Front Haul Data Compression Using PCA for 5G Radio Units

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Solution Overview

Problem

5G wireless communication systems face challenges in achieving high bandwidth utilization while maintaining low computational complexity at the radio unit due to the heavy burden on the front haul interface, especially when air interface load is low, and existing solutions do not adequately address bandwidth utilization even under high load conditions.

Innovation Solution

The method involves compressing time domain data using Principal Component Analysis (PCA) at the digital unit and transmitting the compressed data along with a compression parameter over the front haul interface, allowing for decompression at the radio unit, thereby reducing computational complexity at the radio unit and enhancing bandwidth utilization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If frequency domain signals are transformed into time domain signals and transmitted over the front haul interface, then bandwidth utilization is improved, but computational complexity at the radio unit increases

Engineering Contradiction:
Improvebandwidth utilizationVSAvoidcomputational complexity at radio unit
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent extracts the FFT/IFFT computational functions from the radio unit and relocates them to the digital unit. This separation allows the radio unit to only handle simple time-domain signal transmission over the front haul interface, while the computationally intensive frequency-domain transformations are performed remotely at the digital unit, thus reducing radio unit complexity while maintaining bandwidth utilization benefits

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a compression mechanism as an intermediary between the digital unit and radio unit. The compressed time-domain signals are transmitted over the front haul interface, and decompression is performed at the radio unit. This compression intermediary enables efficient bandwidth utilization while the computational burden is managed through the distributed architecture between digital and radio units

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If FFT and IFFT functions are implemented at the radio unit, then data transmission can be performed, but computational complexity and processing burden increase

Engineering Contradiction:
Improvedata transmission capabilityVSAvoidcomputational complexity at radio unit
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent extracts the FFT/IFFT computational functions from the radio unit and relocates them to the digital unit. This separation allows the radio unit to only handle simple time-domain signal transmission over the front haul interface, while the computationally intensive frequency-domain transformations are performed remotely at the digital unit, thus reducing radio unit complexity while maintaining data transmission capability

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent segments the signal processing functions into two distinct locations: the digital unit handles frequency-domain operations (FFT/IFFT), and the radio unit handles time-domain transmission. This functional segmentation distributes computational tasks appropriately, reducing the processing burden on the radio unit while maintaining overall system productivity

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3844919B1Method and network device for data transmission over front haul interface
Publication Date: 2023.06.14 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3844919B1 patent drawingFigure 1
  • EP3844919B1 patent drawingFigure 2~3
  • EP3844919B1 patent drawing

AI summary

The present disclosure provides a method (200) in a network device for data transmission over a front haul interface between a first unit and a second unit. The method (200) includes: compressing (210), at the first unit, time domain data in frequency domain and/or spatial domain; transmitting (220) the compressed time domain data along with an associated compression parameter over the front haul interface from the first unit to the second unit; and decompressing (230), at the second unit, the compressed time domain data based on the compression parameter.