Taeung Yoon

AltBOC and CBOC Correlation Functions for GNSS Signal Synchronization

Binary offset carrier (BOC) signal synchronization is based on the correlation between the received and locally generated BOC signals. Thus, the multiple side-peaks in BOC autocorrelation are one of the main error sources in synchronizing BOC signals. Recently, new correlation functions with no side-peak were proposed for sine and cosine phased BOC signal synchronization, respectively, by the authors [3]. In this paper, we propose new correlation functions with no side-peak for alternative BOC (AltBOC) and composite BOC (CBOC) signals by using the similar approach to the previous work.

Symbol error rate of the dm-mpsk under the influence of jamming signals

Focusing on the performance of the chirp spread spectrum (CSS) communication system under the influence of jamming, we analytically derive the symbol error rate (SER) for the direct modulation CSS system with M-ary phase shift keying in the presence of broadband and tone jamming signals. From numerical results, it is confirmed that the analytic result agrees closely with the empirical SER.

Performance Analysis of a CSS System with M-ary PSK in the Presence of Jamming Signals

Due to its anti-jamming capability, chirp spread spectrum (CSS) technique has attracted much attention in the area of wireless communications. However, there has been little rigorous analysis for the performance of the CSS communication system in the presence of jamming signals. In this paper, we present analytic results on the performance of a CSS system: symbol error rate (SER) expressions are derived for a CSS M-ary phase shift keying (MPSK) system in the presence of broadband and tone jamming signals, respectively. The numerical results show that the empirical SER closely agrees with the analytic result.

Performance Analysis of an Overlap-Based CSS System

Overlap is one of the techniques for increasing bit rate in chirp spread spectrum (CSS). Although more overlaps can offer higher data throughput, more intersymbol interference (ISI) occurs, resulting in serious bit error rate (BER) performance degradation. In this paper, we analyze the influence of the overlap on CSS systems and express the maximum number of overlapped symbols that does not incur the ISI, in terms of the chirp bandwidth and chirp duration. The analysis results are verified by BER performance simulation of direct modulation differential phase shift keying (DM-DPSK) that is a typical modulation method used in CSS.

New schemes of carrier frequency offset estimation for DVB systems

In this paper, new integer frequency offset estimation schemes are proposed for orthogonal frequency division multiplexing (OFDM)-based digital video broadcasting (DVB) systems. Several pilot-aided integer frequency offset estimation schemes have been proposed for OFDM-based DVB systems. However, the conventional schemes use only some parts of pilot combinations. Thus, in this paper, we propose new integer frequency offset estimation schemes exploiting the additional information of pilot combinations. The simulation results show that the proposed schemes outperform the conventional schemes in terms of the probability of carrier frequency offset estimation failure.

Enhanced Multiple-Shift Scheme for Rapid Code Acquisition in Optical CDMA Systems

In this paper, we propose a novel code acquisition scheme called enhanced multiple-shift (EMS) for optical code division multiple access (CDMA) systems. By using multiple thresholds, the proposed EMS scheme provides a shorter mean acquisition time (MAT) than that of the conventional mutiple-shift (MS) scheme. The simulation results demonstrate that the MAT of EMS scheme is shorter than that of MS scheme in both single-user and multi-user environments.