Dynamic Decoding Order Selection in MIMO Successive Interference Cancellation

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Solution Overview

Problem

In MIMO communication systems, determining the optimal decoding order and reconstruction weights for successive interference cancellation is challenging, affecting system performance and throughput due to varying channel conditions and interference from multiple streams.

Innovation Solution

A processor-based apparatus dynamically selects the decoding order and calculates reconstruction weights for MIMO signals, updating the order after each successful decode and subtract operation to maximize decoding performance and throughput.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a fixed decoding order is used for successive interference cancellation, then the processing complexity is reduced, but the decoding performance deteriorates under varying channel conditions

Engineering Contradiction:

Improvedecoding performanceVSAvoidprocessing complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies dynamics by transitioning from a fixed decoding order to a dynamic decoding order that adapts to varying channel conditions. The receiver continuously monitors channel state information and reorders the decoding sequence of multiple data streams based on current channel quality, ensuring optimal decoding performance while maintaining manageable processing complexity through algorithmic optimization.

Inventive Principle:

Principle #15Dynamics

2Reliability

If the decoding order is dynamically adjusted based on channel conditions, then the decoding performance is improved, but the processing time increases

Engineering Contradiction:

Improvedecoding performanceVSAvoidprocessing time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by pre-calculating and storing channel state information and decoding order sequences before actual data decoding occurs. The system prepares multiple possible decoding orders in advance based on predicted channel conditions, allowing rapid selection and execution during time-critical decoding operations, thus reducing real-time processing time while maintaining high decoding performance.

Inventive Principle:

Principle #10Preliminary action

3Productivity

If successive interference cancellation is applied to multiple streams, then the throughput is increased, but the interference cancellation accuracy deteriorates

Engineering Contradiction:

Improvesystem throughputVSAvoidinterference cancellation accuracy

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies local quality by treating each data stream differently in the interference cancellation process. Instead of uniform processing, the system assigns different decoding orders and cancellation strategies to different streams based on their individual channel conditions and interference characteristics. This localized approach enables accurate interference cancellation for each stream while maintaining high overall throughput through parallel processing of multiple streams.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS8711994B2Methods for determining decoding order in a MIMO system with successive interference cancellation

Publication Date: 2014.04.29 QUALCOMM INC

AI summary

Certain aspects provide a method for determining decoding order and reconstruction weights for decoded streams to be cancelled in a MIMO system with successive interference cancellation, based on estimates of the channel characteristics, the received composite signal and parameters of the system.