OFDM Receiver Circuit Excluding Middle Samples

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current receiver circuits for OFDM signals face challenges in accurately demodulating and decoding due to co-channel interference and noise, particularly in hybrid and all-digital IBOC modes, where conventional averaging techniques that include middle-sample-values can degrade channel-state information and bit error rates.

Innovation Solution

The proposed receiver circuit employs an averaging-processing-block that excludes the middle-sample-value from the averaging operation for channel-estimate and noise-estimate calculations, using extrinsic information averaging techniques to improve channel-state information and bit error rates, and incorporates a virtual-pilot-signal-generator to enhance data-decision directed channel-state information computation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional averaging techniques including middle-sample-values are used, then the averaging operation is simpler, but channel-state information and bit error rates deteriorate

Engineering Contradiction:
Improvechannel-state information accuracyVSAvoidaveraging operation complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts and excludes the middle-sample-value from the averaging operation. Specifically, when calculating averaged channel estimates or noise estimates, the method deliberately omits the middle sample (corresponding to the pilot symbol position) from the averaging process, using only the lower and upper sample groups. This extraction of the problematic middle-sample-value resolves the contradiction by improving measurement precision without requiring complex iterative decoding.

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If iterative decoding and higher-layer information reuse are employed, then bit error rates improve, but device complexity increases

Engineering Contradiction:
Improvebit error rateVSAvoiddecoding complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent employs a simple, non-iterative averaging operation that excludes middle samples as a disposable, low-complexity processing step. Instead of using complex iterative decoding algorithms or reusing higher-layer information, the method applies a straightforward averaging operation on selected samples that provides sufficient error rate performance without the computational burden of iterative processes.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Data Source

PatentEP3276900B1A receiver circuit
Publication Date: 2020.02.19 NXP BV
  • EP3276900B1 patent drawingFigure 1~2
  • EP3276900B1 patent drawingFigure 3~6
  • EP3276900B1 patent drawingFigure 5

AI summary

A receiver circuit comprising an averaging-processing-block that is configured to receive an OFDM signal. The OFDM signal comprises a plurality of sample-values, wherein the sample-values comprise: a middle-sample-value; a lower-sample-value-group; and a higher-sample-value-group. The averaging-processing-block can determine an averaged-sample-value for the middle-sample-value by performing an averaging operation on the sample-values of the lower-sample-value-group and the higher-sample-value-group, but not on the middle-sample-value.