• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.31 no.8A
• /
• pp.784-789
• /
• 2006

In this paper, we propose a bitwise information decomposition algorithm for an M-PSK signal based on the Max-Log-MAP algorithm. In order to obtain the algorithm, we use a coordinate transformation from M-PSK to M-PAM signal space. Using the proposed algorithm, we analyze the performance of a Turbo iterative decoding method. The proposed algorithm can be applicable not only for a communication with PSK and iterative decoding method but for adaptive modulation and coding system.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.5 no.4
• /
• pp.684-691
• /
• 2001

In this paper, the BER performance of OFDM/M-ary PSK systems is analyzed with considering carrier-frequency offset and TCM technique, which encodes and modulations simultaneously, is adopted to OFDWM-ary PSK systems for compensation of performance degradation according to carrier-frequency offset. As a result of analysis, the error performance of OFDM/M-ary PSK systems is degraded as the frequency offset is increased. And the frequency offset should be below 0.025 in order to achieve $BER= 10^{-3}$ with $E_b/N_o$ of 10 dB. Especially, when the TCM technique is adopted to OFDM/M-ary PSK systems, the performance improvement of about 4 dB is obtained in terms of $E_b/N_o$.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.65 no.12
• /
• pp.2177-2182
• /
• 2016

Using the existing exact but quite complicated symbol error rate (SER) expressions for M-ary phase shift keying (M-PSK) and M-ary differential phase shift keying (M-DPSK), we derive effective and concise closed-form asymptotic SER formulas especially in Rician-Nakagami fading channels. The derived formulas can be utilized to efficiently verify the achievable error rate performances of M-PSK and M-DPSK systems for the Rician-Nakagami fading environments. In addition, by exploiting the modulation gains directly obtained from the asymptotic SER formulas, we also theoretically demonstrate that M-DPSK suffers an asymptotic SER performance loss of 3.01dB with respect to M-PSK for a given M in Rician-Nakagami fading channels at high signal-to-noise ratio (SNR).

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.31 no.3C
• /
• pp.237-244
• /
• 2006

I/Q phase unbalance caused by non-ideal circuit components is inevitable physical phenomenons and leads to performance degradation when we implement a practical coherent M-ary phase shift keying(M-PSK) demodulator. In this paper, we present an exact and general expression involving two-dimensional Gaussian Q-functions for the bit error rate(BER) of uniform M-PSK with I/Q phase unbalance over an additive white Gaussian noise(AWGN) channel. First we derive a BER expression for the k-th bit of 8, 16-PSK signal constellations when Gray code bit mapping is employed. Then, from the derived k-th bit BER expression, we present the exact and general average BER expression for M-PSK with I/Q phase unbalance. This result can readily be applied to numerical evaluation for various cases of practical interest in an I/Q unbalanced M-PSK system, because the one- and two-dimensional Gaussian Q-functions can be easily and directly computed using commonly available mathematical software tools.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.5 no.5
• /
• pp.908-915
• /
• 2001

In this paper, it is analyzed theoretically that the performance degradation, caused by carrier frequency offset, in an OFDM/M-ary PSK system. Then, when Turbo coding is adopted to an OFDM/M-ary PSK system, the degree of performance enhancement is evaluated. Finally, the maximum frequency offset is calculated to satisfy the BER performance required in a Turbo coded OFDM/M-ary PSK system. As results of analysis, it is shown that the more the number of M-ary is, the worse the BER performance is. Moreover, 7dB, 9dB, and 17dB of $E_b/N_o$ are required in QPSK, 8PSK and 16PSK systems, respectively in order to satisfy the error performance, $BER=10^{-3}$ for voice communication. If $E_b/N_o$ are 10㏈ and 15㏈, the frequency offset should be below 0.05 and 0.075, respectively, for voice communication. When Turbo coding is adopted to an OFDM/M-ary PSK system, the less the number of M-ary is, the greater the performance enhancement of Turbo coding is. If the number of a M-ary system of the system is below 16, it is found that required $E_b/N_o$ is about 8dB to satisfy $BER=10^{-5}$ Moreover, in the system the Turbo coding scheme, voice communication is available with greatly low$E_b/N_o$, and 8dB of $E_b/N_o$ is enough for data communication regardless of the permission range of frequency offset.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.7 no.2
• /
• pp.117-127
• /
• 1996

In this paper, we present the bit error performances of 4PSK and 8PSK signal transmission schemes using Maximal Ratio Combining diversity reception for m-distribution and Rician fading channels. The suitability of modeling a Rician fading environment by a properly chosen m-distribution model is examined. Using the error performance of the derived equation has been evaluated and shown in figures as a function of fading index (m), Rician factor (K), diversity branches number (L) and E($E_b/N_o$). It is found that MRC (Maximal Ratio Combining) diversity technique is very efficient for reducing the effects of fading, And then, diversity benifit much large as depth of fading becomes deeper but more decreases as many diversity branchs. Also the results show that the error performance corresponds as much as fading becomes weak and increases with the number diversty branches.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
• /
• v.4 no.1
• /
• pp.20-27
• /
• 1993

In this paper, a model of TCM / M-PSK with set partitioning and a model of the combined M-ary PSK system with pragmatic coding for digital radio communication are realized. The equations of error probability for TCM / M-PSK system and the combined M-ary PSK system with pragmatic coding are derived on the conditions of the Rayleigh fading with the AWGN. It is found that the combined M-ary PSK systemwith pragmatic coding in the AWGN channel can not be applied to the fading channel since uncoded bits cause parallel:parallel paths in the trellis diagram to degrade the performance of the system. However, the use of pragmatic coding in the AWGN channel could simplify the given system since single convolutional encoder / decoder is required.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.19 no.4
• /
• pp.649-659
• /
• 1994

The channel capacity of fadingchannel becomes less than that of Gaussian noise channel. Moreover, the channel capacity of system with modulated signal is expected to be much less than that of system with nonmodulated signal. It is very difficult to evaluate the capacity in fading channel with modulated signal. The channel capacity for M-ary PSK signal has already been derived in Gaussian noise channel but it is very complicate form composed of complex integral formula. In this paper, we have derived the simple form of channel capacity with M-ary PSK signal by using the average symbol error rate. And we also evaluate the capacity in Rician and m-distribution fading channels as well as Gaussian noise channel. We have verified that the channel capacity obtained are almost the same as in other literature. As a results, we show that the channel capacity of M-art PSK signal increases to converge to the number of bits per symbol (log M) as signal to-noise power ratio increases.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.31A no.2
• /
• pp.1-8
• /
• 1994

In this paper, a model of trellis-coded M-ary PSK (TCM/M-PSK) for digital land mobile communication is realized. Bit error rate(BER) of TCM/M-PSK is calculated theoretically in time selective fading environment due to Doppler spread in the presence of AWGN. cochannel interference. These analyses are employed the receiver with post detection diversity and the direct sequence to improve the BER performance of TCM-MPSK system. It is shown that the CNR required by the diversity reception and the direct sequece(process gain=20dB) TCM-4PSK system is reduced to about 25 dB.

• Journal of Navigation and Port Research
• /
• v.29 no.3 s.99
• /
• pp.245-250
• /
• 2005

In this paper, considering PAR of transmitter which is pointed out OFDM system's problem, we designed Coded OFDM (COFDM) system and estimated BER and SNR using PAR reduction method In order to evaluate performance, we compared M-ary PSK (M-ary Phase Shift Keying) with M-ary QAM (M-ary Quadrature Amplitude Modulation). In result, performance of 16-PSK and 16-QAM came to good Moreover, 16-QAM showed better performance of about 2 dB in 10-3 error probability and performance of about 5 dB in Peak power clipping than that of 16-PSK.