Channel Estimation Circuit with Feedback Loop for Dynamic Tracking

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Solution Overview

Problem

Existing channel estimation methods in wireless communication systems, such as OFDM, face challenges in accurately tracking dynamic channel variations, which can lead to reduced precision in channel estimation and communication quality.

Innovation Solution

A channel estimation circuit and method that continuously updates channel estimation values by using the channel estimation result to recover transmission signals, incorporating a signal recovery circuit, channel estimator, time domain filter, and frequency domain filter, and employing a threshold-based comparison to ensure accurate channel tracking and prevent incorrect estimation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional channel estimation method using only pilot signals is used, then the device complexity is low, but the measurement precision of channel estimation deteriorates when channel status varies dynamically

Engineering Contradiction:
Improvechannel estimation precisionVSAvoidchannel estimation circuit complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent implements feedback by using the channel estimation result to recover the transmission signal, then feeding back this recovered signal to perform iterative channel estimation. The channel estimation circuit continuously updates the channel estimation value by comparing the recovered signal with the original pilot signal, creating a closed-loop feedback system that tracks channel variations dynamically and improves estimation precision without requiring additional hardware complexity

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The channel estimation circuit performs self-service by using its own output (channel estimation result) to improve its own performance. The recovered transmission signal from the channel estimation result is reused as input for the next iteration of channel estimation, allowing the system to automatically track and adapt to channel variations without external intervention or additional complex circuitry

Inventive Principle:
Principle #25Self-service

2Measurement precision

If channel estimation is performed continuously to track channel variations, then the measurement precision improves, but the loss of time for processing increases

Engineering Contradiction:
Improvechannel estimation precisionVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent achieves continuous channel estimation by processing each received signal (pilot or data) immediately upon reception. The channel estimation circuit continuously updates the channel estimation value with each incoming signal, performing time-domain and frequency-domain filtering in real-time without interruption. This continuous processing ensures the channel estimation remains current while minimizing processing delays through efficient iterative computation

Inventive Principle:
Principle #20Continuity of useful action

3Reliability

If the channel estimation value is updated frequently to track channel variations, then the reliability of communication improves, but the use of energy increases

Engineering Contradiction:
Improvecommunication reliabilityVSAvoidenergy consumption of channel estimation circuit
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent recovers and reuses the channel estimation result for multiple purposes: it recovers the transmission signal from the channel estimation value, uses the recovered signal for next iteration channel estimation, and applies time-domain and frequency-domain filtering to refine the estimation. This recovery and reuse of information reduces the need for additional energy-consuming operations while maintaining high communication reliability through frequent updates

Inventive Principle:
Principle #34Discarding and recovering

Data Source

PatentEP3503486B1Channel estimation circuit and channel estimation method thereof
Publication Date: 2020.07.29 ALI CORP
  • EP3503486B1 patent drawingFigure 1
  • EP3503486B1 patent drawingFigure 2
  • EP3503486B1 patent drawingFigure 3A

AI summary

A channel estimation circuit (1) includes a signal recovery circuit (10), a channel estimator (13), a time domain filter (14) and a frequency domain filter (15). The signal recovery circuit (10) receives an input signal (Sin), and recovers a transmission signal (Str) of the input signal (Sin). The channel estimator (13) coupled to the signal recovery circuit (10) obtains an estimation signal (Sls) according to the input signal (Sin) and the transmission signal (Str). The time domain filter (14) coupled to the channel estimator (13) performs time domain filtering on the estimation signal (Sls). The frequency domain filter (15) coupled to time domain filter (14) performs frequency domain filtering on the estimation signal (Sls) filtered by the time domain filter (14) to generate a channel estimation result (CH). The channel estimation result (CH) is further transmitted to the channel estimator (13) and the signal recovery circuit (10).