OTFS Iterative De-interference Decoding for Multi-User Reliability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In Orthogonal Time Frequency Space (OTFS) systems, existing Linear Minimum Mean Square Error (LMMSE) equalizers cannot effectively eliminate inter-user interference caused by delay spread and Doppler spread among multiple transmitting terminals, which affects the reliability of multi-user uplink access systems.
Innovation Solution
The implementation of iterative serial de-interference decoding in both the Doppler and delay dimensions, where delay-Doppler regions are divided into sets based on shift intervals, allowing for sequential decoding and interference elimination, thereby improving transmission reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If LMMSE equalizer is used for channel equalization in time-frequency domain, then channel equalization is achieved, but inter-user interference caused by delay spread and Doppler spread cannot be eliminated
Solution Approach 1:
The patent segments the delay-Doppler regions into multiple sets based on different shift intervals occupied by different transmitting terminals. This segmentation allows the receiving terminal to perform iterative serial de-interference decoding on each set separately, eliminating inter-user interference while maintaining manageable computational complexity through structured processing.
Solution Approach 2:
The patent extends the equalization process from the time-frequency domain to the delay-Doppler domain by performing iterative serial de-interference decoding in both delay and Doppler dimensions. This dimensional transition enables the system to eliminate inter-user interference that cannot be addressed in the traditional time-frequency domain alone.
2Reliability
If iterative serial de-interference decoding is performed in both Doppler and delay dimensions, then inter-user interference is eliminated, but computational complexity increases
Solution Approach 1:
The patent divides delay-Doppler regions into multiple sets based on shift intervals, allowing iterative serial de-interference decoding to be performed on each set separately. This segmentation reduces the overall computational complexity by breaking down the complex de-interference operation into smaller, manageable subsets that can be processed sequentially.
Solution Approach 2:
The patent performs iterative serial de-interference decoding partially by processing one dimension at a time (first dimension, then second dimension) rather than simultaneously processing both delay and Doppler dimensions together. This partial action approach reduces computational complexity while still achieving effective interference elimination.
Data Source
AI summary
An apparatus for wireless communication includes: a receiving unit, for receiving a first orthogonal time-frequency space symbol including multiple delay Doppler regions corresponding to multiple transmitting terminals; a processing unit, for executing the following steps: A1: dividing the multiple delay Doppler regions into multiple first-type sets according to different displacement intervals occupied in a first dimension, and performing iterative serial de-interference decoding on the multiple time-delay Doppler regions in a same first-class set; A2: dividing the multiple delay Doppler regions into multiple second-type sets according to different displacement intervals occupied in a second dimension, and performing iterative serial de-interference decoding on the multiple time-delay Doppler regions in a same second-class set. The first dimension is one of a delay dimension and a Doppler dimension, and the second dimension is the other dimension of the two dimensions.