and apply Discrete Fourier Transform-spread-Orthogonal Frequency Division Multiplexing (DFT-s-OFDM) to the PBCH prior to sending the SSB to the RF interface for transmission.