Satellite Bidirectional Link Using Spread Spectrum Return
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current microwave radio signal transmission systems for digital television lack an efficient and cost-effective solution for bidirectional communication, particularly for interactive services and machine-to-machine applications, as existing methods require additional equipment, high costs, and complex infrastructure.
Innovation Solution
A microwave radio signal transmission/reception installation using a unit capable of receiving and demodulating forward links, and modulating return links using a spread-spectrum protocol, with a coaxial cable connecting the outdoor unit to indoor boxes, allowing for efficient and inexpensive bidirectional communication by leveraging existing infrastructure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a two-directional satellite television broadcasting system uses separate Ku band and L band reflectors, then bidirectional communication capability is achieved, but device complexity and cost increase significantly
Solution Approach 1:
The patent applies a single reflector that handles both forward link (Ku band reception) and return link (L band transmission) functions. The reflector is designed with a feed horn that can receive Ku band signals and transmit L band signals, eliminating the need for separate Ku band and L band reflectors. This multi-functional approach reduces device complexity while maintaining bidirectional communication capability.
Solution Approach 2:
The patent merges the forward link and return link physical data routing paths into a single coaxial cable infrastructure. Instead of requiring separate cables for Ku band antenna to STB and STB to L band antenna, the invention combines both signal paths through one cable, reducing installation complexity and cost.
2Speed
If signal amplification is used to compensate for coaxial cable loss on the return link, then communication range is extended, but power loss and cost increase
Solution Approach 1:
The patent changes the frequency parameter by using L band (lower frequency) for the return link transmission instead of Ku band. Lower frequency signals experience less attenuation in coaxial cables, naturally compensating for cable loss without requiring additional amplification equipment. This parameter change reduces both power loss and system cost.
3Ease of manufacture
If existing terrestrial or satellite broadcasting infrastructure is used for return link, then additional equipment cost is reduced, but communication efficiency and suitability for small volume messages deteriorate
Solution Approach 1:
The patent introduces a hybrid architecture where a terrestrial wireless communication link (using L band and spread spectrum technology) serves as an intermediary for the return path. This intermediary system is specifically suited for small volume messages like votes and commands, combining the cost advantage of using existing infrastructure with the efficiency needed for interactive services.
Data Source
AI summary
A transmission/reception installation for microwave radio signals, including a unit for transmission/reception including a receiver for receiving the electric signals from the conversion of radio signals received via a terrestrial or satellite link, referred to as forward-link signals, a demodulator for demodulating the electric signals using a first modulation/demodulation protocol, a modulator for modulating electric signals using a second modulation/demodulation protocol that is different than the first protocol, the second protocol being a spread-spectrum protocol, the modulator modulating the signals demodulated by the demodulator, and a converter for converting the electric signals modulated using a spread-spectrum protocol into radio signals that can be transmitted via a satellite link. The installation also includes one or more boxes including a modulator for modulating the electric signals using the first modulation/demodulation protocol, and a coaxial cable connecting the unit for transmission/reception to the boxes.