• Title/Summary/Keyword: equal gain combining (EGC)

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Approximate Expression of Bit Error Rate in Uplink MC-CDMA Systems with Equal Gain Combining

  • Develi, Ibrahim;Akdagli, Ali
    • Journal of Communications and Networks
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    • v.15 no.1
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    • pp.25-30
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    • 2013
  • Uplink multicarrier code-division multiple-access (MC-CDMA) with equal gain combining (EGC) over Nakagami fading channels is considered. An improved expression which is a feasible alternative for the bit error rate (BER) performance evaluation of MC-CDMA signals is proposed. Simulated annealing algorithm is employed to obtain the optimum value of the coefficients belonging to the proposed expression. Numerical examples show that the performance curves computed by the improved expression are in good agreement with the results obtained by the exact expression. Thus, the proposed expression can improve the accuracy of BER performance evaluation that has been realized by the approximate expression.

Blocking Effect Compensation using Diversity Technique (Diversity기법을 활용한 Blocking영향 보상)

  • Lee, Huikyu
    • Journal of Satellite, Information and Communications
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    • v.12 no.2
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    • pp.38-41
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    • 2017
  • Reception performance in land mobile satellite is decreased by obstacle. It is compensated with Diversity technique. In this paper, performances are analyzed with two type of method Equal Gain Combining(EGC) and Selcetive Combining(SC). To analyze, measured data using On-The-Move(OTM) terminal are used. In conclusion, SC method can increase performance. However, EGC method can improve perforamance only in rural region, but performance are decreased in urban region.

Performance Analysis of Pulse Position Modulation-Time Hopping Ultra Wide Band Systems with Antenna Diversity in Indoor Wireless Channel (실내 무선채널에서 안테나 다이버시티를 적용한 펄스위치변조-시간도약 초광대역 무선통신 시스템의 성능 분석)

  • Kim, Eun-Cheol;Kim, Sung-Ill;Park, Jae-Sung;Kim, Jin-Young
    • 한국정보통신설비학회:학술대회논문집
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    • 2008.08a
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    • pp.30-34
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    • 2008
  • In this paper, we analyze the performance of pulse position modulation-time hopping ultra wide band (PPM-TH UWB) systems with antenna diversity technique in indoor wireless channel. A modified Saleh and Valenzuela (SV) model is adopted as a UWB indoor channel model. Perfect synchronization between a transmitter and a receiver is assumed. Therefore, coherent equal gain combining (EGC) scheme to collect the energy available in the multipath components is investigated. It is shown that the performance is improved by increasing the number of antennas at the receiver. The results of this paper can be applied to the applications of UWB.

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Performance Improvement analysis of Acoustic Communication System using Receive Diversity (수신 다이버시티를 이용한 음향 통신 시스템의 성능 향상 분석)

  • Bok, Jun-Yeong;Ryu, Heung-Gyoon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.3A
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    • pp.198-204
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    • 2011
  • Acoustic communication system is a transmission technology sending sound and data simultaneously. However, data signal can be audible in this system when data is transmitted with high transmission power. The more transmission power is reduced, the more distance that can transmit data is shortened. Therefore, the study that increase the transmission distance is needed. In this paper, we would like to increase transmission distance by adapting receive diversity in acoustic communication system. We measure received performance of both proposed system and Single Input Sing Output (SISO) system according to distance with same transmission power. When SISO satisfies Bit Error Rate (BER) of $7{\times}10^{-3}$ at about 2m, Selection Combining (SC) technique satisfies 2 meters, and Equal Gain Combining (EGC) technique satisfies 4 meters.

Evolutionary Algorithm-based Space Diversity for Imperfect Channel Estimation

  • Ghadiri, Zienab Pouladmast;El-Saleh, Ayman A.;Vetharatnam, Gobi
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.5
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    • pp.1588-1603
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    • 2014
  • In space diversity combining, conventional methods such as maximal ratio combining (MRC), equal gain combining (EGC) and selection combining (SC) are commonly used to improve the output signal-to-noise ratio (SNR) provided that the channel is perfectly estimated at the receiver. However, in practice, channel estimation is often imperfect and this indeed deteriorates the system performance. In this paper, diversity combining techniques based on two evolutionary algorithms, namely genetic algorithm (GA) and particle swarm optimization (PSO) are proposed and compared. Numerical results indicate that the proposed methods outperform the conventional MRC, EGC and SC methods when the channel estimation is imperfect while it shows similar performance as that of MRC when the channel is perfectly estimated.

Partially Coherent MC-CDMA Downlink Performance in Rayleigh Fading Channels

  • Kim, Nam-Soo
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.12 no.3
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    • pp.470-477
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    • 2001
  • Multucarrier code-division multiple access(MC-CDMA) is one of the promising technique for high capacity wireless communication. Hower the carrier phase error and frequency offest cause the performance degradation of MC-CDMA due to the inter-carrier interference. In this work, downlink performance of the partially coherent MC-CDMA is analytically derived in Rayleigh fading channels. The bit error rate sensitivity by combining method, Maxiaml ratio combining (MRC)and Equal gain combining(EGC), is compared as functions of phase errors. multi-user interference, and received signal-to-noise ratio. The results show that the susceptibility for the performance degradation of EGc and MRC is negligible for loop SNR's of above 15 dB and above 10 dB, respectivtely.

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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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    • v.9 no.1
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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.

Minimizing Sensing Decision Error in Cognitive Radio Networks using Evolutionary Algorithms

  • Akbari, Mohsen;Hossain, Md. Kamal;Manesh, Mohsen Riahi;El-Saleh, Ayman A.;Kareem, Aymen M.
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.6 no.9
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    • pp.2037-2051
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    • 2012
  • Cognitive radio (CR) is envisioned as a promising paradigm of exploiting intelligence for enhancing efficiency of underutilized spectrum bands. In CR, the main concern is to reliably sense the presence of primary users (PUs) to attain protection against harmful interference caused by potential spectrum access of secondary users (SUs). In this paper, evolutionary algorithms, namely, particle swarm optimization (PSO) and genetic algorithm (GA) are proposed to minimize the total sensing decision error at the common soft data fusion (SDF) centre of a structurally-centralized cognitive radio network (CRN). Using these techniques, evolutionary operations are invoked to optimize the weighting coefficients applied on the sensing measurement components received from multiple cooperative SUs. The proposed methods are compared with each other as well as with other conventional deterministic algorithms such as maximal ratio combining (MRC) and equal gain combining (EGC). Computer simulations confirm the superiority of the PSO-based scheme over the GA-based and other conventional MRC and EGC schemes in terms of detection performance. In addition, the PSO-based scheme also shows promising convergence performance as compared to the GA-based scheme. This makes PSO an adequate solution to meet real-time requirements.