CLIER Amplifier Signal Splitting for Radio-over-Fiber Noise Reduction
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Solution Overview
Problem
Current radio-over-fiber technologies face challenges with noise, non-linearities, and high costs due to the need for sophisticated optical modulation techniques and signal conditioning, particularly in transmitting analogue radio frequency signals, which results in deteriorated transmission quality.
Innovation Solution
Implementing a CLIER amplifier architecture divided into two remote parts connected by an optical connection, where data signals are represented as envelope and phase components, with the envelope signal filtered and phase signals split into constant amplitude components for optical transmission and recombination at the receiving end, using electro-optical and opto-electrical converters to achieve amplification and signal reconstruction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If analogue radio frequency signals are transmitted using conventional radio-over-fiber technologies, then signal transmission is achieved, but transmission quality deteriorates due to noise, non-linearities, and chromatic dispersion
Solution Approach 1:
The patent replaces the conventional approach of transmitting analogue radio frequency signals directly through optical fibers with a method that converts these signals to digital domain, transmits digitally modulated optical signals, and then converts back to analogue. This substitution of the signal representation domain (from direct analogue optical transmission to digital-electrical-optical-analogue conversion) eliminates the harmful effects of noise, non-linearities, and chromatic dispersion that plague analogue transmission systems.
Solution Approach 2:
The patent fundamentally changes the signal parameters by converting analogue radio frequency signals into digital baseband signals for transmission. This parameter transformation allows the use of digital modulation schemes that are inherently more robust against transmission impairments. The digital domain processing enables precise control of signal characteristics and immunity to the analog degradation mechanisms mentioned in the contradiction.
2Reliability
If highly sophisticated optical modulation techniques and signal conditioning are used to improve transmission quality, then transmission quality improves, but hardware complexity and cost increase
Solution Approach 1:
The patent replaces complex analogue optical modulation techniques with digital signal processing approaches. By converting signals to the digital domain before transmission and using standard digital modulation schemes, the system achieves high transmission quality without requiring sophisticated analogue optical modulators and complex signal conditioning circuits. The digital domain provides simpler, more standardized modulation techniques.
Solution Approach 2:
The patent introduces digital signal processing as an intermediary between the radio frequency domain and the optical transmission domain. This digital intermediary layer simplifies the overall system by providing a well-defined interface where complex signal conditioning can be performed using standard digital processing techniques rather than requiring complex optical modulation hardware.
3Ease of manufacture
If intensity modulation and direct detection are used for optical transmission, then the system is straightforward and simple, but costly modulators and modulator drivers are required to meet analogue radio frequency transmission requirements
Solution Approach 1:
The patent substitutes the direct analogue optical modulation approach with a digital conversion approach. Instead of using complex modulators and modulator drivers to directly modulate optical carriers with analogue radio frequency signals, the system converts signals to digital baseband, applies digital modulation, and then uses simpler optical modulation techniques for transmission. This eliminates the need for costly analogue modulator hardware.
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
This approach reduces costs and hardware effort, enhances transmission quality, and allows for easy scaling in beamforming and MIMO applications by utilizing digital optical signals, which are more fault-tolerant against interference.
Implementation Method 1
at least one of the group of the two phase modulated signal components of constant amplitude and the filtered envelope signal component is converted from an electrical signal into an optical signal in at least one electro-optical converter located in the transmitting device
Implementation Method 2
the at least one of the group of the two phase modulated signal components of constant amplitude and the filtered envelope signal component is converted from an optical signal into an electrical signal in at least one opto-electrical converter located in said at least one receiving device
Data Source
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AI summary
The invention concerns a method for transmission of a data signal from a transmitting device (BS) to a receiving device (RAH1) using an amplifier (AMP) for signal amplification, wherein signal components of the data signal are transmitted over at least one optical connection from a first part of the amplifier located in the transmitting device (BS) to a second part of the amplifier (AMP) located in the receiving device (RAH1), an amplifier, a transmitting device and a receiving device therefor.