SA Preamble PAPR Reduction via Block Cover Sequences

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Solution Overview

Problem

The high Peak to Average Power Ratio (PAPR) of Secondary Advanced (SA) preambles in Orthogonal Frequency Division Multiplexing (OFDM) wireless communication systems, particularly in IEEE 802.16m standards, poses challenges for efficient transmission and identification of cell identifiers, leading to power inefficiencies and interference issues.

Innovation Solution

The implementation of a Block Cover Sequence (BCS) designed for SA preambles, applied to each subblock, reduces PAPR by modifying bit values and using Tone Dropping (TD) to maintain consistent subcarrier intervals across varying frequency bands, thereby optimizing power distribution and reducing interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If OFDM scheme is used for high speed mobile communication, then data transmission capability is improved, but Peak to Average Power Ratio (PAPR) increases

Engineering Contradiction:
Improvedata transmission capabilityVSAvoidPower to Average Power Ratio (PAPR)
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The SA preamble sequence is divided into multiple subblocks, and a Block Cover Sequence (BCS) is applied to each subblock independently. This segmentation allows for localized PAPR reduction while maintaining the overall structure and identification capability of the preamble.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention modifies the bit values within each subblock by applying a BCS, which changes the amplitude parameters of the OFDM signal. This parameter modification reduces the peak power while preserving the essential synchronization and identification functions.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If SA preamble is transmitted for BS identification, then cell IDentifier (ID) distinction is improved, but PAPR increases causing power inefficiency

Engineering Contradiction:
ImproveBS identification accuracyVSAvoidpower efficiency
Core Design Contradiction:
Measurement precisionVSLoss of energy

Solution Approach 1:

The preamble structure is segmented into subblocks with BCS applied to each, enabling energy-efficient transmission while preserving the unique identification characteristics of each cell through the maintained subblock structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different BCS patterns can be applied to different subblocks, allowing local optimization of power efficiency while maintaining the global identification function. Each subblock can be independently optimized without affecting the overall BS identification capability.

Inventive Principle:
Principle #3Local quality

3Adaptability or versatility

If Tone Dropping (TD) is used to maintain consistent subcarrier intervals, then frequency band adaptability is improved, but system complexity increases

Engineering Contradiction:
Improvefrequency band adaptabilityVSAvoidsystem complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The BCS application method works universally across different frequency bands and OFDM configurations. The same subblock segmentation and BCS application procedure can be used regardless of the specific frequency band or subcarrier interval, providing a universal solution that adapts to various system configurations without requiring complex band-specific processing.

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

Data Source

PatentEP2267964B1Apparatus and method for transmitting preamble in a wireless communication system
Publication Date: 2021.01.20 SAMSUNG ELECTRONICS CO LTD
  • EP2267964B1 patent drawingFigure 1
  • EP2267964B1 patent drawingFigure 2
  • EP2267964B1 patent drawingFigure 3

AI summary

An apparatus and method for reducing a Peak to Average Power Ratio (PAPR) of a Secondary Advanced (SA) preamble in a wireless communication system are provided. A method for transmitting an SA preamble includes determining an SA preamble, constructed in a unit of subblocks, according to a frequency band to be used for transmitting information, determining a sequence for reducing a PAPR of the SA preamble in consideration of at least one of a frequency band, a segment IDentifier (ID), and the number of antennas transmitting the SA preamble, updating the SA preamble using the determined sequence, and transmitting the updated SA preamble to a receive end.