Recursive Block Precoding for Multi-User QoS Tradeoffs
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing precoding techniques in multi-user MIMO systems are sub-optimal due to the need for different modulation and coding schemes and varying quality of service requirements among users, leading to inefficiencies in computational complexity and network overhead.
Innovation Solution
A precoder that groups users based on quality of service indicators and modulation and coding parameters, using a recursive block precoding method to minimize transmit power while supporting diverse user requirements, employing a user ordering and grouping unit, precoding unit, and processing unit to determine optimal perturbation vectors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If non-linear precoding techniques are used to improve system capacity and throughput, then performance is improved, but computational complexity increases significantly
Solution Approach 1:
The invention segments users into different groups based on channel conditions and quality of service requirements. By dividing the user set into multiple groups, the precoding computation can be performed separately for each group, significantly reducing the overall computational complexity while maintaining system capacity benefits of non-linear precoding.
Solution Approach 2:
The invention changes the parameter of precoding computation by using different precoding methods for different user groups. Specifically, it applies non-linear precoding to selected groups of users rather than all users, thereby reducing computational complexity while still achieving performance improvements for the most beneficial user groups.
2Reliability
If different modulation and coding schemes are applied to support varying quality of service requirements, then service quality is improved, but network overhead and computational complexity increase
Solution Approach 1:
The invention segments users into groups based on their quality of service requirements and channel conditions. Each group can be assigned appropriate modulation and coding schemes, allowing differentiated service quality while reducing the computational burden of calculating precoding for all users simultaneously.
Solution Approach 2:
The invention applies local quality by tailoring the precoding computation and modulation/coding scheme selection to the specific requirements of each user group. Instead of using a uniform approach for all users, the system optimizes parameters locally for each group based on their individual quality of service needs and channel characteristics.
3Productivity
If all users are served simultaneously with uniform precoding, then network simplicity is maintained, but performance is sub-optimal due to ignoring diverse user requirements
Solution Approach 1:
The invention segments the user population into multiple groups based on channel conditions and quality of service requirements. This segmentation enables the system to apply optimized precoding strategies to each group, improving overall throughput while managing computational complexity through grouped processing rather than individual user optimization.
Solution Approach 2:
The invention applies partial action by selecting only certain user groups for non-linear precoding optimization rather than attempting to optimize for all users. This approach achieves significant throughput improvements for the most beneficial groups while avoiding the excessive computational complexity that would result from optimizing all users simultaneously.
Data Source
AI summary
A precoder for precoding a vector of information symbols to be sent to a plurality of users, the precoder includes a user ordering and grouping unit configured to group the plurality of users depending on one or more quality of service indicators and on modulation and coding parameters associated with the plurality of users, the user ordering and grouping unit being configured to divide a predefined upper triangular precoding matrix into a plurality of sub-matrices and to divide the vector of information symbols into a plurality of sub-vectors, each sub-vector comprising information symbols to be sent to a group of users, the sub-vectors being arranged according to an arbitrary order of the one or more quality of service indicators; a precoding unit configured to determine a perturbation vector according to the minimization of a transmit power metric, the perturbation vector comprising a plurality of perturbation sub-vectors, each perturbation sub-vector corresponding to a sub-vector of information symbols, the precoding unit being configured to determine an estimate of each perturbation sub-vector by applying a recursive search algorithm.