Transmitter Shortening Pattern for LDPC BER and FER Stability
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Solution Overview
Problem
Current digital broadcasting systems face challenges in providing improved performance, particularly in terms of bit error rate (BER) and frame error rate (FER), due to limitations in signal transmission and reception methods.
Innovation Solution
A transmitter is designed with an outer encoder, zero padder, and LDPC encoder to encode input bits, pad zero bits based on a predetermined shortening pattern, and divide LDPC information bits into bit groups to improve BER and FER performance by strategically positioning these bits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If zero bits are padded to LDPC information bits using conventional methods, then the code length is shortened, but the bit error rate (BER) and frame error rate (FER) performance deteriorates
Solution Approach 1:
The LDPC information bits are divided into multiple bit groups, and zero bits are padded to specific bit groups based on a predetermined shortening pattern. This segmentation approach allows selective shortening of certain bit groups while preserving the integrity and error correction capability of other groups, thereby maintaining BER and FER performance during code length shortening.
Solution Approach 2:
Different bit groups are treated differently through selective zero-padding based on the shortening pattern. Certain bit groups are padded with zero bits while others are not, creating local variations in the code structure that optimize both error correction performance and code length reduction. This local differentiation resolves the contradiction by applying shortening only where it does not harm reliability.
2Length of stationary object
If zero bits are padded to all bit groups, then the code length is reduced, but the manufacturing precision of the bit positioning deteriorates
Solution Approach 1:
A predetermined shortening pattern is established before the actual encoding process. This pattern specifies which bit groups should receive zero bits and which should not, allowing the system to pre-plan the shortening operation to maintain optimal bit group positioning and avoid degradation in positioning precision while achieving code length reduction.
Data Source
AI summary
A transmitter is provided. The transmitter includes: an outer encoder configured to encode input bits to generate outer-encoded bits including the input bits and parity bits; a zero padder configured to constitute Low Density Parity Check (LDPC) information bits including the outer-encoded bits and zero bits; and an LDPC encoder configured to encode the LDPC information bits, wherein the LDPC information bits are divided into a plurality of bit groups, and wherein the zero padder pads zero bits to at least some of the plurality of bit groups, each of which is formed of a same number of bits, to constitute the LDPC information bits based on a predetermined shortening pattern which provides that the some of the plurality of bit groups are not sequentially disposed in the LDPC information bits.