Multi-Subcarrier Radio Transmission Without Mechanical Filters
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing point-to-point radio transmission systems are limited by bandwidth constraints, require complex and costly mechanical filters, and are difficult to reconfigure, leading to significant power loss and manufacturing challenges, especially at frequencies above 13 GHz.
Innovation Solution
A multi-channel transmission system using digital signal processing techniques, including inverse spectral transforms and polyphase filters, allows for dynamic configuration of transmission channels and subcarriers, eliminating the need for selective mechanical filters and reducing power loss by using microstrip technology for bandpass filters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional mechanical filters are used to achieve high frequency selectivity, then the filtering performance is improved, but the device complexity and manufacturing cost increase significantly
Solution Approach 1:
The patent replaces mechanical filters with digital signal processing techniques. Specifically, it uses Fast Fourier Transform (FFT) to convert time-domain signals to frequency-domain signals, applies digital filtering in the frequency domain, and then uses Inverse Fast Fourier Transform (IFFT) to convert back to time domain. This substitution eliminates the need for complex mechanical filters while achieving the required frequency selectivity.
Solution Approach 2:
The patent changes the operating parameters by using digital signal processing instead of analog filtering. The frequency selectivity is achieved through digital algorithms rather than physical filter characteristics, allowing for flexible and reconfigurable filtering without changing physical components.
2Productivity
If multiple single-channel transmission chains are coupled to increase transmission rate, then the data rate is improved, but the power loss increases due to multiple circulators and filters
Solution Approach 1:
The patent merges multiple single-channel transmission chains into a single multi-channel transmission chain. By using digital signal processing to handle multiple channels simultaneously in the frequency domain, the system achieves the same data rate as multiple separate chains but with significantly reduced power loss, as only one set of circulators and filters is needed.
Solution Approach 2:
The patent creates a universal transmission system that can handle multiple channels through a single transmission path. The digital signal processing architecture allows the same hardware to transmit multiple channels simultaneously, making the system multi-functional and reducing the need for duplicate components.
3Measurement precision
If cavity filters are used to achieve required rejection levels, then the filtering performance is improved, but the manufacturing cost and complexity increase
Solution Approach 1:
The patent replaces expensive cavity filters with digital signal processing. The rejection level previously achieved by physical cavity filters is now achieved through digital algorithms in the frequency domain, dramatically reducing manufacturing costs and complexity.
4Productivity
If the bandwidth of transmission channels is increased, then the data rate is improved, but the system complexity increases due to regulatory constraints and channel reconfiguration
Solution Approach 1:
The patent implements a dynamic channel configuration system where the number and bandwidth of channels can be modified through software rather than hardware changes. The digital signal processing architecture allows flexible reconfiguration of transmission parameters, enabling the system to adapt to different bandwidth requirements without increasing physical complexity.
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 system achieves efficient multi-channel transmission with reduced power loss, lower manufacturing costs, and flexibility in channel configuration, enabling operation in higher frequency bands up to 42 GHz without the complexity of traditional systems.
Implementation Method 1
point-to-point radio wave transmissions used particularly in transport networks forming the infrastructure of mobile networks, or in certain private radio networks. Typically, these transmissions are carried out in frequency bands between 6 and 42 GHz
Data Source
Figure 1~4
Figure 5~8
Figure 9~11
AI summary
The invention relates to a data transmission method, comprising the steps of: generating, from a data flow to be transmitted (Dxi), a plurality of flows of digital frequency-domain samples (Xi,j), each flow of digital samples modulating a respective subcarrier defining a respective subcarrier channel (CPj), converting the flows of frequency-domain samples into flows of time-domain samples (xi,j) through an inverse spectral transform (IDFT), combining the flows of time-domain samples into a composite flow (xi), translating in frequency the composite flow using a digital oscillator (NO1) to an intermediate frequency greater than 1 GHz, converting the translated composite flow into an analogue signal (x(t)), translating in frequency the analogue signal to a transmission frequency greater than 2 GHz, using an analogue oscillator (LO1) at a translation frequency (RF), filtering the analogue signal in order to attenuate the translation frequency, and emitting the filtered signal using an antenna (AT).