Bit Interleaver Block Sizing for Square Error-Correction Matrices
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Solution Overview
Problem
Existing interleavers in mobile communication systems, such as those in 3GPP Evolved UTRAN, face challenges with high codeword size flexibility and fine granularity, leading to interleavers that are not close to the desirable square form, resulting in a significant difference between the number of columns and rows, which affects the transformation of burst errors into statistically independent errors.
Innovation Solution
The method calculates the number of required blocks for each codeword size to ensure individual interleavers have approximately equal rows and columns, achieving a square form, with two strategies to adjust the number of rows based on the number of bits, ensuring optimal interleaving performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a fixed number of columns and rows is used in interleavers (e.g., N=30, R=32), then the device complexity is reduced and ease of manufacture is improved, but the adaptability to different codeword sizes deteriorates and the interleaving performance worsens due to deviation from square form
Solution Approach 1:
The patent applies dynamics by making the number of rows R dynamic rather than fixed. The interleaver calculates R based on the actual codeword size L and number of blocks k using the formula R = ceil(L/(N*k)), allowing the interleaver dimensions to adapt dynamically to different transmission conditions and codeword sizes while maintaining the fixed column number N=30.
Solution Approach 2:
The patent changes the parameter R (number of rows) based on input conditions. By adjusting R according to the codeword size and number of blocks, the interleaver maintains optimal square form (N≈R) for different codebook sizes, thereby improving adaptability without significantly increasing implementation complexity.
2Adaptability or versatility
If the number of rows and columns in interleavers are not approximately equal, then the flexibility towards different codeword sizes is improved through fixed parameters, but the interleaving performance deteriorates as burst errors cannot be effectively transformed into statistically independent errors
Solution Approach 1:
The patent makes the interleaver dimensions dynamic by calculating R based on actual transmission needs. This dynamic adjustment ensures that the interleaver maintains approximately square form (N≈R) for different codeword sizes, which is essential for effectively transforming burst errors into statistically independent errors and maintaining high error correction performance.
Solution Approach 2:
The patent segments the codeword into multiple blocks and processes each block through an individual interleaver with dynamically adjusted dimensions. This segmentation approach, combined with dynamic sizing, allows the system to handle variable codeword sizes while maintaining optimal interleaving performance for each segment.
3Reliability
If individual interleavers are designed with N≈R for optimal performance, then the error transformation effectiveness is improved, but the device complexity increases due to the need to calculate and adjust the number of blocks and rows for each codeword size
Solution Approach 1:
The patent manages complexity by systematically changing parameters R and k based on the codeword size L. The calculation R = ceil(L/(N*k)) provides a straightforward method to determine optimal dimensions, balancing performance requirements with implementation complexity. This parameter adjustment approach ensures N≈R for optimal error transformation while maintaining manageable complexity through formula-based calculation.
Solution Approach 2:
The interleaver design enables self-configuration by automatically calculating the appropriate number of rows R and blocks k based on the input codeword size. This self-service mechanism eliminates the need for external configuration tables or complex control logic, reducing device complexity while maintaining optimal performance through automatic adaptation to different codeword sizes.
Data Source
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AI summary
The invention concerns a method for interleaving a dedicated set of bits that is divided in an appropriate number of blocks using for each block an interleaver matrix with a predefined first dimension for interleaving the bits within each block, whereby said appropriate number of blocks is estimated in such a way that a value of a second dimension of the interleaver matrix that is needed to interleave the bits within each block lies within a dedicated range, a base station (BS1-BS8), a user terminal (T1-T4) and a communication network (CN) therefor.