Receiver Equalization Using Stochastic Hill Climbing and Genetic Mutation

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Solution Overview

Problem

Existing channel equalization techniques, such as least mean squares (LMS) and brute force search, face challenges in optimizing multiple parameters efficiently, leading to suboptimal solutions and prolonged equalization times due to coupling of parameters and excessive computational requirements.

Innovation Solution

The method employs stochastic gradient hill climbing and genetic mutation operations to optimize parameters for equalization, determining values that maximize the figure of merit of an eye diagram, allowing for efficient adaptation of both receivers and transmitters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If brute force search is used to find optimal parameter combinations, then manufacturing precision of equalization is improved, but loss of time becomes prohibitive

Engineering Contradiction:
Improveequalization precisionVSAvoidequalization time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent segments the equalization process into two distinct phases: a training phase where exhaustive search is performed offline to determine optimal parameter combinations, and a real-time phase where pre-computed lookup tables are used for rapid equalization. This segmentation allows the computationally intensive search to be performed when time is not constrained, while real-time operation benefits from the segmented, pre-processed results.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary action by pre-computing optimal parameter combinations during an offline training phase and storing them in lookup tables. This preliminary computation eliminates the need for time-consuming searches during real-time equalization, as the system can directly retrieve pre-determined optimal parameters from the lookup tables based on measured channel characteristics.

Inventive Principle:
Principle #10Preliminary action

2Device complexity

If multiple parameters are optimized using a single shared cost function, then device complexity is reduced, but manufacturing precision deteriorates due to parameter coupling

Engineering Contradiction:
Improveequalization structureVSAvoidparameter optimization accuracy
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The patent segments the parameter optimization process by treating different equalization parameters (such as CTLE parameters and equalizer tap coefficients) as distinct optimization targets with separate cost functions. This segmentation prevents parameter coupling that would occur with a single shared cost function, allowing each parameter to be optimized independently to its true optimum without being constrained by suboptimal values of other parameters.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the optimization approach by introducing multiple independent cost functions, each tailored to specific parameters or parameter groups. This allows the system to evaluate and optimize different parameters based on their specific impact on signal quality, rather than relying on a single aggregate cost function that may not accurately reflect the optimal settings for individual parameters.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If exhaustive search of all parameter combinations is performed, then manufacturing precision is improved, but productivity decreases due to extended equalization time

Engineering Contradiction:
Improveparameter selection accuracyVSAvoidequalization speed
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent performs preliminary action by conducting exhaustive searches during an offline training phase to build comprehensive lookup tables containing optimal parameter combinations for various channel conditions. This preliminary computation stores the results of what would otherwise be time-consuming searches, enabling rapid retrieval during real-time operation without sacrificing the precision that exhaustive search provides.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent segments the equalization system into an offline training component that performs exhaustive searches to generate lookup tables, and an online operational component that uses these pre-computed tables for rapid parameter selection. This segmentation allows the system to achieve both high precision (through exhaustive search in the training phase) and high productivity (through fast lookup in the operational phase).

Inventive Principle:
Principle #1Segmentation

Data Source

PatentUS11381431B2Receiver and transmitter adaptation using stochastic gradient hill climbing with genetic mutation
Publication Date: 2022.07.05 NVIDIA CORP
  • US11381431B2 patent drawing
  • US11381431B2 patent drawing
  • US11381431B2 patent drawing

AI summary

A receiver receives communications over a communication channel, which may distort an incoming communication signal. In order to counter this distortion, the frequency response of the receiver is manipulated by adjusting several frequency response parameters. Each frequency response parameter controls at least a portion of the frequency response of the receiver. The optimal values for the frequency response parameters are determined by modifying an initial set of values for the frequency response parameters through one or more of stochastic hill climbing operations until a performance metric associated with the receiver reaches a local maximum. The modified values are displaced through one or more mutation operations. The stochastic hill climbing operations may subsequently be performed on the mutated values to generate the final values for the frequency response parameters.