DFE-Based Channel State Information for ML MIMO Receivers

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Solution Overview

Problem

Predicting the performance of maximum likelihood (ML) multiple input multiple output (MIMO) receivers is computationally intensive and existing methods either fail to fully exploit their capabilities or are impractical, leading to inefficient modulation and coding schemes that result in wasted bandwidth.

Innovation Solution

Employing decision feedback equalization (DFE) to determine channel state information (CSI) for ML MIMO receivers, which allows for more accurate decoding and selection of optimal modulation and coding schemes based on DFE-determined channel characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If decision feedback equalization is used to determine channel state information, then channel utilization and throughput are improved, but computational complexity increases

Engineering Contradiction:
ImprovethroughputVSAvoidcomputational complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The DFE processor performs channel state information determination as part of its normal signal processing function, eliminating the need for separate, dedicated CSI estimation mechanisms. The equalizer uses its own internal computations to serve dual purposes: signal equalization and channel characterization.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The DFE processor is designed to perform multiple functions simultaneously: it equalizes the received signal, determines channel state information, and provides feedback for MCS selection. This multi-functional approach consolidates what would otherwise require separate processing blocks into a single integrated unit.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Device complexity

If linear receiver methods are used to approximate ML MIMO performance, then computational complexity is reduced, but prediction accuracy deteriorates

Engineering Contradiction:
Improvecomputational complexityVSAvoidperformance prediction accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The system uses the actual DFE-processed signal characteristics and decoding performance feedback to accurately determine channel state information and select appropriate modulation and coding schemes. This feedback mechanism allows the system to adapt to real channel conditions rather than relying on simplified predictions.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

Channel state information is determined in advance using DFE processing of pilot or reference signals before actual data transmission begins. This preliminary characterization of the channel allows the system to optimize subsequent data transmission parameters without requiring complex real-time analysis.

Inventive Principle:
Principle #10Preliminary action

3Productivity

If more aggressive modulation and coding schemes are selected, then throughput increases, but error rates increase when channel conditions are not accurately known

Engineering Contradiction:
ImprovethroughputVSAvoiddecoding reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The modulation and coding scheme is dynamically adjusted based on real-time channel state information determined by DFE processing. The system can transition between different MCS levels depending on current channel conditions, optimizing the balance between throughput and reliability rather than being locked into a fixed scheme.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system replaces traditional, static MCS selection mechanisms with a dynamic, feedback-driven approach that uses DFE-based channel characterization. This substitution allows for more intelligent and adaptive MCS selection that responds to actual channel conditions rather than following predetermined patterns.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS9048893B1Determining channel information using decision feedback equalization
Publication Date: 2015.06.02 MARVELL ASIA PTE LTD
  • US9048893B1 patent drawing
  • US9048893B1 patent drawing
  • US9048893B1 patent drawing

AI summary

In various embodiments, the present disclosure provides transmitters, receivers, and methods of determining channel state information for a maximum likelihood (ML) multiple input multiple output (MIMO) receiver, as well as transmitting and demodulating signals based on the determined channel state information. A ML MIMO receiver receives a first MIMO signal from a MIMO transmitter. Channel characteristics of the first MIMO signal are determined based on decision feedback equalization (DFE) processing. The DFE-determined channel characteristics, or information derived from the DFE-determined channel characteristics, are reported to the MIMO transmitter and the MIMO ML receiver decodes a second MIMO signal based on ML processing. The second MIMO signal is modulated and encoded by the MIMO transmitter according to a modulation and coding scheme in accordance with (1) the DFE-determined channel characteristics or (2) the information derived from the DFE-determined channel characteristics.