• Title/Summary/Keyword: BER Performance Improvement

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A Novel Design of CDSK Receiver for Improving the BER Performance (BER 성능 향상을 위해 제안하는 새로운 CDSK 수신기)

  • Lee, Jun-Hyun;Ryu, Heung-Gyoon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.38A no.8
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    • pp.638-643
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    • 2013
  • Chaos communication system has a sensitive characteristic to initial conditions, because completely another signal is generated when initial condition of chaos equation is changed subtly. Also, chaos communication systems have the characteristics of non-periodic, non-predictability, the broadband signal, such as ease of implementation. Due to these characteristics, security of chaos communication system generally is evaluated better than other systems. However, BER(Bit Error Rate) performance is evaluated worse than other digital system, because existing chaos communication system's transmitter and receiver are strong influence by interference signal and noise. So, research to improve the BER performance of the chaotic communication system is performed continuously. In this paper, We will propose a new CDSK(Correlation Delay Shift Keying) receiver for BER performance improvement. After we compare to the performance of existing CDSK receiver and proposed CDSK receiver, BER performance of proposed CDSK receiver evaluate. Also, when using the new CDSK receiver, we evaluate the BER performance according to the spreading factors and find an optimum spreading factor. If chaos communication system use a new CDSK receiver, BER performance is improved than existing CDSK receiver. Also, if spreading factor's value is increased, BER performance is improved, because it is not nearly affected by interference signal and noise.

Performance Analysis of MC DS-CDMA System using Turbo Code in Multipath Rayleigh Fading Channel (다중경로 레일리 페이딩 채널에서 Turbo 부호를 적용한 MC DS-CDMA 시스템의 성능 분석)

  • 박기식
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.5 no.5
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    • pp.902-907
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    • 2001
  • In this paper, we analyzed BER performance of the MC DS-CDMA system and evaluated the degree of performance improvement of the system caused by adopting turbo code recently receiving much attention due to its powerful coding capability. As a result of analysis, it was found that the MC DS-CDMA system without any powerful coding scheme can not serve voice quality $(BER : 10^{-3}$ regardless of the number of users and the value of $(BER : 10^{-3)$ in Rayleigh fading channel. On the other hand, it was found that the MC DS-CDMA system adopting turbo code for performance improvement, shows improved BER performance and can serve voice quality without regard to the number of users and the value of $(BER : 10^{-3)$ in the same channel. For example, when $(BER : 10^{-3)$ is l0dB and the number of users was 10, the MC DS-CDMA system adopting turbo code showed improved BER performance about $5\times10^{-3}$.

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An Improvement of BER Performance for Coded 16-QAM over Mobile Communication Channel by Asymmetric Signal Constellation (비대칭 신호점에 의한 부호화된 16-QAM의 이동 무선 채널에서의 BER 성능 개선에 관한 연구)

  • 김태헌;하덕호
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.8 no.2
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    • pp.197-206
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    • 1997
  • The purpose of this paper is to propose an improvement method of BER for coded 16QAM over Rayleigh fading channel. To overcome the BER degradation due to the fading under mobile communication, we apply trellis coded modulation technique which is efficient to get a coding gain without the expansion of bandwidth. Especially, to minimize the burst error which are the main factor of the BER degradation for mobile communication systems, we apply interleaving/deinterleaving method to the studying system. Also we apply asymmetric signal mapping methods to this TCM scheme. From the computer simulation, BER performance of asymmetric case has achieved about 1 dB improvement of about $10^{-4}$, compared to the traditional symmetric case.

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BER Performance Evaluation of Boss Map According to Delay Time in CDSK Modulation Scheme and Chaos Transceiver (CDSK 변조 방식과 카오스 송수신기의 지연시간에 따른 Boss Map의 BER 성능 평가)

  • Lee, Jun-Hyun;Keum, Hong-Sik;Lee, Dong-Hyung;Ryu, Heung-Gyoon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39A no.7
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    • pp.365-371
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    • 2014
  • Chaos communication system is possible to improve the system security by using chaos signal. Further, it is possible to reduce the possibility of eavesdropping, and have strong characteristics from interference signal and jamming signal. However, BER(Bit Error Rate) performance of chaos system is worse than digital communication system. By this reason, researches in order to improve the BER performance of chaos communication system are being actively studied. In previous studies, we proposed a novel chaos map for BER performance improvement, and called it 'Boss map'. Also, we proposed a novel chaos transceiver for BER performance improvement. However, BER performance is evaluated differently according to delay time in transceiver. Therefore, in order to use Boss map effectively, we should find the optimal delay time in proposed chaos transceiver. In this paper, when Boss map is used, we evaluate BER performance of CDSK(Correlation Delay Shift Keying) system and novel chaos transceiver according to delay time. After evaluation of BER performance according to delay time, we find a delay time that is possible to have best BER performance in CDSK system and novel chaos transceiver.

BER Performance Analysis of Intelligent Reflecting Surface NOMA for Strongest Channel Gain User

  • Kyuhyuk, Chung
    • International Journal of Internet, Broadcasting and Communication
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    • v.15 no.4
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    • pp.84-89
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    • 2023
  • Recently, the sixth generation (6G) networks have become tremendous research topics. Intelligent reflecting surface (IRS) technologies have been envisioned, to increase spectrum and energy efficiency for the fifth generation (5G) mobile networks, towards the sixth generation (6G) communications. In this paper, especially for the strongest channel gain user, we investigate the bit-error rate (BER) of non-orthogonal multiple access (NOMA) systems with intelligent reflecting surface (IRS). First, we derive a BER expression in a closed-form of Q functions. Second, we investigate the BER performance improvement of IRS NOMA systems over NOMA systems versus the power allocation. Moreover, we analyze the BER performance improvement of IRS NOMA systems over NOMA systems versus the number of IRS devices. In results, NOMA equipped with IRS technologies could play an important role in the paradigm shift from 5G mobile networks to 6G mobile networks.

Performance Analysis of Multi-Carrier CDMA System by Multi-User Interference Cancellation Techniques (다중 접속 간섭 제거 기법에 의한 Multi-Carrier CDMA 시스템의 성능 분석)

  • Park, Ki Sik
    • Journal of Advanced Navigation Technology
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    • v.6 no.4
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    • pp.306-311
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    • 2002
  • In this paper, we have proposed the Multi-Carrier (MC) CDMA system by adopting multi-interference cancellation techniques connecting an adaptive array antenna and a CCI canceller in cascade form. And, we have analyzed the BER performance of system in AWGN channel where MUI is a major interference degrading the performance of the proposed MC CDMA system. Also, we have evaluated the degree of performance improvement in the proposed MC CDMA system. As the result of analysis, a CCI canceller is better efficient than an adaptive array antenna in the performance improvement and that the performance improvement becomes large as the number of users increases when multi-interference cancellation techniques are used in cascade form. Also, we found that performance of $10^{-5}$ in a point of view BER could be achieved when $E_b/N_o$ is more than 10 dB.

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Performance Analysis of Multi-Carrier CDMA Systems under Indoor Wireless Environment with Impulsive Noise (임펄스성 잡음이 존재하는 실내 무선 환경에서 Multi-Carrier CDMA 시스템의 성능 분석)

  • Lee, Young-Choon;Park, Ki-Sik;Cho, Sung-Joon
    • Journal of Advanced Navigation Technology
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    • v.7 no.1
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    • pp.30-37
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    • 2003
  • In this paper, we have analyzed the BER (Bit Error Rate) performance of MC-CDMA systems under indoor wireless environment with class A impulsive noise suggested by Middleton. For the performance evaluation, we considered from strong to weak impulsive noise characteristics. And we have evaluated the degree of performance improvement by using turbo code as a compensation technique to impulsive noise. From the result of analysis, it is found powerful performance improvement scheme must be adopted in the system under impulsive noise environment, and when turbo code scheme is adopted, system BER performance is improved by the $10^{-2}$. As the impulsive noise characteristics approaches AWGN characteristics, the degree of performance improvement by adopting turbo code become larger.

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A Study on the Performance Improvement of Trellis Coded Orthogonal MC/FH-CDMA System in Wireless Channel (무선 통신로에서 Trellis Coded Orthogonal MC/FH-CDMA 시스템의 성능 개선에 관한 연구)

  • Lee, Moon Seung
    • Journal of Advanced Navigation Technology
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    • v.5 no.1
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    • pp.11-18
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    • 2001
  • In this paper, we evaluated the performance of Orthogonal MC/FH-CDMA system considering the hit of frequency hopping patterns, and obtained the degree of the performance improvement by adopting TCM scheme under frequency selective Rayleigh fading channel. From the performance analysis, it is known that the error performance is improved, since delay time relative to symbol time is reduced as the number of carrier is increased. On the other hand, it is found that BER performance is improved about $5{\times}10^{-2}$ degree by adopting TCM scheme, and higher S/N is required if the QoS of voice (BER = $10^{-3}$) must be achieved.

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An Analytical Expression for BER Performance of Intelligent Reflecting Surface Assisted NOMA

  • Chung, Kyuhyuk
    • International Journal of Internet, Broadcasting and Communication
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    • v.14 no.2
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    • pp.23-29
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    • 2022
  • To improve spectrum and energy efficiency in the fifth generation (5G) wireless channels, intelligent reflecting surface (IRS) transmissions have been envisioned, possibly towards the sixth generation (6G) networks. In this paper, we analyze the bit-error rate (BER) performance of intelligent reflecting surface (IRS) assisted non-orthogonal multiple access (NOMA) systems. First, we derive a closed-form expression of the BER in terms of Q functions. Then we analyze the BER improvement of the IRS NOMA system over the conventional NOMA system with respect to the power allocation. Furthermore, we also demonstrate numerically the BER improvement of the IRS NOMA network over the conventional NOMA network in respect of the number of reflecting devices.

Performance Analysis of Multi-Carrier CDMA System by Co-Channel Interference Cancellation Technique in Mobile Communication Channel (이동 통신 채널에서 동일 채널 간섭 제거 기법에 의한 Multi-Carrier CDMA 시스템의 성능 분석)

  • 이영춘;박기식;조성언;조성준
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.5 no.6
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    • pp.1056-1061
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    • 2001
  • In this paper we have evaluated the degree of performance improvement in Multi-Carrier CDMA system adopting CCI canceller against MUI under mobile channel coexisting MU which is a major interference degrading the performance of Multi-carrier CDMA system. As a result of analysis, BER performance was improved by adopting CCI canceller and it was found that the amount of performance improvement was largely increased as Eb/No became higher. As an example, in case that data service BER = 10$^{-5}$ must be achieved with $E_{b/}$ $N_{o}$ = 12 ㏈, 4 users could be supported without CCI canceller while 30 users could be supported with CCI canceller, Also, we found that performance improving effect of 5$\times$10$^{-3}$ in a point of view BER could be achieved by adopting CCI canceller with fixed $E_{b/}$ $N_{o}$. o/. o/.

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