Barker Sequence Mapping for Low PAPR in Wireless Subcarriers

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Solution Overview

Problem

In new-generation wireless communications systems, transmitting a signal on two inconsecutive resource blocks in one slot disrupts the low peak-to-average power ratio (PAPR) characteristic, leading to a high PAPR and loss of frequency domain diversity gain.

Innovation Solution

The method involves mapping a sequence into subcarrier groups with a Barker sequence structure, ensuring that the first element starts from a subcarrier group with a larger number and ends at a subcarrier group with a smaller number, maintaining a low PAPR and achieving frequency domain diversity by using inconsecutive subcarrier groups.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If frequency-domain frequency hopping is performed in a same timeslot by transmitting a same signal on two inconsecutive resource blocks, then frequency domain diversity gain can be obtained, but the low peak-to-average power ratio characteristic is damaged and high PAPR is caused

Engineering Contradiction:
Improvefrequency domain diversity gainVSAvoidpeak-to-average power ratio
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent applies asymmetry by using a Barker sequence with a specific asymmetric structure where the first element starts from a subcarrier group with a larger number and ends at a subcarrier group with a smaller number. This asymmetric mapping pattern allows the signal to hop between inconsecutive subcarrier groups while maintaining low PAPR characteristics, thus resolving the contradiction between obtaining frequency diversity and avoiding high PAPR.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The patent changes the parameter of sequence mapping order by using a Barker sequence structure that maps elements in a specific pattern across subcarrier groups. By changing how the sequence elements are mapped (from conventional sequential mapping to Barker sequence-based mapping), the system achieves both frequency domain diversity through inconsecutive resource block usage and maintains low PAPR characteristics.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If a same signal is transmitted on inconsecutive resource blocks to ensure flexibility of resource allocation, then resource allocation flexibility is improved, but low PAPR characteristic is damaged and high PAPR is caused

Engineering Contradiction:
Improveresource allocation flexibilityVSAvoidpeak-to-average power ratio
Core Design Contradiction:
Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The patent changes the mapping parameter from conventional sequential mapping to Barker sequence-based mapping, enabling flexible resource allocation across inconsecutive subcarrier groups while maintaining low PAPR. The Barker sequence structure allows the system to adaptively allocate resources without suffering from high PAPR issues.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent inverts the conventional mapping approach by using a Barker sequence where the first element corresponds to a subcarrier group with a larger number and subsequent elements map to subcarrier groups with smaller numbers. This inverted mapping pattern enables flexible resource allocation while preserving the low PAPR characteristic that would otherwise be lost with conventional mapping methods.

Inventive Principle:
Principle #13The other way round (Inversion)

Data Source

PatentEP3550779B1Signal sending and receiving method and apparatus
Publication Date: 2021.04.07 HUAWEI TECH CO LTD
  • EP3550779B1 patent drawingFigure 1~2
  • EP3550779B1 patent drawingFigure 3
  • EP3550779B1 patent drawingFigure 4~5

AI summary

A signal sending method and apparatus, and a signal receiving method and apparatus are provided, to ensure a low peak-to-average power ratio and a frequency domain diversity gain when a signal is sent on two different subcarrier groups in a same time cell. The method includes: mapping, by a transmit end, a first sequence {pia0,pia1,...,piaP-1} whose length is P into an ith subcarrier group in M subcarrier groups in a same time cell, where the ith subcarrier group includes K consecutive subcarriers that are evenly distributed, M, P, and K are all greater than or equal to 2, P≤K, there is at least one pair of two inconsecutive subcarrier groups in the M subcarrier groups, and a second sequence {pi} corresponding to the M subcarrier groups meets the following requirement: A sequence {xi} is a Barker sequence, where {xi} = {xi | x1 = ps+1,x2 = ps+2,...,xM-s = pM,xM-s+1 = p1,xM-s+2 = p2,...,xM = ps}, or a sequence {cxi} is a second sequence corresponding to M consecutive subcarrier groups, where c is a non-zero complex number; generating, by the transmit end, a sending signal based on signals on subcarriers in the ith subcarrier group; and sending, by the transmit end, the sending signal.