Optical Transponder Subcarrier Multiplexing for Spectrum Efficiency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing optical communication systems face inefficiencies in bandwidth use and increased costs due to the implementation of large-capacity transponders in areas with lower communication requirements, leading to suboptimal use of transponder capabilities and spectrum efficiency.
Innovation Solution
An optical transmission device is designed with nodes allocated different carrier frequencies, using a combination of subcarriers and optical splitters/couplers to efficiently transmit and receive signals between adjacent nodes, allowing for communication with two nodes using a single transponder, thereby reducing the number of transponders needed and enhancing spectrum use efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If large-capacity transponders are implemented in areas with lower communication requirements, then communication capacity is sufficient, but bandwidth use efficiency decreases and costs increase
Solution Approach 1:
The system dynamically allocates transponder resources by enabling a single transponder to serve multiple nodes through subcarrier multiplexing. The transponder can adaptively adjust its operation mode between serving one node at full capacity or multiple nodes with shared capacity, allowing the network to match communication capacity to actual demand in different areas without wasting bandwidth resources.
Solution Approach 2:
The transponder is designed with multi-functionality to communicate with multiple different nodes using different subcarriers. By implementing subcarrier division, a single transponder can function as multiple communication channels, serving both high-capacity city areas and lower-capacity rural areas with the same hardware resource, thereby improving bandwidth use efficiency while maintaining adaptability to various communication requirements.
2Adaptability or versatility
If large-capacity transponders are implemented in areas with lower communication requirements, then communication capacity is sufficient, but the cost of establishing the optical network increases
Solution Approach 1:
The invention merges the functions of multiple transponders into a single transponder by implementing subcarrier multiplexing. Instead of deploying separate transponders for each node connection, the system combines multiple communication channels within one transponder using different subcarriers. This reduces the total number of transponders required in the network, lowering equipment costs and simplifying network infrastructure while maintaining the ability to provide sufficient communication capacity across different area types.
3Productivity
If a single transponder communicates with multiple nodes using different subcarriers, then bandwidth use efficiency improves, but signal separation and reception complexity increases
Solution Approach 1:
The system segments the communication signal into multiple subcarriers, each carrying independent data streams to different nodes. By dividing the broadband signal into narrower subcarrier frequency bands, the receiver can separately process and demodulate each subcarrier using standard coherent reception techniques. This segmentation approach enables efficient bandwidth utilization while managing signal processing complexity through frequency-domain separation rather than requiring complex time-domain multiplexing.
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 optimizes transponder usage and reduces costs by allowing full utilization of transponder capabilities, especially in areas with lower communication demands, while maintaining high frequency use efficiency.
Implementation Method 1
a first light source configured to generate local oscillation light of a first carrier frequency that is allocated to the first node
Implementation Method 2
a transmitter configured to generate, by using the local oscillation light, a first subcarrier optical signal with a first subcarrier established on a low-frequency side of the first carrier frequency and a second subcarrier optical signal with a second subcarrier established on a high-frequency side of the first carrier frequency
Implementation Method 3
an optical splitter configured to split an optical signal including the first subcarrier optical signal and the second subcarrier optical signal to generate a first optical signal to be transmitted to a first adjacent node and a second optical signal to be transmitted to a second adjacent node
Implementation Method 4
an optical coupler configured to combine an optical signal received from the first adjacent node and an optical signal received from the second adjacent node
Implementation Method 5
a receiver configured to recover, by using the local oscillation light, a first reception signal carried by the first subcarrier and a second reception signal carried by the second subcarrier from an output optical signal of the optical coupler
Data Source
AI summary
Optical transmission device is provided in one of a plurality of nodes in an optical network. Different carrier frequencies are respectively allocated to the plurality of nodes. The optical transmission device includes: transmitter, splitter and receiver. The transmitter generates a first subcarrier optical signal with a first subcarrier established on a low-frequency side of a first carrier frequency and a second subcarrier optical signal with a second subcarrier established on a high-frequency side of the first carrier frequency. The splitter splits an optical signal including the first subcarrier optical signal and the second subcarrier optical signal. The output of the splitter is guided to first and second adjacent nodes. The receiver recovers data carried by the first subcarrier and data carried by the second subcarrier from received optical signal. A difference between carrier frequencies of adjacent nodes corresponds to a bandwidth of the subcarrier.