Channel Estimation Using Interference Reference Signals

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Solution Overview

Problem

Existing wireless communication systems face challenges in channel estimation and data detection due to inter-cell interference, which affects the accuracy of channel estimates and data demodulation, especially in LTE systems where multiple antenna techniques are used.

Innovation Solution

The proposed solution involves a method for channel estimation and data detection that suppresses co-channel interference by using reference signals (RS) and advanced signal processing techniques, such as MMSE estimation and data detection algorithms, to accurately estimate channel weights and interpolate data symbols, even in the presence of inter-cell interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If traditional channel estimation methods are used in LTE systems with multiple antenna techniques, then the system can support advanced features and higher data throughput, but the accuracy of channel estimation and data detection deteriorates due to inter-cell interference

Engineering Contradiction:

Improvedata throughput rateVSAvoidchannel estimation accuracy

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The patent applies interference cancellation techniques to convert the harmful inter-cell interference into a manageable component. By estimating and subtracting the interference signal from the received signal, the system transforms the harmful interference into a corrected signal that improves channel estimation accuracy while maintaining support for advanced LTE features and high data throughput rates

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent changes the estimation parameters by using enhanced minimum mean square error (MMSE) estimation that incorporates interference covariance information. This parameter change in the estimation algorithm allows the system to maintain high data throughput with multiple antenna techniques while improving channel estimation accuracy by accounting for inter-cell interference characteristics

Inventive Principle:

Principle #35Parameter changes

2Measurement precision

If advanced signal processing techniques are used to suppress inter-cell interference, then channel estimation accuracy improves, but computational complexity increases

Engineering Contradiction:

Improvechannel estimation accuracyVSAvoidsignal processing complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies preliminary interference cancellation by estimating and removing inter-cell interference before performing channel estimation. This preliminary action simplifies the subsequent channel estimation process by reducing the interference component in the received signal, thereby improving accuracy while managing computational complexity through a two-stage approach

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent segments the received signal processing into distinct stages: interference estimation, interference cancellation, and channel estimation. This segmentation allows each stage to be optimized independently, improving overall channel estimation accuracy while keeping the computational complexity of each individual stage manageable

Inventive Principle:

Principle #1Segmentation

3Reliability

If reference signals are used for channel estimation in the presence of co-channel interference, then data detection reliability can be improved, but the bit error rate increases due to interference contamination

Engineering Contradiction:

Improvedata detection reliabilityVSAvoidbit error rate

Core Design Contradiction:

ReliabilityVSLoss of information

Solution Approach 1:

The patent applies interference cancellation to convert the harmful co-channel interference that contaminates reference signals into a corrected reference signal. By estimating and removing the interference component from the received reference signals, the system improves data detection reliability while reducing the bit error rate that would otherwise result from interference contamination

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Data Source

PatentEP2534870B1Channel estimation and data detection in a wireless communication system in the presence of inter-cell interference

Publication Date: 2020.04.22 BLACKBERRY LTD

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AI summary

Channel estimation and data detection in a wireless communication system in the presence of inter-cell interference is provided. In one embodiment, a method for channel estimation and data detection in a wireless communication system, comprising receiving a signal, wherein said signal is composed of a data signal, a desired reference signal and an interference reference signal; selecting a channel estimator using said desired reference signal, said interference reference signal or both; applying said selected channel estimator to said desired reference signal, said interference reference signal or both to generate one or more reference signal channel estimate weights; generating one or more data channel estimate weights using said reference signal channel estimate weights; selecting a data detector using said reference signal channel estimate weights, said data channel estimate weights or both; and detecting said data signal using said selected data detector, wherein said selected data detector uses said reference signal channel estimate weights, said data channel estimate weights or both.