Blind Channel Impulse Response Combining for TD-SCDMA Noise Mitigation

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Solution Overview

Problem

In TD-SCDMA receivers, channel estimation quality is compromised in default midamble allocation mode due to insufficient power allocation to each training sequence, especially when multiple channelization codes are assigned to a user equipment, and there is a lack of information about training sequence allocations from neighboring cells, hindering effective noise mitigation.

Innovation Solution

Applying a correlation function to pairs of channel impulse response windows to identify and group those with high correlation as belonging to the same user equipment, and combining their channel estimation results using maximum ratio combining to mitigate noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple training sequences are transmitted simultaneously for default midamble allocation mode, then more user equipments can be served, but the power allocated to each training sequence decreases and channel estimation quality deteriorates

Engineering Contradiction:

Improvenumber of user equipments servedVSAvoidchannel estimation quality

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent combines multiple channel impulse response windows from the same user equipment that occupy multiple channelization codes. By correlating CIR windows and identifying those with high correlation coefficients, the system merges their channel estimation results through maximum ratio combining, thereby improving channel estimation quality while maintaining the ability to serve multiple user equipments simultaneously.

Inventive Principle:

Principle #5Merging (Combining)

2Measurement precision

If channel impulse response windows from non-desired user equipments are combined for noise mitigation, then channel estimation quality improves, but the complexity of identifying and grouping CIR windows increases

Engineering Contradiction:

Improvechannel estimation qualityVSAvoidcomplexity of identifying and grouping CIR windows

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex information-based identification methods with a correlation-based approach. Instead of requiring detailed knowledge of midamble sequence allocations from neighboring cells, the system uses correlation functions to automatically identify and group CIR windows from the same user equipment. This substitution of the identification mechanism reduces system complexity while maintaining the ability to perform noise mitigation through combining.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS8929344B2Method and system for blind channel impulse response combining for noise mitigation in channel estimation in a TD-SCDMA receiver

Publication Date: 2015.01.06 MEDIATEK SINGAPORE PTE LTD

AI summary

Blind channel impulse response combining for noise mitigation in channel estimation in a TD-SCDMA receiver includes applying a correlation function to pairs of channel impulse response windows associated with non-desired user equipments, grouping all those channel impulse response windows having a correlation function above a predetermined threshold as identified with the same user equipment, and combining the channel estimation results from each identified user equipment in the group to mitigate noise.