Variable-Column Polar Code Interleaver for 16-QAM and 64-QAM

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Solution Overview

Problem

Existing wireless communication networks face challenges in achieving sufficient Signal-to-Noise Ratio (SNR) and Block Error Rate (BLER) performance for polar codes, especially under Additive White Gaussian Noise (AWGN), due to inadequate interleaver designs for higher-order modulation schemes like 16-QAM or 64-QAM.

Innovation Solution

A new interleaver design utilizing a right isosceles triangle-shaped or trapezoid-shaped matrix with varying columns between rows, where the number of columns decreases as you move down the rows, is introduced to improve data reliability, replacing traditional interleavers like QPP or sub-block interleavers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional interleavers (QPP or sub-block interleavers) are used for polar codes, then the device complexity is low and ease of manufacture is good, but the SNR performance is insufficient and BLER performance deteriorates under higher-order modulation schemes

Engineering Contradiction:

ImproveSNR performance and BLER performanceVSAvoidinterleaver structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The interleaver is segmented into multiple rows with different column counts, where each row processes a portion of the coded bits independently. This segmentation allows the system to achieve better error correction performance by distributing bits across different interleaving patterns while maintaining manageable complexity through modular row-based processing

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different rows of the interleaver have different local properties (different numbers of columns), creating varied interleaving characteristics for different portions of the data. This local quality variation optimizes performance for specific modulation schemes while keeping the overall structure relatively simple

Inventive Principle:

Principle #3Local quality

2Reliability

If the interleaver uses a fixed number of columns across all rows, then the structure is simple and ease of operation is good, but the performance for higher-order modulation schemes like 16-QAM or 64-QAM is inadequate

Engineering Contradiction:

Improvedata reliability in noisy channelsVSAvoidinterleaver structure simplicity

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The interleaver employs an asymmetric structure where the number of columns varies across different rows, breaking the symmetry of traditional fixed-column interleavers. This asymmetry enables the system to adapt to the specific requirements of higher-order modulation schemes, improving data reliability in noisy channels while maintaining reasonable operational simplicity

Inventive Principle:

Principle #4Asymmetry

Solution Approach 2:

The interleaver parameters (number of columns per row) are changed and optimized for different modulation schemes. This parameter variation allows the same interleaver structure to achieve good performance across multiple modulation types including 16-QAM and 64-QAM without requiring complete redesign

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS10404413B2Efficient interleaver design for polar codes

Publication Date: 2019.09.03 QUALCOMM INC

AI summary

Aspects of the disclosure relate to wireless communication devices configured to encode information blocks to produce code blocks and interleave the code blocks utilizing an interleaver including a plurality of rows and a plurality of columns, where the number of columns of the interleaver varies between the rows. In some examples, the interleaver includes a right isosceles triangle-shaped matrix of rows and columns. In other examples, the interleaver includes a trapezoid-shaped matrix of rows and columns.