• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.2
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• pp.252-258
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• 2000

In this paper, we improve error performance for BPSK and QPSK when the carrier recovery signal is not perfect in the multipath Rician fading channel based on DS-CDMA system. In the case, we use the MRC(Maximal Ratio Combining) diversity and convolutional coding technique in order to overcome this carrier phase error and Rician fading. With results of analysis, we know that the appropriate use of MRC diversity and convolutional code reduced considerably performance degradation due to phase error.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1312-1320
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• 2008

In this paper, we analyzed the error rate performance of convolution coded 16 QAM signal with Optimum Threshold Detection with maximum ratio combining diversity in Rician Fading Environments. The performance of 16-QAM signal with CTD (conventional threshold detection) which employs convolution coding technique was analyzed and the performance improvement of convolution coded 16-QAM signal with OTD (optimum threshold detection) which is varied according to fading parameter "K" and AWGN in Rician Fading channel was simulated. As a result of analysis, it was shown the effect of performance improvement to overcome the environment of mobile radio data communication channel.

• Journal of Digital Contents Society
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• v.5 no.1
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• pp.28-34
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• 2004

In this paper, we have analyzed the block error probability of orthogonal multicarrier 16 QAM signal in a frequency selective Rician fading environment. The block error probability is evaluated with several parameters such as normalized propagation delay $(\gamma/T_S),$, bit energy to noise power ratio $(E_b/N_0),$ and desired signal to undesired signal power ratio (DUR) in fast fading and slow fading channels. In the fast fading channel, The result shows that the block error probability rather in the fast fading channel achieves better performance than in the slow fading channel, when the error correction capability is one or two.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.4
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• pp.34-40
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• 2012

In wireless communication system, fading is an unavoidable problem. Hence, errors in form of BER are introduced with the transmitted signal. It is necessary to recognize the behavior of these errors in different fading channels. To obtain the mathematical solution for the average bit error rate(BER) of coherent MPSK, some techniques are presented. In this paper, the impact of diversity is also analyzed over slow and flat Rician fading channel. In here, the value of modulation index, M is varied and the effects of its variation are also depicted. So, these performance curves with different diversity values and fading parameter are useful to design and evaluate the radio channel for faithful communication system.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.7 no.1
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• pp.61-70
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• 1996

M-ary differential phase shift keying(DPSK)is a bandwidth efficient digital modulation technique and recently has attracted increased attention in mobile satellite communication application where the available radio bandwidth is limited. Coherent detection offers good BER performance in AWGN channel. However, it requires long acquisition times in fading environment. In this paper, we analyze the BER performance of M-ary DPSK signal using the Multiple Differ- ential Feedback Detection(MDFD) technique in Rician fading and shadowed Rician fading channel. MDFD is an efficient scheme to decrease the performance gap between differential and coherent reception by increasing the complexity of the conventional differential receiver to some extent. Compared to the multiple symbol maximum likelihood detection technique, the multiple differential feedback detection technique has a much simpler structure for hardware implementation. Espe- cially, this technique has application to land mobile satellite channel which can vary in time and space between AWGN and rapidly fading channel.

• Journal of information and communication convergence engineering
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• v.2 no.4
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• pp.224-227
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• 2004

The purpose of this paper is to theoretically analysis of performance of MRC diversity for detection of M-ary signals on the Rician fading channels. To do it, the difference between the approximation to bit error probability and the exact bit error rate (BER) in evaluating the performance of MPSK signals is investigated by numerical analyses. In addition, the performance evaluation of MDPSK signals in the independent branch diversity is performed by an integral-form expression in case of when MDPSK signal in MRC system is experiencing the Rician fading.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.2
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• pp.68-74
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• 2010

In this paper, we analyze and simulate the channel capacity of a spread spectrum watermarking (SSW) technique in wireless fading channel to apply ITS system. Channel capacity analysis causing minimum effect to existing system is required necessary to apply SSW technique. We derive the channel capacity as a closed-form approximation formula in Rayleigh and Rician fading channel model. The numerical results are demonstrated and good approximated results are reported.

• The Journal of the Acoustical Society of Korea
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• v.16 no.3E
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• pp.24-31
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• 1997

A mobile propagation characteristics for wideband DS-SS (Direct Sequence-Spectrum) signal is presented. Existing narrowband model is extended for the wideband pulse with an arbitrary shape. The received DS-SS signal in the frequency domain is the transfer function of the propagation channel weighted by the inverse Fourier transform. In this proposed method, received signal spectral density, instantaneous waveform, and Doppler spectrum of DS-SS signal via either Rayleigh of Rician channel can be obtained easily. Simulation results match well with both simulated theoretical fading statistics and classical theory. As expected, the extraction of chip timing in Rician fading shown to be more tractable than Rayleigh fading.

• Proceedings of the IEEK Conference
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• 2002.07c
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• pp.1451-1454
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• 2002

In recent years, there are growing concerns about land mobile satellite (LMS) communication systems and mobile stratospheric communication systems (SCS) for the purpose of service upgrade of personal and mobile communications in near future. It is important to possess accurate channel model for prediction of the above system performance. Thus, in this paper, we evaluate the bit error rates of a coded BPSK system based on realistic channel model which can be applied to stratospheric communication systems. The channel data was made by fitting the parameters of probability distribution model to measured data. This approach was proposed by Corraza〔1〕and modified by You〔2〕. And also the effects of channel codings on the system performance are analyzed. As results, we can get the performance curve characteristics on realistic Rician log-normal fading channels with various communication environments.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.05a
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• pp.195-198
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• 2000

This paper have been analyzed performance of DS-CDMA/QPSK system in short range IVC, and evaluated packet uu rate(PER) in an On-Ray Rician channel model suitable for platoon driving of AVHS that 60GHz millimeter wave is very powerful to MP(multipath-wave). We analyzed probability characteristic of system as variation of Rician factor and user number in One-Ray Rician fading environment and evaluated packet error rate(PER) according to inter-vehicle distance when the BCH channel coding(255,247,1) and diversity schemes is adopted.