Pre-mapping Unit for SC-FDMA Multiple-Antenna Signal Processing

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Solution Overview

Problem

Current multiple-antenna signal processing systems in SC-FDMA systems face challenges in maintaining low Peak Average Power Ratio (PAPR) while achieving high diversity and multiplexing gains, as non-linear multiple-antenna processing disrupts data linearity and affects PAPR characteristics.

Innovation Solution

A pre-mapping processing unit is introduced to map input data streams before the DFT processing, allowing for pre-mapping based on the current multiple-antenna processing mode, which minimizes linearity destruction and maintains PAPR characteristics by performing specific mapping modes such as CDD, weighting, or interleaving, thereby enabling larger diversity and multiplexing gains.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If non-linear multiple-antenna processing is applied between DFT and IFFT, then diversity gain and multiplexing gain are improved, but PAPR characteristics are degraded

Engineering Contradiction:
Improvediversity gainVSAvoidPAPR
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary action by performing the multiple-antenna processing operation before the DFT processing, rather than after. This reordering ensures that the non-linear processing occurs on the time-domain signal before transformation to frequency domain, thereby maintaining PAPR characteristics while still achieving diversity and multiplexing gains through the non-linear operation.

Inventive Principle:
Principle #10Preliminary action

2Object-affected harmful factors

If linear multiple-antenna processing is applied to maintain PAPR, then PAPR characteristics are preserved, but diversity gain and multiplexing gain are reduced

Engineering Contradiction:
ImprovePAPRVSAvoiddiversity gain
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

By moving the multiple-antenna processing to occur before DFT (preliminary action), the system achieves non-linear processing effects that improve diversity and multiplexing gains, while the subsequent DFT and IFFT operations maintain the PAPR characteristics. This resolves the contradiction by achieving both goals through reordering operations.

Inventive Principle:
Principle #10Preliminary action

3Adaptability or versatility

If multiple-antenna processing is added between DFT and IFFT, then system functionality is enhanced, but data linearity is destroyed

Engineering Contradiction:
Improvesystem functionalityVSAvoiddata linearity
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The patent applies preliminary action by performing multiple-antenna processing before DFT transformation. This ensures that the non-linear processing occurs in the time domain, and the subsequent DFT and IFFT operations restore the signal to frequency domain with preserved linearity characteristics, thus maintaining both enhanced functionality and data linearity.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2375579B1Multiple-antenna signal processing system and method
Publication Date: 2015.10.07 ZTE CORP
  • EP2375579B1 patent drawingFigure 1~3
  • EP2375579B1 patent drawingFigure 4~5
  • EP2375579B1 patent drawingFigure 6~7

AI summary

A multiple-antenna signal processing system and method are provided. The system includes: a Discrete Fourier Transform DFT processing unit, a multiple-antenna processing and resource element mapping unit, and an Inverse Fast Fourier Transform IFFT processing unit, the system also includes a pre-mapping processing unit, which is configured to perform a mapping on input data stream(s) based on a processing mode of a current multiple-antenna processing, so as to realize the pre-mapping processing, and outputs the pre-mapped data stream(s) to the DFT processing unit.