• 제목/요약/키워드: Correlated fading channels

검색결과 43건 처리시간 0.022초

Performance Analysis of Transmit Diversity in Multiuser Data Networks With Fading Correlation

  • Zhang, Kai;Niu, Zhisheng
    • Journal of Communications and Networks
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    • 제10권4호
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    • pp.444-450
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    • 2008
  • This paper studies the performance of multiuser data networks with transmit diversity under correlated fading channels. Previous work shows that correlated fading reduces the link performance of multiple antenna systems, but how correlated fading affects the throughput of multiuser data networks is still unknown since the throughput depends not only on the link performance but also on the multiuser diversity. We derive the throughput of the multiuser data networks with various transmit diversity schemes under correlated fading channels. The impact of correlated fading on the throughput is investigated. Analytical and simulation results show that, although correlated fading is harmful for link performance, it increases the throughput of the multiuser data networks if the transmit scheme is appropriately selected.

New Evaluation on Maximum Ratio Diversity Reception for the Detection of Signals over Correlated Nakagami Fading Channels

  • Hong Wan-Pyo;Kim Chang-Hwan
    • Journal of information and communication convergence engineering
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    • 제2권3호
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    • pp.145-148
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    • 2004
  • The performances of M-ary signals using L-branch maximum ratio combining (MRC) diversity reception in correlated Nakagami fading channels are derived theoretically. The coherent reception of M-ary differential phase shift keying (MDPSK), phase shift keying (MPSK), and quadrature amplitude modulation (MQAM) is considered. It is assumed that the fading parameters in each diversity branch are identical. The general formula for evaluating symbol error rate (SER) of M-ary signals in the independent branch diversity system is presented using the integral-form expressions.

상관된 페이딩 채널에서 하이브리드 ARQ를 사용하는 V-BLAST 시스템의 수율 (Throughput of V-BLAST System using Hybrid ARQ in Correlated Fading Channels)

  • 김봉회;황승훈
    • 대한전자공학회논문지TC
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    • 제45권1호
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    • pp.66-71
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    • 2008
  • 본 논문에서는 H-ARQ를 위한 NACK 신호를 이용한 안테나 스위칭 방식을 제안하고 V-BLAST 시스템에서 분석하였다. 여기서 전송 안테나는 재전송시 번갈아 스위칭 되어 동작한다. 상관된 페이딩 채널에서 제안된 방식의 채널 용량을 해석적으로 분석함으로써, 채널 상관성의 악영향이 안테나 스위칭 방식으로 줄어듦을 보인다. 시뮬레이션 결과를 통해 상관된 페이딩 채널에서 평균 수율은 큰 복잡도의 증가 없이 개선되어질 수 있음을 보인다.

Closed-Form Expressions for Selection Combining System Statistics over Correlated Generalized-K Fading Channels in the Presence of Interference

  • Nikolic, Bojana Z.;Stefanovic, Mihajlo C.;Panic, Stefan R.;Anastasov, Jelena A.;Milosevic, Borivoje
    • ETRI Journal
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    • 제33권3호
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    • pp.320-325
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    • 2011
  • This paper considers the effects of simultaneous correlated multipath fading and shadowing on the performances of a signal-to-interference ratio (SIR)-based dual-branch selection combining (SC) diversity receiver. This analysis includes the presence of cochannel interference. A generalized fading/shadowing channel model in an interference-limited correlated fading environment is modeled by generalized-K distribution. Closed-form expressions are obtained for probability density function and cumulative distribution function of the SC output SIR, as well as for the outage probability. Based on this, the influence of various fading and shadowing parameter values and the correlation level on the outage probability is examined.

Dual Diversity over Correlated Ricean Fading Channels

  • Bithas Petros S.;Sagias Nikos C.;Mathiopoulos P. Takis
    • Journal of Communications and Networks
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    • 제9권1호
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    • pp.67-74
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    • 2007
  • The performance of dual diversity receivers operating over correlated Ricean fading channels is analyzed. Using a previously derived rapidly converging infinite series representation for the bivariate Ricean probability density function, analytical expressions for the statistics of dual-branch selection combining, maximal-ratio combining, and equal-gain combining output signal-to-noise ratio (SNR) are derived. These expressions are employed to obtain novel analytical formulae for the average output SNR, amount of fading, average bit error probability, and outage probability. The proposed mathematical analysis is used to study various novel performance evaluation results with parameters of interest the fading severity, average input SNRs, and the correlation coefficient. The series convergence rate is also examined verifying the fast convergence of the analytical expressions. The accuracy of most of the theoretical performance evaluation results are validated by means of computer simulations.

Differential Space Time Coding based on Different Unitary Matrices Sets

  • Lee, Kwang-Jae;Kim, Chang-Joo;Yoo, Hyun-Seok;Kim, Sung-Hun;Lee, Moon-Ho
    • Journal of electromagnetic engineering and science
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    • 제6권4호
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    • pp.209-216
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    • 2006
  • This paper investigates a distinct set of complex unitary matrices for QPSK differential space time coding. After properly selecting the initial transmission matrix and unitary matrices we find that the different combinations of them could lead different BER performance over slow/fast Rayleigh fading channels and antennas correlated channels. The numerical results show that the proper selection of the initial transmission matrix and the set of unitary matrices can efficiently improve the bit error rate performance, especially for the antennas correlated fading channel. The computer simulations are evaluated over slow and fast Rayleigh fading channels.

New Evaluation on Correlated MRC Diversity Reception for the Detection of Signals over Wireless Fading Channels

  • Kim, Chang-Hwan;Kim, Hyeong-Kyo
    • 융합신호처리학회논문지
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    • 제10권2호
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    • pp.136-140
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    • 2009
  • The performances of M-ary signals using L-branch maximum ratio combining (MRC) diversity reception in correlated Nakagami fading channels are derived theoretically. The coherent reception of M-ary differential phase shift keying (MDPSK), phase shift keying (MPSK), and quadrature amplitude modulation (MQAM) is considered. It is assumed that the fading parameters in each diversity branch are identical. The general formula for evaluating symbol error rate (SER) of M-ary signals in the independent branch diversity system is presented using the integral-form expressions. Until now, results did not extend to the various M-ary case for a coherent reception. The numerical results presented in this paper are expected to provide information for the design of radio system using M-ary modulation method for above mentioned channel environment.

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Capacity Bounds on the Ergodic Capacity of Distributed MIMO Systems over K Fading Channels

  • Li, XingWang;Wang, Junfeng;Li, Lihua;Cavalcante, Charles C.
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제10권7호
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    • pp.2992-3009
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    • 2016
  • The performance of D-MIMO systems is not only affected by multipath fading but also from shadowing fading, as well as path loss. In this paper, we investigate the ergodic capacity of D-MIMO systems operating in non-correlated K fading (Rayleigh/Gamma) channels. With the aid of majorization and Minkowski theory, we derive analytical closed-form expressions of the upper and lower bounds on the ergodic capacity for D-MIMO systems over non-correlated K fading channels, which are quite general and applicable for arbitrary signal-to-noise ratio (SNR) and the number of transceiver antennas. To intuitively reveal the impacts of system and fading parameters on the ergodic capacity, we deduce asymptotic approximations in the high and low SNR regimes. Finally, we pursue the massive MIMO systems analysis for the lower bound and derive closed-form expressions when the number of antennas at BS grows large, and when the number of antennas at transceivers becomes large with a fixed and finite ratio. It is demonstrated that the proposed expressions on the ergodic capacity accurately match with the theoretical analysis.

Effect of Microdiversity and Macrodiversity on Average Bit Error Probability in Shadowed Fading Channels in the Presence of Interference

  • Panajotovic, Aleksandra S.;Stefanovic, Mihajlo C.;Draca, Dragan Lj.
    • ETRI Journal
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    • 제31권5호
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    • pp.500-505
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    • 2009
  • The detrimental effect of short-term fading and shadowing can be mitigated using microdiversity and macrodiversity systems, respectively. In this paper, implementation of selection combining at both micro and macro levels to improve system performance is analyzed. An assessment of the performance of such a system is carried out by considering the desired signal as Rician fading with lognormal shadowing and cochannel interference signal as Rayleigh fading superimposed over lognormal shadowing. The proposed analysis is complemented by various performance evaluation results, including the effects on overall system performance of fading severity, shadowing spreads and branch correlation existing at the base station, and correlation between base stations.

BER of Rectangular QAM signals with MRC over Correlated Nakagami Fading Channels

  • Baek Kyung Hoon;Hyun Kwang Min;Yoon Dong Weon;Park Sang Kyu
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2004년도 학술대회지
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    • pp.653-657
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    • 2004
  • The average bit error rate (HER) performance of a Gray coded arbitrary rectangular quadrature amplitude modulation (AR-QAM) signal with maximal ratio combining (MRC) diversity in an arbitrarily correlated Nakagami-m fading channel is derived and analyzed. The derived two types of general solutions are a simple closed-form and an integral form, depending on the types of the values (integer and non-integer) of the fading parameter. Using the derived equations in this paper, we analyzed the HER performances numerically based on the practical base station antenna configuration. The results show that MRC reception is a very effective scheme so far even though the combined signals are not independent each other because of the correlation values. The antenna height and separation of the MRC system relate to the correlation coefficient value between antennas, and go a long way with the diversity advantage. In particular, it is needed to be determined the antenna height that is carefully do for the diversity advantage because the correlation coefficient and the antenna height gain are contrary to each other from the aspect of the system performance. The expressions presented here can offer a convenient way to evaluate the exact HER performance of an arbitrary rectangular QAM signal with MRC diversity reception for various cases of practical interest on a correlated Nakagami fading channel.

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