Quad Band Relay Link Reliability Against Multipath Fading
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The Common Data Link (CDL) system experiences significant performance and reliability losses due to multipath interference and fading, particularly in low Angle of Arrival (AoA) operating conditions, which existing technologies have not effectively addressed.
Innovation Solution
The Quad band Relay (QbR) system employs frequency diversity and data redundancy by creating and transmitting multiple waveforms at different center frequencies, allowing for redundant data streams to mitigate multipath interference and fading, while maintaining legacy compatibility through an efficient hardware and digital signal processing enhancement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single frequency waveform is transmitted in the CDL system, then the system maintains simplicity and legacy compatibility, but the system suffers significant performance losses due to multipath interference and fading
Solution Approach 1:
The patent segments the single data stream into multiple parallel waveforms transmitted at different center frequencies (f0, f1, f2, f3). Each waveform carries a portion of the encoded data stream, allowing the receiver to combine them for improved reliability. This segmentation enables frequency diversity without requiring complete system redesign, maintaining legacy compatibility while improving performance.
Solution Approach 2:
The patent changes the frequency parameter by transmitting the same encoded data stream at multiple different center frequencies simultaneously. This frequency diversity approach allows the system to overcome multipath interference and fading effects that affect single-frequency transmissions, as different frequency components experience different channel conditions.
2Reliability
If multiple waveforms at different frequencies are transmitted to overcome multipath interference, then frequency diversity is achieved, but the device complexity and processing requirements increase
Solution Approach 1:
The patent designs the communication system with multi-functionality to handle both legacy single-frequency transmissions and new multi-frequency diverse transmissions. The receiver can process either single or multiple waveforms depending on the transmission mode, making the system universal and adaptable without requiring completely separate hardware for different operational modes.
Solution Approach 2:
The patent creates multiple copies of the encoded data stream, each modulated onto a different frequency carrier (f0, f1, f2, f3). These copies are transmitted simultaneously through the same channel, and the receiver combines them to achieve diversity gain. This copying approach simplifies the transmitter design while providing robustness against frequency-specific interference.
3Reliability
If redundant data streams are transmitted at different center frequencies, then link-loss due to multipath is reduced, but the quantity of transmitted data and processing load increases
Solution Approach 1:
The patent implements partial redundancy by transmitting encoded versions of the data stream at multiple frequencies rather than complete duplicate transmissions. The encoding process (such as spreading codes or modulation schemes) ensures that partial reception of multiple frequency components is sufficient to reconstruct the original data, reducing the total data volume compared to full redundancy while maintaining reliability.
Data Source
AI summary
A method of increasing reliability of a wireless radio includes: creating a first waveform at a first center frequency of an encoded data stream using a first wireless radio; creating a second waveform at a second center frequency of the encoded data stream using the first wireless radio; combining the first waveform and the second waveform into a composite waveform with redundant data streams at different center frequencies using the first wireless radio; wirelessly transmitting the composite waveform using the first wireless radio; wirelessly receiving the composite waveform; filtering the received composite waveform using a first filter band; digitizing the received composite waveform using the second wireless radio; demodulating the digitized composite waveform into a first data stream and a second data stream with the second wireless radio; and creating a third data stream representative of the encoded data stream.