Transceiver Architecture Maintaining Legacy Timing via Sampling Rate Adjustment

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Solution Overview

Problem

Existing Narrowband (NB) Long Term Evolution (LTE) solutions face challenges with high sampling rates that are expensive and power-consuming, making them unsuitable for low-cost Machine Type Communication (MTC) applications, which require reduced device processing capability and extended battery life.

Innovation Solution

The proposed transceiver architecture reduces sampling rates and FFT processing complexity by upsampling and downsampling baseband signals while maintaining the legacy LTE time-domain structure, using a 240 kHz sampling rate and 16-point FFT/IFFT instead of the legacy 1.92 MHz rate and 128-point FFT/IFFT, thereby reducing device costs and power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If legacy LTE sampling rates (1.92 MHz) are used to maintain timing structure, then compatibility with legacy LTE systems is ensured, but device cost and power consumption increase

Engineering Contradiction:
Improvecompatibility with legacy LTE systemsVSAvoidpower consumption
Core Design Contradiction:
Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The patent changes the sampling rate parameter from the legacy 1.92 MHz to a reduced rate while maintaining the essential timing structure through careful design of the cyclic prefix and symbol boundaries, thereby reducing power consumption while preserving compatibility

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent extracts and maintains only the critical timing elements (symbol boundaries, cyclic prefix structure) that ensure legacy compatibility, while removing the requirement to process at the full legacy sampling rate, thus reducing power consumption

Inventive Principle:
Principle #2Taking out (Extraction)

2Adaptability or versatility

If legacy LTE sampling rates (1.92 MHz) are used to maintain timing structure, then compatibility with legacy LTE systems is ensured, but device complexity increases

Engineering Contradiction:
Improvecompatibility with legacy LTE systemsVSAvoidprocessing capability requirements
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent changes the sampling rate parameter and corresponding FFT size from 1.92 MHz/128-point to a reduced rate with smaller FFT, simplifying the processing capability requirements while maintaining timing compatibility through preserved symbol and cyclic prefix structures

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent extracts and maintains only the essential timing structure elements required for legacy compatibility, while removing the requirement for high-rate sampling and large FFT processing, thus reducing device complexity

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If higher sampling rates are used for NB LTE, then better signal processing performance is achieved, but battery life is reduced

Engineering Contradiction:
Improvesignal processing performanceVSAvoidbattery life
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The patent changes the sampling rate parameter to a reduced value that still provides adequate signal processing performance for narrowband applications, thereby extending battery life while maintaining acceptable reliability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies partial sampling action at reduced rates that are sufficient for narrowband signal processing needs, avoiding the excessive power consumption of full legacy rates while maintaining adequate performance

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP3326342B1Transceiver architecture that maintains legacy timing by inserting and removing cyclic prefix at legacy sampling rate
Publication Date: 2019.09.25 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3326342B1 patent drawingFigure 1
  • EP3326342B1 patent drawingFigure 2A~2B
  • EP3326342B1 patent drawingFigure 3A~3B

AI summary

Systems and methods relating to a transceiver architecture that maintains legacy timing by inserting and removing a cyclic prefix at a legacy sampling rate are disclosed. In some embodiments, a system for a receiver comprises an upsampling subsystem, a cyclic prefix removal unit, and a downsampling subsystem. The upsampling subsystem is operable to process a first baseband receive signal that is at a first sampling rate to generate an upsampled baseband receive signal at a second sampling rate that is greater than the first sampling rate. The cyclic prefix removal unit is operable to remove a cyclic prefix from the upsampled baseband receive signal to provide a second baseband receive signal at the second sampling rate. The downsampling subsystem is operable to process the second baseband receive signal to generate a downsampled baseband receive signal at the first sampling rate. In this manner, complexity and power consumption are reduced.