Transceiver Extended Frames for Low SNR Satellite Links
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing satellite communication systems face challenges in operating under extremely low Signal to Noise Ratio (SNR) conditions, such as -30dB, which affects data transmission rates and requires smaller, more power-efficient terminals with reduced antenna size, impacting link budget and spectral resource utilization.
Innovation Solution
A transceiver is designed to transmit and receive extended communication frames, comprising multiple repetitions of basic frames with the same payload, allowing for signal combination and error correction, along with code shortening and spreading, to enhance SNR and support communication under low SNR conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If smaller antenna and electronic equipment size are used to reduce terminal footprint, then equipment size and power requirements are reduced, but link budget deteriorates and communication reliability under low SNR conditions worsens
Solution Approach 1:
The transmission is divided into multiple extended frames, each containing multiple basic frames with the same payload. This segmentation allows the receiver to combine multiple transmissions to improve SNR, compensating for the smaller antenna's reduced signal collection capability.
Solution Approach 2:
Multiple received signals from repeated transmissions are combined at the receiver using signal combination techniques. This merging process accumulates signal energy while averaging out noise, effectively improving the SNR for small terminals with limited signal collection capability.
2Reliability
If data transmission rate is reduced to enable operation under extremely low SNR conditions, then communication becomes possible at -30dB SNR, but productivity and spectral efficiency deteriorate
Solution Approach 1:
The same payload is transmitted periodically across multiple extended frames at reduced data rates. This periodic repetition allows the receiver to accumulate sufficient signal energy over time to achieve reliable decoding at extremely low SNR conditions like -30dB.
Solution Approach 2:
The system changes the transmission parameter from high data rate to low data rate with repeated frames. By transmitting the same information multiple times at lower rates, the effective SNR is improved through signal combination, enabling communication at previously impossible SNR levels.
3Reliability
If extended frames with multiple basic frames are transmitted to improve SNR through signal combination, then communication under extremely low SNR is enabled, but device complexity and transmission time increase
Solution Approach 1:
The transceiver is designed to handle both transmission of extended frames and reception with signal combination capabilities. This multi-functional design consolidates the complexity into a single device that can operate bidirectionally, managing both the increased transmission structure and the combination processing.
Solution Approach 2:
The same payload is copied across multiple basic frames within extended frames. This copying approach simplifies the transmission structure by repeating identical content, making it easier to implement signal combination at the receiver without requiring complex error correction or retransmission protocols.
4Reliability
If code shortening and spreading are applied to basic frames to enhance SNR, then communication under low SNR conditions is improved, but device complexity and processing requirements increase
Solution Approach 1:
Traditional error correction mechanisms are replaced with code-based shortening and spreading techniques. These coding methods provide SNR enhancement through mathematical transformations rather than mechanical signal processing, reducing hardware complexity while maintaining processing effectiveness.
Data Source
Figure 1
Figure 2
AI summary
A method and a device are provided for use at one or more links of a communication network along which communications are exchanged under extremely low SNR conditions. The method comprises a step of transmitting an extended communication frame, which comprises a plurality of basic frames, wherein each of the plurality of basic frames included in the extended frame, comprises the same payload as all other basic frames included in the plurality of basic frames.