• Title/Summary/Keyword: M진 전송

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Analysis of M-ary Antipodal Communication System for Multiple Access in Additive White Gaussian Noise (AWGN에서 다중접속을 위한 M진 Antipodal 초광대역 통신 시스템의 성능 분석)

  • Lee, Jung-Suk;Kim, Jong-Han;Kim, Yoo-Chang;Kim, Jung-Sun;Kim, Won-Hoo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.1A
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    • pp.1-12
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    • 2002
  • Ultra Wideband (UWB) system uses wide band signal, which power spectral density likes as a noise floor, so UWB system can be used high speed communication without interfering with other communication system. As this system doesn't use radio frequency carrier. Its structure would be very simple and consume very low power. For the first time, we adopted Rayleigh monopulse multiple access system. And under the AWGN, we analysis and compare error probability, the number of user and data rate of the two methods that pulse position modulation and antipodal. In the result, We concluded that the antipodal method had much better probability of error, the number of user and data rate than PPM.

A Novel Differential Equal Gain Transmission Technique using M-PSK Constellations in MIMO System (MIMO 시스템에서 M-PSK 성운을 이용한 새로운 차분 동 이득 전송 기술)

  • Kim, Young-Ju;Seo, Chang-Won;Park, Noeyoon
    • Journal of the Institute of Electronics and Information Engineers
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    • v.52 no.1
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    • pp.24-31
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    • 2015
  • A differential codebook using M-ary phase shift keying (M-PSK) constellation as its codeword elements, is proposed for Long term evolution (LTE), LTE-Advanced (LTE-A), and/or WiMAX systems. Due to the temporal correlation of the adjacent channel, the consecutive precoding matrices are likely to be similar. This approach quantize only the differential information of the channel instead of the whole channel subspace, which virtually increase the codebook size to realize more accurate quantization of the channel. Especially, the proposed codebook has the same properties of LTE release-8 codebook that is, constant modulus, complexity reduction, and nested property. The mobile station can be designed by using a less expensive non-linear amplifier utilizing the constant modulus property. Computer simulations show that the capacity of the proposed codebook performs better than LTE release-8 codebook with the same amount of feedback information.

A Novel Dual-Layer Differential Equal Gain Transmission Technique Using M-PSK Constellations (M-PSK 성운을 이용한 새로운 이중계층 차분 동 이득 전송 기술)

  • Kim, Young-Ju;Seo, Chang-Won
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.26 no.7
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    • pp.627-635
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    • 2015
  • We propose a dual-layer differential equal-gain codebook design methodology for LTE-Advanced(LTE-A), IEEE802.ac, and radar system having multiple transmit and receive antennas, and make computer simulations to evaluate its link-level performaces. M-ary phase shift keying constellation is used as its codeword elements to utilize low-cost power amplifiers at mobile stations. Especially, the proposed codebook can meet radar systems requirement for the high-powered equal-gain transmission property. Due to the temporal correlation of the adjacent channel, the proposed differential codebook can quantize only the differential information of the channel instead of the whole channel subspace, which virtually increase the codebook size to realize more accurate quantization of the channel. The proposed codebook has the same properties of LTE codebook that is, constant modulus, complexity reduction, and nested property. Computer simulations show that the proposed codebook performs better than the conventional 8-ary codebooks with the same amount of feedback information.

Allowable Interference Criteria Between Digital FWSs (디지털 FWS간 허용 간섭 기준)

  • Lee, Ki-Hwan;Lee, Joo-Hwan;Suh, Kyoung-Whoan;Song, Ju-Bin
    • Journal of Broadcast Engineering
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    • v.13 no.4
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    • pp.479-487
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    • 2008
  • The method to determine allowable interference criteria is required due to new digital FWSs(Fixed Wireless Systems) adding to allowable frequency bands, besides current FWSs and digital FWSs. In this paper, we suggested a method to define allowable interference between digital FWSs. Types of interference for FWS were defined and channel characteristics were analyzed. Allowable interference criteria were analyzed using the suggested method for M-ary QAM modulations, which is typical modulation technique of digital FWS.

Performance of PPSM System in multipath channel for UWB Communication (다중경로 환경을 고려한 PPSM 임펄스 시스템의 성능 분석)

  • Park Ho-Hwan;Kim Jin-Su;Hwang Hyeon-Chyeol;Kwak Kyung-Sup
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.43 no.2 s.344
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    • pp.7-15
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    • 2006
  • Recently, Ultra-wideband (UWB) Communication systems have become a popular research topic. UWB system is characterized by the fact that the digital information represented by a subnanosecond pulses is transmitted through the air. In this paper, we consider the PPSM scheme that combine PPM and PSM. We provide the performance in AWGN and SV multipath channel which consists of $CM1\~CM4$. The optimal symbol set for M-ary system in multipath channel which shows good performance is also presented. The simulation results show that the performance in CM4 is worse than that in CMI due to long delay spread, many multipath components, 4-ary system outperforms binary system in Low$E_b/N_0$ but not in high $E_b/N_0$. We find system have the optimal symbol set in multipath channel.

SNR Estimation Based on Correlation of Decision Feedback Signal in OFDM System (OFDM 시스템에서 Decision Feedback 신호의 상관 관계를 이용하는 SNR 추정)

  • Kim, Seon-Ae;Ryu, Heung-Gyoon;Lee, Seung-Jun;Ko, Dong-Kuk
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.21 no.9
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    • pp.995-1004
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    • 2010
  • In the channel-varying environment, it is very important to estimate the signal to noise ratio(SNR) of received signal and to transmit the signal effectively for the modern communication system. The performance of existing non-data-aided (NDA) SNR estimation methods are substantially degraded for high level modulation scheme such as M-ary APSK or QAM. In this paper, we propose a SNR estimation method which uses zero point auto-correlation of received signal per block and auto-/cross- correlation of decision feedback signal in OFDM system. Proposed method can be studied into two Types; Type 1 can estimate SNR by zero point auto-correlation of decision feedback signal based on the second moment property. Type 2 uses both zero point auto-correlation and cross-correlation based on the fourth moment property. In block-by-block reception of OFDM system, these two SNR estimation methods can be possible for the practical implementation due to correlation based the estimation method and they show more stable estimation performance than the previous SNR estimation methods. Also, we mathematically derive the SNR estimation expression according to computational difference of auto-/cross-correlation. Finally, Monte Carlo simulations are used to verify the proposed method.