Frequency Hopping for LTE Uplink Power Distribution

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Solution Overview

Problem

The existing frequency mapping methods for LTE UL physical channels result in low flexibility of UL frequency resource allocation, leading to changes in instantaneous power distribution characteristics of transmission signals, causing distortion and reducing data throughput due to non-linearity of power amplifiers.

Innovation Solution

A radio communication apparatus and method that cyclically frequency shifts signals of multiple channels within an IDFT or IFFT bandwidth, maintaining a predetermined frequency interval to suppress changes in instantaneous power distribution characteristics and improve frequency utilization efficiency and throughput.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If frequency division multiplexing is used to simultaneously transmit PUSCH and PUCCH, then frequency utilization efficiency is improved, but instantaneous power distribution characteristics change between slots causing distortion

Engineering Contradiction:
Improvefrequency utilization efficiencyVSAvoidtransmission quality consistency
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies parameter changes by introducing a frequency shift amount parameter that is specifically configured for the second slot to compensate for power distribution changes. The frequency shift amount is determined based on the frequency resources allocated in the first and second slots, and this parameter is used to adjust the frequency allocation in the second slot so that the instantaneous power distribution characteristics remain consistent across both slots, thereby maintaining transmission quality while enabling frequency division multiplexing.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If inter-slot frequency hopping is applied to PUSCH and PUCCH, then frequency diversity is improved, but flexibility of UL frequency resource allocation is reduced

Engineering Contradiction:
Improvefrequency diversityVSAvoidflexibility of UL frequency resource allocation
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent applies dynamics by making the frequency allocation flexible through the introduction of a frequency shift amount that can be dynamically configured. Instead of fixed frequency hopping patterns, the system allows dynamic adjustment of frequency resources in the second slot based on the first slot's allocation and the calculated frequency shift amount. This dynamic approach maintains frequency diversity benefits while significantly improving the flexibility of uplink frequency resource allocation.

Inventive Principle:
Principle #15Dynamics

3Device complexity

If PUSCH and PUCCH are multiplexed into one signal sequence with DFT spreading, then transmission format is simplified, but data throughput is reduced

Engineering Contradiction:
Improvetransmission formatVSAvoiddata throughput
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent applies segmentation by separating the transmission of PUSCH and PUCCH into distinct frequency resources within the same time slot. Instead of multiplexing both signals into a single sequence with DFT spreading, the system allocates different frequency resources for each channel type. This segmentation allows each channel to be transmitted independently with its own optimization, thereby improving data throughput while maintaining relatively simple transmission formats through frequency division multiplexing.

Inventive Principle:
Principle #1Segmentation

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution effectively suppresses changes in instantaneous power distribution characteristics, reduces distortion caused by power amplifier non-linearity, and maintains data throughput by limiting the influence of frequency division multiplexing on the time waveform to only phase components, ensuring consistent transmission quality across slots.

Implementation Method 1

an inverse Fourier transform section that applies inverse discrete Fourier transform (IDFT) or inverse fast Fourier transform (IFFT) to the signals arranged in the first channel and the second channel

Methodology Applied
Scientific EffectInverse discrete Fourier transform:

Data Source

PatentEP2437401B1Wireless communication apparatus and frequency hopping method
Publication Date: 2020.03.11 SUN PATENT TRUST
  • EP2437401B1 patent drawingFigure 1
  • EP2437401B1 patent drawingFigure 2
  • EP2437401B1 patent drawingFigure 3

AI summary

Disclosed are a wireless communication apparatus and frequency hopping method which minimize the change in the instantaneous power distribution characteristics of the time waveform of transmission signals when a plurality of channels are multiplexed by frequency division. At a terminal (200), a mapping unit (212) maps the PUCCH to frequency resources of a first slot, maps the PUSCH to frequency resources, among the frequency resources of the first slot, separated exactly by predetermined frequency spacing (B) from the frequency resources to which the PUCCH is mapped, and cyclically shifts the frequencies so as to map the PUCCH and PUSCH to frequency resources, within an IDFT or IFFT bandwidth, of a second slot while maintaining the predetermined frequency spacing (B), thereby allowing frequency hopping of the PUCCH and PUSCH between the first slot and the second slot.