Method for generating unambiguous correlation function for CBOC (6,1,1/11) signal based on partial correlation functions, apparatus for tracking CBOC signals and satellite navigation signal receiver system

Patent metadata

Field	Value
Publication number	US-9857477-B2
Application number	US-201414534289-A
Country	US
Kind code	B2
Filing date	Nov 6, 2014
Priority date	Nov 7, 2013
Publication date	Jan 2, 2018
Grant date	Jan 2, 2018

Abstract

A method of generating a correlation function for a CBOC(6,1,1/11) signal according to the present invention includes generating a delayed signal delayed based on a phase delay, with respect to a signal pulse train of a CBOC(6,1,1/11)-modulated received signal, generating first to twelfth partial correlation functions by performing an autocorrelation operation of the received signal and the delayed signal with respect to a total time, generating a basic intermediate correlation function by performing an elimination operation on sixth and seventh partial correlation functions, acquiring first to fifth and eighth to twelfth additional intermediate correlation functions by performing an elimination operation on each of partial correlation functions, excluding the sixth and seventh partial correlation functions from the first to twelfth partial correlation functions, and a basic intermediate correlation function, and acquiring the main correlation function by simply summing the basic intermediate correlation function and the first to fifth and eighth to twelfth additional intermediate correlation functions.

First claim

What is claimed is:

1. A delay lock loop (DLL), comprising:
a local signal generation circuit configured to generate an early and late delayed signal pair B(t+τ+Δ/2) and B(t+τ−Δ/2), respectively, based on a phase delay τ and a delay value difference Δ provided by a numerical control oscillator (NCO), with respect to a signal pulse train of a CBOC(6,1,1/11)-modulated received signal B(t), wherein the CBOC is a composite binary offset carrier;
early and late autocorrelation circuits configured to generate first to twelfth early partial correlation functions {S m (τ+Δ/2)} m=0 11 of the CBOC(6,1,1/11)-modulated received signal B(t) and first to twelfth late partial correlation functions {S m (τ−Δ/2)} m=0 11 of the CBOC(6,1,1/11)-modulated received signal B(t) by performing an autocorrelation operation of early and late mixing signal pairs with respect to a total time T (0≦t≦T), wherein S m is an m-th partial correlation function;
early and late basic intermediate correlation function generation circuits configured to generate an early basic intermediate correlation function R a (τ+Δ/2) by performing an elimination operation on sixth and seventh early partial correlation functions S 5 (τ+Δ/2) and S 6 (τ+Δ/2) of the CBOC(6,1,1/11)-modulated received signal B(t), and to generate a late basic intermediate correlation function R a (τ−Δ/2) of the CBOC(6,1,1/11)-modulated received signal B(t) by performing an elimination operation on sixth and seventh late partial correlation functions S 5 (τ−Δ/2) and S 6 (τ−Δ/2) of the CBOC(6,1,1/11)-modulated received signal B(t), wherein R a is a basic intermediate correlation function;
an early additional intermediate correlation function generation circuit configured to acquire first to fifth and eighth to twelfth early additional intermediate correlation functions {R m (τ+Δ/2)} m=0,m≠5,6 11 by performing an elimination operation on each of remaining ten early partial correlation functions {S m (τ+Δ/2)} m=0,m≠5,6 11 , excluding the sixth and seventh early partial correlation functions S 5 (τ+Δ/2) and S 6 (τ+Δ/2) from the first to twelfth early partial correlation functions {S m (τ+Δ/2)} m=0 11 , and the early basic intermediate correlation function R a (τ+Δ/2), wherein R m is an additional intermediate correlation function;
a late additional intermediate correlation function generation circuit configured to acquire first to fifth and eighth to twelfth late additional intermediate correlation functions {R m (τ−Δ/2)} m=0,m≠5,6 11 by performing an elimination operation on each of remaining ten late partial correlation functions {S m (τ−Δ/2)} m=0,m≠5,6 11 , excluding the sixth and seventh late partial correlation functions S 5 (τ−Δ/2) and S 6 (τ−Δ/2) from the first to twelfth late partial correlation functions {S m (τ−Δ/2)} m=0 11 , and the late basic intermediate correlation function R a (τ−Δ/2);
early and late combination circuits configured to acquire an early main correlation function R proposed (τ+Δ/2) by summing the early basic intermediate correlation function R a (τ+Δ/2) and the first to fifth and eighth to twelfth early additional intermediate correlation functions {R m (τ+Δ/2)} m=0,m≠5,6 11 , and to acquire a late main correlation function R proposed (τ−Δ/2) by summing the late basic intermediate correlation function R a (τ−Δ/2) and the first to fifth and eighth to twelfth late additional intermediate correlation functions {R m (τ−Δ/2)} m=0,m≠5,6 11 ; and
the NCO configured to determine the phase delay τ for the CBOC(6,1,1/11)-modulated received signal B(t) based on discrimination output of a discrimination function based on values of the early and late main correlation functions, and to output the determined phase delay τ to the local signal generation circuit;
wherein the elimination operation performed on the sixth and seventh early partial correlation functions S 5 (τ+Δ/2) and S 6 (τ+Δ/2), the elimination operation performed on the sixth and the seventh late partial correlation functions S 5 (τ−Δ/2) and S 6 (τ−Δ/2), the elimination operation performed on each of the remaining ten early partial correlation functions {S m (τ+Δ/2)} m=0,m≠5,6 , and the elimination operation performed on each of the remaining ten late partial correlation functions {S m (τ−Δ/2)} m=0,m#5,6 11 , each satisfy a condition |A|+|B|−|A−B|, wherein A and B are real numbers.

2. The DLL of claim 1 , wherein the first to twelfth early partial correlation functions {S m (τ+Δ/2)} m=0 11 and the first to twelfth late partial correlation functions {S m (τ−Δ/2)} m=0 11 are acquired as results of autocorrelation operations based on partial received signals including pulses at respective pulse locations of the CBOC(6,1,1/11)-modulated received signal B(t) in accordance with the following equation:

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Assignees

• Research & Business Found Sungkyunkwan Univ

Inventors

• Yoon Seok Ho
• Chae Keun Hong

Classifications

• H04L27/2278

  using correlation techniques, e.g. for spread spectrum signals · CPC title

• H03L7/087

  using at least two phase detectors or a frequency and phase detector in the loop · CPC title

• G01S19/30 Primary

  code related {(G01S19/246 takes precedence)} · CPC title

• H03L7/185

  using a mixer in the loop (H03L7/187 - H03L7/195 take precedence) · CPC title

• H03L7/093

  using special filtering or amplification characteristics in the loop (H03L7/087 - H03L7/091 take precedence) · CPC title