Interleaver Structure for Long Code Words in Slowly Varying Channels
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Solution Overview
Problem
Existing digital transmission technologies face challenges in efficiently handling channels with slowly changing properties, leading to high complexity and memory requirements in both transmitters and receivers, particularly in broadcasting applications where receivers need to be cost-effective and handle long code words.
Innovation Solution
The implementation of an interleaver structure that processes data in interleaving units rather than individual symbols, allowing for scalable and efficient transmission by rearranging the sequence of interleaving units while maintaining the order of symbols within each unit, thereby reducing the need for complex symbol-by-symbol processing and memory management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If symbol-by-symbol interleaving is used to handle slowly changing channel properties, then transmission reliability is improved, but receiver complexity and memory requirements increase significantly
Solution Approach 1:
The patent divides the code word into multiple interleaving units, where each unit contains a group of symbols rather than individual symbols. This segmentation reduces the granularity of interleaving operations from symbol-by-symbol to unit-by-unit, thereby reducing receiver complexity and memory requirements while still providing adequate protection against slowly varying channel conditions.
2Reliability
If long interleavers are used to handle slowly fading channels, then transmission reliability is improved, but memory requirements and processing complexity increase
Solution Approach 1:
The code word is divided into multiple interleaving units, each containing multiple symbols. This segmentation allows the interleaver to operate on coarser granularity, reducing the total number of interleaving operations and corresponding memory requirements while still achieving adequate diversity for slowly fading channels.
3Reliability
If conventional interleaving structures are used for long code words, then error correction capability is improved, but processing time and end-to-end delay increase
Solution Approach 1:
By dividing the code word into multiple interleaving units that can be processed independently, the patent enables parallel processing and reduces the sequential processing time. This segmentation maintains error correction capability while reducing end-to-end delay through more efficient processing architecture.
Solution Approach 2:
The interleaving units are structured and prepared in advance with predetermined patterns, allowing the receiver to efficiently decode without requiring complex real-time processing. This preliminary structuring reduces processing time while maintaining error correction performance.
4Productivity
If high-rate FEC codes are used to reduce transmission time, then productivity is improved, but error correction capability deteriorates
Solution Approach 1:
The patent uses segmentation into interleving units that can be independently decoded, allowing the system to use higher code rates for faster transmission while maintaining adequate error correction through the diversity provided by the interleaving structure across multiple units.
Data Source
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AI summary
A transmitter for generating a transmit signal comprises a redundancy-adding encoder (22), an interleaver device for processing a sequence of codewords, wherein the interleaver device has a block interleaver (18) and a downstream interleaving device (10), and a modulator (26) for modulating a data stream output by the interleaving device (10) of the interleaver device onto a transmission channel.