QPSK Correlation Computation Grouping Circuit

Solution Overview

Problem

Existing GNSS receivers require a high number of accumulations for correlation computation between a data sequence and both in-phase and quadrature code sequences, leading to increased computation complexity and power consumption.

Innovation Solution

A method and apparatus that perform efficient correlation computation by grouping data samples according to in-phase and quadrature code sequences, reducing the number of accumulations required through a combination of grouping and accumulation operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional QPSK correlator designs are used (BPSK-channel-combining or coherent-QPSK-combining), then the correlation result can be obtained, but the number of accumulations increases (2N or 4N), leading to increased computation complexity and power consumption

Engineering Contradiction:

Improvecorrelation result accuracyVSAvoidcomputation complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the QPSK correlation computation into distinct in-phase (I) and quadrature (Q) component processing paths. By separating the correlation computation into independent I and Q components, each processed through dedicated correlation units, the system avoids the need for complex combined processing while maintaining accurate correlation results. This segmentation reduces the accumulation count from 2N or 4N to N by eliminating redundant computations between components.

Inventive Principle:

Principle #1Segmentation

2Measurement precision

If traditional QPSK correlator designs are used (BPSK-channel-combining or coherent-QPSK-combining), then the correlation result can be obtained, but the number of accumulations increases (2N or 4N), leading to increased power consumption

Engineering Contradiction:

Improvecorrelation result accuracyVSAvoidpower consumption

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent segments the QPSK correlation computation into distinct in-phase (I) and quadrature (Q) component processing paths. By separating the correlation computation into independent I and Q components, each processed through dedicated correlation units, the system avoids the need for complex combined processing while maintaining accurate correlation results. This segmentation reduces the accumulation count from 2N or 4N to N by eliminating redundant computations between components.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS12224891B2Method and apparatus for performing efficient correlation computation between data sequence and both of in-phase code sequence and quadrature code sequence

Publication Date: 2025.02.11 MEDIATEK INC

AI summary

A correlation computation method includes: performing, by a grouping circuit, a grouping operation upon a data sequence according to an in-phase code sequence and a quadrature code sequence, wherein the data sequence is derived from a quadrature phase shift keying (QPSK) modulated signal; performing at least one accumulation operation upon data samples categorized into at least one data sample group by the grouping operation, to generate at least one accumulation result; and deriving a correlation value between the data sequence and both of the in-phase code sequence and the quadrature code sequence from the at least one accumulation result.