Multiband Transmission System Frequency Separation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing multiband transmission systems face issues with signal intermodulation when combining wireless communication and digital network signals, leading to degraded signal quality due to overlapping frequency bands, particularly in frequency division multiplexing systems.

Innovation Solution

A multiband transmission system utilizing a master unit and remote unit with a reference frequency generator and receiver, where the reference frequency is used to separate and combine signals from wireless and digital networks, avoiding intermodulation by converting overlapping frequency bands into free intermediate frequency bands, and using this reference frequency for clocking and modulation/demodulation processes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If frequency division multiplexing is used to transmit signals from wireless communication networks and digital networks simultaneously, then the system can handle multiple frequency bands and signal types, but unwanted intermodulation occurs between frequency bands degrading signal quality

Engineering Contradiction:
Improveability to handle multiple frequency bands and signal typesVSAvoidintermodulation between frequency bands
Core Design Contradiction:
Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The patent introduces an intermediary frequency conversion stage between the wireless communication signals and digital network signals. The master unit converts wireless signals to intermediate frequencies and the remote unit converts them back, creating a frequency buffer that prevents direct intermodulation between different signal types while still allowing simultaneous transmission over the same physical medium.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the frequency parameter of wireless communication signals by converting them to intermediate frequencies at the master unit before transmission over the digital network. This parameter transformation allows different signal types to coexist without intermodulation, as the intermediate frequency conversion isolates their frequency spectra.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If frequency division multiplexing is used to separate signal directions, then bidirectional communication is enabled, but clean separation of frequency bands on the receiver side becomes difficult

Engineering Contradiction:
Improvebidirectional communication capabilityVSAvoidfrequency band separation cleanliness
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The intermediary frequency conversion at both master and remote units acts as a mediator that preserves frequency band separation. By converting signals to intermediate frequencies for transmission and back at the destination, the system maintains clean frequency separation even while enabling bidirectional communication through the same physical medium.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The master unit performs preliminary frequency conversion of wireless signals to intermediate frequencies before they are transmitted over the digital network. This preliminary action ensures that when signals are received and converted back at the remote unit, the frequency bands remain cleanly separated, avoiding interference between different signal types.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2499878B1Master unit, remote unit and multiband transmission system
Publication Date: 2021.04.28 ANDREW WIRELESS SYSTEMS GMBH(DE)
  • EP2499878B1 patent drawingFigure 1
  • EP2499878B1 patent drawingFigure 2

AI summary

The invention relates to a master unit (2, 2') and a remote unit (3) for a multiband transmission system (1) for distributing and combining signals of at least one wireless communication network and at least one digital network. According to the invention, a reference frequency generator (12) is arranged in the master unit (2), said reference frequency generator being designed to clock a master modem (5, 5', 6, 6') for converting the signals of the at least one digital network. The reference frequency signal emitted by the reference frequency generator (12) is transmitted to the remote unit (3) in the downlink direction (DL). There, the reference frequency signal is restored by means of a reference frequency receiver (40) and used for clocking a remote modem (38, 38', 39, 39') that is located there for demodulation.