PL Header Convolutional Coding for Multi-Carrier DVB-S2 Links
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Solution Overview
Problem
Current DVB-S2 PLS coding schemes lack the capability to support multi-carrier multiplexing in wideband transponders, limiting their ability to efficiently process high-capacity satellite systems and requiring additional layers of coding and decoding, which increases complexity and cost.
Innovation Solution
Implementing a convolutional code, such as a (16,154) convolutional code, for DVB-S2 PLS coding to enhance the coding performance and support multi-carrier multiplexing by generating an extended PLS Code that includes stream identification and increased MODCOD capabilities, allowing for robust modulation and coding schemes like QPSK rate 1/4.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the current DVB-S2 PLS coding scheme is used, then the implementation is simple and cost-effective, but it lacks the capability to support multi-carrier multiplexing in wideband transponders
Solution Approach 1:
The patent changes the fundamental parameters of the PLS coding scheme by transitioning from Reed-Muller codes to convolutional codes with specific generator polynomials. This parameter change enables the code to support multi-carrier multiplexing while maintaining implementation feasibility through well-established convolutional decoding techniques.
Solution Approach 2:
The patent introduces dynamic elements to the PLS coding scheme by enabling adaptive coding rates and flexible packet structures that can accommodate varying multiplexing requirements. The convolutional code allows for dynamic adjustment of coding parameters to optimize performance for different multi-carrier configurations.
2Adaptability or versatility
If additional layers of coding and decoding are added to support multiplexing, then the capability to handle multiplexed streams is improved, but the complexity and cost of decoder ASICs increases
Solution Approach 1:
The patent merges the PLS coding function with the data coding function by using the same convolutional code for both purposes. This consolidation eliminates the need for separate coding/decoding layers, reducing ASIC complexity while maintaining full multiplexing support capability.
Solution Approach 2:
The convolutional code is designed to serve multiple functions simultaneously: it provides error correction for PLS headers, supports multi-carrier multiplexing identification, and enables flexible coding rates. This multi-functionality reduces the need for specialized additional coding layers.
3Productivity
If the outroute bandwidth is increased to greater than 200 Msps for next generation systems, then the transmission capacity is improved, but the processing speed requirement for decoder ASICs increases
Solution Approach 1:
The patent segments the high-speed outroute into multiple lower-speed logical streams through virtual channel mapping. The convolutional PLS code enables identification of packets belonging to different virtual channels, allowing the decoder to process data at lower effective speeds while maintaining support for high-capacity outroutes exceeding 200 Msps.
Data Source
Figure 1A~1B
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AI summary
An approach for encoding a physical layer (PL) header of a PL data frame is provided. The PL header comprises sixteen information bits ui, (i = 0,1, 2, ... ,15), and the encoding is based on a convolutional code, whereby, for each information bit, five associated parity bits pi,k, (k = 0, 1, 2, 3, 4) are generated, resulting in 80 codebits. The resulting 80 codebits are punctured to form a (16,77) codeword (c0, c1, c2, ..., c76). The codebits of the (16,77) codeword are repeated to generate a (16,154) physical layer signaling codeword (c0, c0, c1, c1, c2, c2, ... , c76, c76) for transmission of the PL data frame over a channel of a communications network. Further, for each information bit, each of the associated five parity bits is generated based on a parity bit generator, as follows: pi,k = (ui * gk,0) ⊕ (S0 * gk,1)⊕(S1 * gk,2)⊕(S2 * gk,3)⊕(S3 * gk,4)⊕, where S0 = ui-1, S1 = ui-2, S2 = ui-3, S3 = ui-4 , and wherein generator polynomials for gk = (gk,0,gk,1,gk,2,gk,3,gk,4,), are as follows: g0 = (1,0,1,0,1); g1 = (1,0,1,1,1); g2 = (1,1,0,1,1); g3 = (1,1,1,1,1); g4 = (1,1,0,0,1).