Time-Frequency Resource Mapping for Bursty Interference Decoding
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Solution Overview
Problem
Wireless communication systems, particularly LTE/LTE-Advanced, face interference challenges in unlicensed spectrum due to bursty interference from short-duration packets and uplink UE transmissions, leading to increased re-transmissions and reduced network performance.
Innovation Solution
The implementation of time-frequency transmission techniques, including interleaving and re-transmission strategies, where code blocks are spread across a larger time-frequency grid and re-mapped during re-transmissions, along with layered coding to enhance decoding efficiency and interference cancellation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If code blocks are transmitted sequentially in a fixed order, then the transmission structure is simple and easy to decode, but bursty interference can cause multiple code blocks to be lost simultaneously, increasing re-transmissions
Solution Approach 1:
The patent segments code blocks into different groups and transmits them in interleaved sequences rather than sequential order. This segmentation allows interference to affect only specific segments while other segments remain intact, reducing the need for re-transmissions and improving reliability without significantly increasing complexity
Solution Approach 2:
The patent introduces a new dimension to code block transmission by using multiple transmission sequences and interleaving patterns. Instead of transmitting code blocks in a single sequential order, the system uses dimensional interleaving across different sequences, which disperses interference effects and improves decoding success rates
2Productivity
If code blocks are concentrated in specific time-frequency resources, then the transmission efficiency is high, but bursty interference in those resources causes complete loss of multiple code blocks, increasing re-transmissions
Solution Approach 1:
The patent segments code blocks and distributes them across different time-frequency resources using interleaved sequences. This segmentation prevents concentration of multiple code blocks in a single interference-prone resource, maintaining transmission efficiency while improving interference resistance through spatial and temporal distribution
Solution Approach 2:
The patent applies different transmission sequences and interleaving patterns to different code block groups, creating local variations in resource allocation. This local quality approach ensures that interference affecting one local region does not propagate to other regions, maintaining overall transmission efficiency while providing localized interference protection
3Device complexity
If re-transmissions use the same code block sequence, then the transmission process is simple, but repeated interference at the same resources causes continuous decoding failures
Solution Approach 1:
The patent implements dynamic code block sequencing for re-transmissions, where the transmission sequence is changed based on interference patterns and decoding feedback. This dynamic approach allows the system to adapt to varying interference conditions, preventing continuous decoding failures without requiring complex re-transmission protocols
Solution Approach 2:
The patent uses decoding feedback to determine the transmission sequence for re-transmissions. When decoding failures occur, the system receives feedback and adjusts the code block sequencing accordingly, creating a feedback loop that continuously optimizes transmission reliability while maintaining relatively simple re-transmission processes
Data Source
AI summary
Resource mapping and coding schemes to handle bursty interference are disclosed that provide for spreading the modulated symbols for one or more transmission code words over more symbols in the time-frequency transmission stream. Certain aspects allow for the modulated symbols to be based on bits from more than one code word. Other aspects also provide for re-mapping code word transmission sequences for re-transmissions based on the number of re-transmissions requested by the receiver. Additional aspects provide for layered coding that uses a lower fixed-size constellation to encode/decode transmissions in a layered manner in order to achieve a larger-size constellation encoding. The layered encoding process allows the transmitter and receiver to use different coding rates for each coding layer. The layered encoding process also allows interference from neighboring cells to be canceled without knowledge of the actual constellation used to code the interfering neighboring signal.