Non-linear Equalizer for Wireless Receiver Signal Compensation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Wireless communication systems face challenges in accurately recovering transmitted signals due to both linear and non-linear distortions introduced along the transmission path, which existing technologies often fail to fully compensate for, especially when non-linear effects from transmitter power amplifiers are present.

Innovation Solution

A receiver device employs a non-linear equalizer, trained using a known training sequence, to correct non-linear distortions, and can also update parameters for a linear equalizer to address linear distortions, allowing for improved signal recovery without requiring complex digital pre-distortion at the transmitter.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If digital pre-distortion is implemented at the transmitter to mitigate non-linear effects, then non-linear distortion compensation is improved, but device complexity increases

Engineering Contradiction:

Improvenon-linear distortion compensationVSAvoidtransmitter complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

Instead of applying pre-distortion at the transmitter to compensate for non-linearities, this patent applies post-distortion (equalization) at the receiver to invert and compensate for the non-linear distortion effects. The non-linear equalizer at the receiver processes the distorted signal to recover the original transmitted signal, thereby solving the compensation problem while keeping the transmitter simple.

Inventive Principle:

Principle #13The other way round (Inversion)

2Device complexity

If only linear equalization is used to correct channel distortions, then device complexity is kept low, but non-linear distortion compensation is insufficient

Engineering Contradiction:

Improveequalizer complexityVSAvoidsignal recovery accuracy

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The equalization function is segmented into two distinct components: a linear equalizer that handles linear channel distortions and a non-linear equalizer that handles non-linear distortions from the power amplifier. This segmentation allows each equalizer to be optimized for its specific function, with the linear equalizer maintaining simplicity and the non-linear equalizer providing enhanced compensation capability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The equalization system uses a composite approach by combining linear and non-linear equalization techniques into a unified receiver structure. The linear equalizer addresses frequency-dependent magnitude and phase variations, while the non-linear equalizer addresses amplitude-to-amplitude and amplitude-to-phase distortions, creating a composite solution that handles both types of channel impairments.

Inventive Principle:

Principle #40Composite materials

3Measurement precision

If complex non-linear equalization processing is applied at the receiver, then signal recovery accuracy is improved, but processing time increases

Engineering Contradiction:

Improvesignal recovery accuracyVSAvoidprocessing time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The linear equalizer performs preliminary equalization of the received signal, correcting linear distortions before the non-linear equalizer processes the signal. This preliminary action reduces the complexity of the subsequent non-linear equalization task, as the signal has already been partially restored, thereby reducing overall processing time while maintaining accuracy.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The non-linear equalizer focuses on compensating only for the specific non-linear distortion components that remain after linear equalization, rather than attempting to correct all types of distortions. This partial action approach concentrates processing resources on the most critical non-linear effects, achieving sufficient accuracy without excessive processing overhead.

Inventive Principle:

Principle #16Partial or excessive action

Data Source

PatentUS11258639B2Non-linear equalizer in communication receiver devices

Publication Date: 2022.02.22 NANOSEMI INC

AI summary

Disclosed are methods, systems, devices, apparatus, media, design structures, and other implementations, including a method is that includes receiving, at a receiver device, a signal transmitted from a remote wireless device, with the signal including a training sequence, and updating, based on the training sequence, one or more adjustable characteristics for a non-linear equalizer of the receiver device, with the one or more adjustable characteristics controlling signal non-linear compensation processing to correct non-linear distortions affecting communication signals transmitted from the remote wireless device. In some embodiments, the method may further include updating, based on the training sequence, additional one or more adjustable characteristics for a linear equalizer of the receiver device, with the additional one or more adjustable characteristics controlling signal linear compensation processing to correct linear distortions affecting the communication signals.