• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.10
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• pp.1161-1168
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• 2010

The FHSS(Frequency Hopping Spread Spectrum), in which a transmitter changes its carrier frequency according to a certain hopping pattern, is widely used in the military communication system, since it is highly resistant to deliberate Jamming. However, the difference of BER performance of satellite communication system which using the different modulation scheme and Jamming model was not studied. Thus, in this paper, we consider PBNJ(Partial-Band Noise Jamming) and WPBJ(Worst case Partial-Band noise Jamming) as Jamming models, and evaluate BER(Bit Error Rate) performances of NC-MFSK(Non-Coherent M-ary Frequency-Shift Keying), SDPSK(Symmetric Differential Phase-Shift Keying), and GMSK(Gaussian filtered Minimum-Shift Keying) modulation schemes. Based on the results, we suggest the best transmission method for each condition.

• Journal of information and communication convergence engineering
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• v.2 no.3
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• pp.145-148
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• 2004

The performances of M-ary signals using L-branch maximum ratio combining (MRC) diversity reception in correlated Nakagami fading channels are derived theoretically. The coherent reception of M-ary differential phase shift keying (MDPSK), phase shift keying (MPSK), and quadrature amplitude modulation (MQAM) is considered. It is assumed that the fading parameters in each diversity branch are identical. The general formula for evaluating symbol error rate (SER) of M-ary signals in the independent branch diversity system is presented using the integral-form expressions.

• Journal of Navigation and Port Research
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• v.35 no.10
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• pp.811-816
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• 2011

In this paper, we analysis to consider the performance of PSPM (Phase Shift Pulse-position Modulation), the one of the low power communication technique, in near-field underwater sound channel by sea trial. PSPM is a QPSK(Quadrature Phase Shift Keying) modulation combined with PPM(Pulse Position Modulation) for low power communication in WBAN(Wireless Body Area Network). It is known that the bandwidth efficiency of PSPM is lower than conventional PSK but the power efficiency increases. In this paper, we will analyze the BER performance of PSPM using data acquired from the sea trials. The BER of QPSK was $6.04{\times}10^{-2}$, PSPM was $3.5{\times}10^{-1}$. Also, PSNR of QPSK was 9.37 dB and in case of PSPM was 9.11 dB.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.6 s.360
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• pp.18-23
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• 2007

In this Paper, we consider multiple input multiple output Feher-patented quadrature phase shift keying (MIMO-FQPSK) system supporting high spectral efficiency and throughput. Based on the fact that the complex baseband signal sampled at every bit duration has only eight phase values and its signal can be considered as 8-phase-shift keying signal, FQPSK demodulation with maximum likelihood sequence estimation(MLSE) is considered and it is extended to MIMO system. The performance of MIMO-FQPSK receiver is analyzed by computer simulation and by considering the union upper bounds for zrero forcing detection and minimum mean square error detection.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.6B
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• pp.689-696
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• 2011

In this paper, we propose the result of PSSK(Phase Silence Shift Keying) modulation scheme that is mixed PSK(Phase Shift Keying) modulation and PPM(Pulse Position Modulation) method. The performance of underwater communication systems are influenced underwater channel characteristics. In particular, delay spread can make ISI(Inter Symbol Interference) because of reverberation and multi path. It degrade the performance of the communication system. Also underwater sensor networks consider about power efficient due to the particularities of their operating environment. PSSK modulation method transmit two orthogonal symbol and using silence period in a period so it can reduce the power. Increasing the distance of between modulation symbols, to enhance the performance of BER(Bit Error Rate) as well as to improve power efficient. The result of sea trial, QPSK modulation BER is $3.19{\times}10^{-1}$ and PSSK modulation BER is $2.89{\times}10^{-1}$.

• The Journal of the Acoustical Society of Korea
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• v.41 no.2
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• pp.159-165
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• 2022

In this paper, a frame synchronization structure for the Binary Phase Shift Keying (BPSK) modulation method in underwater acoustic communication was proposed. The proposed frame synchronization structure is largely divided into two. First, the approximate position and frequency offset of the frame are obtained by non-coherent correlation and sliding Fast Fourier Transform (FFT) method. Second, after compensating for the frequency error to the received signal, the exact position of the frame is obtained by coherent correlation method. Maritime experiments were conducted to confirm the performance of the 2-STEP frame synchronization structure. It was showed that the limitations of the non-coherent correlation and sliding FFT method can be verified when the power of the received signal was greatly reduced due to the channel characteristics. As a result, stable frame synchronization could be obtained by compensating for the frequency error and then using the coherent correlation method.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.3 s.94
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• pp.286-292
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• 2005

We design and analyze the bit interleaved coded modulation(BICM) for noncoherent N-symbol continuous phase frequency shift keying(CPFSK) on the interleaved Rayleigh fading channel. In this paper, we use the equivalent normalized squared distance(ENSD) of noncoherent N-symbol CPFSK to design and analyze the BICM system. Specially, we design the BICM system for noncoherent 2-symbol 4-ary CPFSK, and analyze the performance of the system by using the ENSD. Simulation results are also provided to verify the theoretical performance analysis.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.6
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• pp.140-145
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• 2017

A channel is very sever in an underwater acoustic communication. Therefore, a modulation method with high spectrum efficiency is needed in an underwater acoustic communication. PSK(phase shift keying) for transmitting 1 bit or 2 bits is robust to noise, but sensitive to noise about more than 3 bits. CPFSK error performance for transmitting 1 bit or 2 bits is similar to that of PSK and CPFSK decreases high frequency components in modulation signal. In the paper, I analyze the performance of trellis coded 4-CPFSK modulation.

• ETRI Journal
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• v.26 no.5
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• pp.501-504
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• 2004

This paper presents a simple gain/phase blind compensation algorithm with an automatic gain control (AGC) function for the adoption of the AGC function and compensation for gain/phase imbalances in quadrature phase shift keying (QPSK) direct conversion receivers (DCRs). The AGC function is interactively operated with the compensation algorithm for gain/phase imbalances. By detecting the gain sum and difference values between the I-channel and Q-channel, the combined AGC and gain imbalance compensation algorithm provides a simpler DCR architecture.

• Proceedings of the KIEE Conference
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• 2008.10b
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• pp.119-120
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• 2008

본 논문에서는 ECMA 표준에 기반한 multi-gigabit packet 수신기를 위한 프레임 검출 방안을 제안한다. ECMA 표준은 60 GHz 대역에서 multi-gigabit 전송률을 달성하기 위하여 버스트 (burst) 송수신 방식을 사용하며 프리앰볼 (preamble)과 데이터 (data)로 이루어진 프레임 (frame)을 통하여 데이터 송수신이 이루어진다. 본 논문에서는 ECMA 표준 중 DBPSK (Differential Binary Phase Shift Keying)와 DQPSK (Differential Quadrature Phase Shift Keying) 그리고 OOK (On-Off Keying) 변조 방식을 지원하는 multi-gigabit 송수신 시스템을 위한 프레임 검출기를 설계하였다. 설계된 프레임 검출기는 동일한 구조 및 동작 방식을 통하여 고려한 모든 변조 방식들을 지원할 수 있을 뿐만 아니라 하드웨어 구현 복잡도가 낮은 장점을 지닌다.