Probabilistic Amplitude Shaping Boundary Encoding for High-MCS Decoding
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Solution Overview
Problem
Existing wireless communication technologies face challenges in achieving high throughput and low latency due to the gap between achievable channel capacity with LDPC encoding and the Shannon bound, particularly with high MCSs like 1024-QAM and 4096-QAM, which require high SNR conditions that are difficult to maintain.
Innovation Solution
Implementing prefix encoding and decoding operations to identify and indicate boundaries in bitstreams, using amplitude bits to mark boundaries and align data units, and inserting padding bits to ensure integer multiples of fixed-length segments for accurate decoding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If LDPC encoding is used to achieve high MCSs like 1024-QAM and 4096-QAM, then throughput can be improved, but the gap to Shannon bound increases and high SNR requirements make reliable transmission difficult
Solution Approach 1:
The information bits are divided into multiple data units, each independently encoded with prefix encoding. This segmentation allows boundary identification and independent decoding of each data unit, improving reliability while maintaining high throughput through efficient use of high MCSs.
Solution Approach 2:
Boundary indication bits are inserted at the beginning of each data unit before encoding. This preliminary action enables the receiver to accurately identify data unit boundaries and perform synchronized decoding, ensuring reliable transmission even at high data rates with high MCSs.
2Measurement precision
If prefix encoding with boundary indication is implemented, then data unit boundary identification is improved, but device complexity increases
Solution Approach 1:
Instead of using complex global synchronization mechanisms, the patent applies local boundary indication by inserting specific bit patterns at the start of each data unit. This local approach simplifies the overall system complexity while maintaining high boundary identification accuracy through straightforward pattern matching at the receiver.
Solution Approach 2:
Boundary indication bits serve as an intermediary element between the information bits and the encoded output. These intermediary bits carry boundary information without requiring complex processing, enabling accurate data unit identification while keeping the encoding and decoding operations relatively simple.
3Measurement precision
If padding bits are added to align data units to integer multiples of fixed-length segments, then decoding accuracy is improved, but loss of information increases
Solution Approach 1:
The patent changes the parameter of data unit length by adding padding bits to align with fixed-length segments. This parameter adjustment ensures that each data unit can be independently and accurately decoded, and the overhead is minimized by using efficient alignment rather than excessive padding.
Data Source
AI summary
This disclosure provides methods, devices and systems for amplitude shaping encoding, and specifically, for indicating boundaries in bitstreams encoded using amplitude shaping encoding. In some aspects, a transmitting device may insert, into an bitstream to indicate a boundary, a sequence of amplitude bits not associated with any patterns of bit values in a lookup table used for the encoding. In some other aspects, a transmitting device may monitor a length of the amplitude bits in a bitstream during the encoding and stop the encoding on information bits at an end of a current data unit responsive to the length reaching a threshold. In some other aspects, a transmitting device may monitor the length of the information bits and, for each data unit, determine whether a boundary is or would be reached. Responsive to determining that a boundary is or would be reached, the transmitting device may not include, before the boundary, any amplitude bits generated based on the information bits in the data unit, and instead add padding bits after a last amplitude bit before the boundary.