MIMO FTN Transmission via Frequency Band Partitioning

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Solution Overview

Problem

In MIMO environments, existing techniques face challenges with spectral leakage due to pre-coding methods, leading to interference and reduced spectral efficiency, particularly in Faster-Than-Nyquist signaling where orthogonality is relaxed, necessitating complex detection algorithms.

Innovation Solution

The method involves forming multiple spatial data streams and partitioning the frequency band into sub-bands for FTN sampling, using precoding based on channel state information and singular value decomposition to allocate different gains to each stream, simplifying detection and reducing complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If pre-coding is used in MIMO systems to transmit multiple streams, then spatial diversity and reliability are improved, but spectral leakage and interference increase due to changes in signal spectrum

Engineering Contradiction:
Improvereliability of data transmissionVSAvoidspectral leakage and interference
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The frequency band is divided into multiple sub-bands, and each sub-band is allocated to a specific spatial stream. This segmentation prevents spectral leakage from affecting other streams, as each stream operates in its designated frequency portion. The channel matrix is also segmented into sub-band matrices for independent processing.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different gain values are applied to different spatial streams based on their respective channel conditions in specific sub-bands. The precoding matrix is designed to provide localized optimization for each stream-sub-band combination, improving reliability without causing widespread spectral leakage.

Inventive Principle:
Principle #3Local quality

2Productivity

If Faster-Than-Nyquist sampling is used to increase transmission rate, then spectral efficiency is improved, but detection complexity increases due to loss of orthogonality

Engineering Contradiction:
Improvetransmission rate and spectral efficiencyVSAvoiddetection algorithm complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The system divides the frequency band into sub-bands and applies FTN sampling within each sub-band rather than across the entire band. This segmentation allows the use of simpler detection algorithms for each sub-band while maintaining the high spectral efficiency benefits of FTN sampling.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system changes the sampling rate parameter to exceed the Nyquist rate for FTN transmission, achieving higher spectral efficiency. However, by combining this with frequency band partitioning, the detection complexity is managed through localized processing in each sub-band.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If uncoded SEFDM system is used to achieve bandwidth savings, then spectral efficiency is improved, but detection complexity increases requiring complex detectors such as maximum likelihood

Engineering Contradiction:
Improvethroughput and bandwidth utilizationVSAvoiddetection architecture complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The frequency band is segmented into sub-bands with each sub-band processed independently. This segmentation enables the use of simpler detection methods for each sub-band while achieving the overall spectral efficiency of SEFDM systems.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Precoding is applied locally to each spatial stream with specific gain values tailored to channel conditions in corresponding sub-bands. This localized precoding simplifies detection compared to uncoded SEFDM while maintaining bandwidth efficiency.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3284184B1Multi-stream faster-than-nyquist transmission using bandwidth partitioning
Publication Date: 2019.09.11 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3284184B1 patent drawingFigure 1a~1b
  • EP3284184B1 patent drawingFigure 2
  • EP3284184B1 patent drawingFigure 3

AI summary

The present disclosure generally relates to the field of Faster-Than-Nyquist Signaling. More specifically, the present disclosure relates to a technique of supporting Faster- Than-Nyquist transmission of data in a Multiple Input Multiple Output environment. A method embodiment comprises: forming two or more spatial data streams from data to be transmitted in the MIMO environment; partitioning a frequency band available for transmission of the data in the MIMO environment over the two or more spatial data streams into two or more sub-bands; and processing each of the two or more spatial data streams using FTN sampling.