Interference Network Coding With Sliding-Window Superposition Decoding
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Solution Overview
Problem
Existing communication systems face performance degradation in dense wireless networks due to interference, as conventional point-to-point channel codes treat interference as noise, leading to high computational complexity in simultaneous decoding.
Innovation Solution
The sliding-window superposition coding (SWSC) scheme combines block Markov coding, superposition coding, and successive cancellation decoding to achieve the performance of simultaneous decoding with low complexity, using point-to-point channel codes for general interference channels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If simultaneous decoding is used to achieve optimal performance in interference channels, then the achievable rate region is improved, but the computational complexity increases significantly
Solution Approach 1:
The patent segments the decoding process into two distinct stages: first decoding the desired signal, then decoding the interfering signal. This segmentation avoids the need for high-complexity multiuser sequence detection while achieving the same rate region as simultaneous decoding. The receiver processes signals in a sequential manner rather than jointly, reducing computational burden.
Solution Approach 2:
The patent applies preliminary action by having the receiver first decode the desired signal before attempting to decode the interfering signal. This preliminary decoding step simplifies the subsequent interference decoding process, as the receiver already has information about the desired signal structure and can use it to aid in interference cancellation and decoding.
2Device complexity
If treating interference as noise is used to reduce computational complexity, then the device complexity is reduced, but the performance degrades as interference becomes stronger
Solution Approach 1:
The patent converts the harmful interfering signal into a beneficial resource by having the receiver decode it. Instead of treating interference as unwanted noise that degrades performance, the system decodes the interfering signal to recover useful information, thereby improving the achievable rate region while maintaining low computational complexity through sequential decoding.
3Device complexity
If successive cancellation decoding is used to achieve low computational complexity, then the device complexity is reduced, but the achievable rate region is strictly smaller than simultaneous decoding
Solution Approach 1:
The patent introduces dynamics by allowing the receiver to adaptively choose between different decoding orders based on channel conditions and signal strengths. The system can dynamically switch between decoding the desired signal first or decoding the interfering signal first, optimizing performance for different interference scenarios while maintaining the low-complexity sequential decoding structure.
Data Source
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Figure 3A~3C
AI summary
The disclosed techniques allow for transmitting a signal stream from a sender to a receiver in an environment including multiple senders and receivers. The technique for the sender decomposes a data stream from the sender into multiple substreams, encodes a substream by a codeword, further superimposes multiple codewords to form a signal stream in an asynchronous manner, and transmits the signal stream to the receiver. A codeword can span over multiple blocks. The receiver receives a first codeword stream from a first sender, receives a second codeword stream from a second sender, the two codeword streams may be received at the same time as one signal, and decodes the first codeword stream and second codeword stream over a sliding window of multiple blocks.