Keunhong Chae

Unambiguous BOC Signal Tracking Based on Partial Correlations

This paper proposes a novel unambiguous correlation function for sine-phased binary offset carrier (BOC) tracking. Modeling a BOC signal pulse as a sum of multiple rectangular pulses, correlating the multiple rectangular pulses with the received BOC signal, and combining the correlations, we construct an unambiguous correlation function with only a single main-peak. The proposed correlation function is confirmed from numerical results to provide an improved tracking performance over the conventional correlation functions.

A novel unambiguous composite binary offset carrier(6,1,1/11) tracking based on partial correlations

An unambiguous tracking scheme is proposed for CBOC(6,1,1/11) signal.The proposed scheme combines the partial correlations in a specially designed way.The autocorrelation side-peaks are completely removed by the proposed scheme.Better TESD and MEE performances are achieved over those of the conventional schemes. This paper proposes a novel unambiguous correlation function for composite binary offset carrier (CBOC) signal tracking based on partial correlations. In the proposed scheme, first, we partition sub-carriers of the CBOC signal into partial sub-carriers, and subsequently, we obtain partial correlations by correlating the partial sub-carriers with the received CBOC signal. Finally, a novel unambiguous correlation function with no side-peak is constructed by combining the partial correlations in a specially designed way. Unlike the conventional schemes, the proposed scheme does not require any auxiliary signal and from numerical results, it is found to offer a better tracking performance than those of the conventional schemes in terms of the tracking error standard deviation (TESD) and multipath error envelope (MEE).

An unambiguous correlation function for generic sine-phased binary offset carrier signal tracking

Ambiguity in tracking is the major problem in binary offset carrier signal tracking.The ambiguity in tracking is caused by the BOC correlation side-peaks.A correlation function with no side-peaks is proposed for generic sine-phased BOC.The correlation function removes the ambiguity and improves the tracking performance. This paper proposes an unambiguous correlation function applicable to generic sine-phased binary offset carrier (BOC) signal tracking. In the proposed scheme, first, we view the BOC sub-carrier pulse as a sum of multiple rectangular pulses. Then, we obtain partial correlation functions by correlating the multiple rectangular pulses with the received signal, and subsequently, construct two symmetric correlation functions by combining the partial correlation functions in a specialized way. Finally, we generate an unambiguous correlation function by combining the two symmetric correlation functions. The proposed correlation function has a sharper main-peak, and consequently, provides a better tracking performance than those of the conventional correlation functions in terms of the tracking error standard deviation (TESD).

An improved direct acquisition scheme for rapid P code acquisition

To resolve the problem of ambiguity caused by the folding used widely in direct acquisition (DA) of the precision code (P code) in the global positioning system (GPS), a two-step DA scheme is proposed based on the zero-padding and local P code modification. The coarse acquisition is achieved in the first step based on the folding, which allows us to maintain the advantage of the folding, and the zero padding with a local code modification performs the fine acquisition in the second step, removing the problem of ambiguity. In numerical results, the proposed DA scheme is found to provide a shorter mean acquisition time over the conventional DA schemes in most of the jamming-to-signal ratio (JSR) range of practical interest.

Unambiguous Tracking Technique Based on Sub-Carrier Pulse Grouping for TMBOC-Modulated Signals in GPS

Based on grouping the pulses that compose the sub-carrier of the time-multiplexed binary offset carrier (TMBOC), we present an unambiguous correlation function that has no side-peaks causing the ambiguity in the TMBOC signal tracking, and also, that has a higher degree of the sharpness of the main-peak (DSM) over those of the conventional unambiguous correlation functions. Splitting the pulses composing the TMBOC sub-carrier into 12 groups, and, subsequently, forming the 12 group correlations corresponding to the 12 groups, we investigate the contribution of each of the 12 group correlations to the side peaks and main peak of the TMBOC autocorrelation function. Then, we propose a combining method of the 12 group correlations based on the investigation to remove the side peaks while improving the DSM. Numerical results demonstrate that the proposed unambiguous correlation function not only has no side-peaks, but also has a higher DSM, and, consequently, has a better tracking error performance than those of the conventional unambiguous correlation functions.