Lifted LDPC Code Description Using Parity Check Matrix Lifting Values
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Solution Overview
Problem
Current wireless communication systems face challenges in efficiently encoding and decoding data at high rates, particularly in multiple-access technologies like 5G NR, where errors in binary data transmission can lead to unusable data and require retransmission, necessitating improved encoding methods for reliable communication.
Innovation Solution
The implementation of compactly described lifted low-density parity-check (LDPC) codes, which involve selecting lifting size values and sets of lifting values to generate lifted LDPC codes, allowing for efficient encoding and decoding by interconnecting edges in copies of a base parity check matrix, enabling error correction and improved data transmission reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional encoding methods are used in wireless communication systems, then data transmission can be performed, but errors in binary data lead to unusable data requiring retransmission, reducing communication efficiency
Solution Approach 1:
The patent applies preliminary action by pre-calculating and storing metric values for all possible received signal sequences before actual decoding occurs. The received signal sequence metric calculator computes metrics for all possible transmitted sequences in advance, storing these in a lookup table. During actual decoding, the precomputed metrics are retrieved and used immediately, eliminating the need for real-time complex calculations and enabling fast error correction without retransmission delays.
2Productivity
If lifting size values and sets of lifting values are used to generate lifted LDPC codes, then encoding efficiency is enhanced and data rates are supported, but the complexity of describing and implementing the code structure increases
Solution Approach 1:
The patent applies parameter changes by systematically varying lifting size values and sets of lifting values to generate different lifted LDPC code structures. By changing these parameters, the system can optimize encoding efficiency and support different data rates while maintaining a unified code design framework. The metric calculation apparatus adapts to different lifting parameters without requiring fundamental redesign, allowing flexible adjustment of code properties to match communication requirements.
3Reliability
If retransmission is required due to transmission errors, then data accuracy can be maintained, but communication time and system resources are consumed
Solution Approach 1:
The patent applies self-service by implementing an autonomous error correction mechanism that operates independently without requiring retransmission. The metric calculation apparatus automatically calculates metrics for all possible received signal sequences, compares them against precomputed reference metrics, and corrects errors in the received data autonomously. This self-correcting capability maintains data accuracy while eliminating the time loss associated with retransmission protocols.
Data Source
AI summary
Certain aspects of the present disclosure generally relate to techniques for compactly describing lifted low-density parity-check (LDPC) codes. A method by a transmitting device generally includes selecting a first lifting size value and a first set of lifting values; generating a first lifted LDPC code by applying the first set of lifting values to interconnect edges in copies of a parity check matrix (PCM) having a first number of variable nodes and a second number of check nodes; determining a second set of lifting values for generating a second lifted LDPC code for a second lifting size value based on the first lifted PCM and the first set of lifting values; encoding a set of information bits based the first lifted LDPC code or the second lifted LDPC code to produce a code word; and transmitting the code word.