• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.29 no.6A
• /
• pp.683-689
• /
• 2004

The power and bandwidth efficient constant-envelope BPSK (CE-BPSK) modulation is proposed. The CE-BPSK signal is realized specifying the phase transition characteristics for the conventional low pass filtered BPSK signal. Since the CE-BPSK signal has constant envelope and modified waveform, the CE-BPSK signal has better power and bandwidth efficiency compared to the conventional BPSK signal while the CE-BPSK signal is backward compatible to the conventional BPSK signal. It is also shown that the bit error rate performance of the CE-BPSK signal is the same as that of the conventional BPSK signal.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.41 no.11
• /
• pp.1380-1386
• /
• 2016

In this paper, we propose and evaluate OFDM(Orthogonal Frequency Division Multiplexing)-SSB(Singe Side Band) for improving spectral efficiency. The proposed system is based on OFDM system using DCT(Discrete Cosine Transform) and DHT(Discrete Hilbert Transform) for SSB modulation, this proposed system transmit a BPSK modulation signal through a single sideband and BPSK modulation signal through the other single sideband. In other words, we design and evaluate the proposed system which transmit two BPSK signal through each other single sideband. Also each BPSK BER performance is similar with theoretical BPSK BER performance. the proposed system transmits BPSK signal using half of spectrum of conventional OFDM system or transmit two BPSK signal in same time.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.19 no.8
• /
• pp.1518-1527
• /
• 1994

An algorithm for BPSK demodulation of which channel is an electric distribution line is developed, and realized in this paper. To realize the BPSK demodulation by microprocessor, BPSK signal that is received through the distribution line must be converted to digital signal. A hardware which converts BPSK signal to digital one has been designed in this paper, and an algorithm for BPSK demoduation of which channel is distribution line has been also developed in algorithm for BPSK demoduation of which channel is distribution line has been also developed in this paper by paying the attention to the fact that a modulated point appears up and down according to the rising edge and falling edge of the modulated binary signal if the carrier frequency is even times to the modulated binary signal, and by paying the attention to the fact that the signal duration or modulated point is twice of the other point. The microprocessor demodulation system with the algorithm has been realized. The system proved to have 0.02%(or less) bit error rate in real BPSK demodulation.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.4 no.1
• /
• pp.201-209
• /
• 2000

In this paper, the bit error rate (BER) performance of Multicode DS/CDMA-BPSK communication system is investigated in the presence of multi user interference and Nakagami fading channel environments. The DS/CDMA-BPSK communication system adopts multicode technique to enhance the data transmission rate. Using the calculated BER performance, BER figures of Multicode DS/CDMA-BPSK communication system are shown to discuss the effect of the number of multi user interference, Nakagami fading index, and data transmission rate. From the results, the transmission rate of DS/CDMA-BPSK signal improve by adopting Multicode technique. And we know that the major parameter of BER performance degradation in Multicode DS/CDMA system is the effect of multi user interference than the fading depth.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.36 no.10B
• /
• pp.1246-1251
• /
• 2011

In this paper, BPSK-OFDM-based LED communication systems are applied to watermarking techniques, were studied on how to transfer the additional information data with at the same time as the transfer of LED communication data. For watermarking kasami code was used as spreading codes, and spread additional data is controlled by small signal level to be BPSK-OFDM does not affect the optical signal. BPSK-OFDM is added to an optical signal is transmitted. The performance of the spreading code as a kasami code is autocorrelation of the noise-free environment, under the noise environment was confirmed by autocorrelation. BPSK-OFDM-based LED communication system has been applied proposed technique throughout the simulation in analyzed to BER of BPSK-OFDM DER performance and watermark signal level according to signal size level of data. That was availability confirmed for watermarking data transmit techniques data as being analysis detection performance of watermarking information using LED communication according to the code.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.11 no.3
• /
• pp.484-491
• /
• 2000

It is necessary to apply SSB modulation method with high bandwidth efficiency to the DS-CDMA mobile communication systems in order to accommodate the increasing number of voice users as well as the broad band and high data rate service in the future. Even though the bandwidth efficiency increases if SSB modulation is applied to BPSK-DS/CDMA, its performance gets degraded because of the increased multiple access interference. Therefore for eliminating the increased multiple access interference, the SSB/BPSK-DS/CDMA with successive interference canceller(SIC) is proposed and its performance and capacity are analyzed. With the limited system bandwidth, it is shown that the SSB/BPSK-DS/CDMA with SIC can accommodate more capacity than the conventional BPSK-DS/CDMA with SIC.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.21 no.4
• /
• pp.1019-1026
• /
• 1996

A modulation type classifier based on statistical moments has been successfully employed to classify PSK signals. Previously, developed Classifiers were analyzed in AWGN channel only. In this paper, a moments-based modulation type classifier to classify BPSK and QPSK signals over Rayleigh fading channel is proposed and analyzed. The moments of received signal are evaluated with the exact distribution of the received signal and a moments-based classifier is proposed. The performance evaluation of the proposed classifier in terms of the misclassification probability for BPSK and QPSK is investigated under Rayleigh fading environment.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.16 no.1
• /
• pp.81-88
• /
• 2013

This paper describes the fundamentals, design, realization and test results of a BPSK(Bi Phase Shift Keying) transceiver for the direction finding proximity fuze sensor for anti-aircrafts or air missiles. The BPSK transceiver for the direction finding fuze sensor has been designed to detect a moving target by Doppler signal processing with the code correlation method and to distinguish direction by comparing received powers of each Doppler signal from adjacent three receiving antennas. The electrical and ESS(Environmental Stress Screening) tests of the BPSK transceiver showed satisfactory results and target detection and direction finding performances proved to be successful through dynamic operation tests by 155 mm gun firing.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.11 no.1
• /
• pp.64-72
• /
• 1986

The error rate equation fo DS-BPSK(Direct Sequence Binary Phase Shift Keying) signal transmitted through the nonlinear satellite transponder has been derived in the cochannel interference and downlink Gaussian noise environment. The input to the satellite transponder is the superposition of DS-BPSK signal with one interfere which is a cochannel wide-band PN signal. The error rate performance of DS-BPSK system has been evaluated and shown in figures in terms of carrier to interference power ratio(CIR), downlink signal to noise power ratio(downlink SNR) and process gain. In the analysis, it has been shown that the use of a hard limiter in DS-BPSK satellite system leads to the generation of narrow-band intermodulation products which is independent of the process gain. Also it is known that the error rate performance can be improved in the low levels (below 10dB) of CIR as the CIR increase. As the process gain varies from 10 to 100 the curve gives the about 10 dB gain in downlink SNR to maintain a fixed error rate.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.41 no.11
• /
• pp.25-32
• /
• 2004

In this paper, we first analysed the ability of DSSS resistance against noises, which are main interferences to the four types in power line communications. Based on the characteristic of these noises, we made a noise source of power line which is similar with the result measured, in practice. We simulated and analysed the BER performance of BPSK with DSSS over this noise model and one without the DSSS, for comparison. Result showed that the BPSK with DSSS system has improved by 8 dB, as compared to those without the DSSS, as against power line noises.