MIMO Signal Subgroup Splitting for Low-Complexity Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional detectors for user equipment in wireless communication networks face high complexity and poor performance, especially in large MIMO systems, due to the exponential complexity of Maximum Likelihood Detection (MLD) and sub-optimal performance of Linear Minimal Mean Square Error (LMMSE) receivers, which are exacerbated by varying channel conditions and modulation types.
Innovation Solution
A method and user equipment that split received MIMO signals into disjoint subgroups, allowing for simultaneous detection using MLD, with an intelligent splitting scheme based on achievable information data rates and interference cancellation, reducing computational complexity and improving performance through Log-Likelihood Ratio combination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If Maximum Likelihood Detection (MLD) is used for detecting transmitted signals in large MIMO systems, then detection performance is improved, but computational complexity increases exponentially
Solution Approach 1:
The patent divides the transmitted signal into G disjoint subgroups, where each subgroup contains a subset of the total layers. By performing MLD separately on each subgroup rather than on all layers simultaneously, the exponential complexity is reduced from O(M^L) to G × O(M^(L/G)), where M is the modulation order and L is the number of layers. This segmentation allows the system to maintain good detection performance while making the computational complexity manageable for large MIMO systems.
2Device complexity
If Linear Minimal Mean Square Error (LMMSE) receivers are used to reduce complexity, then computational complexity is reduced, but detection performance deteriorates
Solution Approach 1:
The patent applies segmentation by dividing the signal into subgroups and applying MLD to each subgroup. This hybrid approach combines the low complexity of group-based processing with the high performance of MLD, achieving a balance between complexity and performance that neither pure LMMSE nor full MLD can achieve alone.
Solution Approach 2:
The patent applies different detection strategies to different parts of the signal. By performing MLD on smaller subgroups rather than uniform processing of all layers, the system achieves locally optimized detection quality in each subgroup while maintaining overall system feasibility. This local quality approach allows MLD to be applied where it provides the most benefit without incurring the full exponential cost.
3Productivity
If the number of MIMO layers is increased to achieve high spectral efficiency, then data rate is improved, but detection complexity increases exponentially
Solution Approach 1:
The patent enables support for a large number of MIMO layers by segmenting the detection process into G subgroups. This allows the system to scale to high spectral efficiency scenarios (e.g., 8×8 MIMO, 16×16 MIMO) without the detection complexity becoming prohibitive, as each subgroup processes fewer layers independently.
Solution Approach 2:
The patent applies MLD partially to each subgroup rather than to the entire signal. By performing MLD on subsets of layers (partial action) rather than all layers at once, the system achieves sufficient detection performance for each group while keeping the overall computational burden acceptable for large MIMO configurations.
Data Source
AI summary
A user equipment (UE) and a method are presented. The UE comprises a receiver unit and a processing circuit, and is configured for receiving wireless signals. The processing circuit is arranged for performing pre-detection of the received signals providing an initial estimation of transmitted signals. The processing circuit is also arranged for splitting the transmitted signal into disjoint subgroups, each one covering a subgroup of all layers used for the transmitted signal such that the subgroups together cover all the layers. The processing circuit is also arranged for interference cancellation performed on the subgroups of transmitted signals based on the initial estimation of the transmitted signals. The processing circuit is also arranged for detection of the subgroups of transmitted signals by utilization of an MLD algorithm, wherein the subgroup of layers within each one of the subgroups of transmitted signals is detected simultaneously.