This paper investigates the effective capacity of a point-to-point ultra-reliable low latency communication(URLLC)transmission over multiple parallel sub-channels at finite blocklength(FBL)with imperfect channel state...This paper investigates the effective capacity of a point-to-point ultra-reliable low latency communication(URLLC)transmission over multiple parallel sub-channels at finite blocklength(FBL)with imperfect channel state information(CSI).Based on reasonable assumptions and approximations,we derive the effective capacity as a function of the pilot length,decoding error probability,transmit power and the sub-channel number.Then we reveal significant impact of the above parameters on the effective capacity.A closed-form lower bound of the effective capacity is derived and an alternating optimization based algorithm is proposed to find the optimal pilot length and decoding error probability.Simulation results validate our theoretical analysis and show that the closedform lower bound is very tight.In addition,through the simulations of the optimized effective capacity,insights for pilot length and decoding error probability optimization are provided to evaluate the optimal parameters in realistic systems.展开更多
In this article, an exact closed-form expression is derived for outage probability of decode-and-forward (DF) cooperative communications over independent identically distributed Nakagami-m fading channels. Simulatio...In this article, an exact closed-form expression is derived for outage probability of decode-and-forward (DF) cooperative communications over independent identically distributed Nakagami-m fading channels. Simulation results verify that the theoretical expressions for the outage probability are correct. The optimal power allocation based on the derived outage probability is also studied.展开更多
In this article, the outage probability behavior of a relay network over Nakagami-m fading channels is analyzed. Both reactive and proactive opportunistic decode-and-forward (DAF) strategies are considered. The clos...In this article, the outage probability behavior of a relay network over Nakagami-m fading channels is analyzed. Both reactive and proactive opportunistic decode-and-forward (DAF) strategies are considered. The closed-form solutions to the outage probabilities on both opportunistic DAF strategies are derived. Simulation results confirm the presented mathematical analysis.展开更多
We derive closed-form expressions for outage probability and symbol error rate(SER) of opportunistic relaying(OR) and selection cooperation(SC).For the amplify-and-forward relay selection scheme,comparison between two...We derive closed-form expressions for outage probability and symbol error rate(SER) of opportunistic relaying(OR) and selection cooperation(SC).For the amplify-and-forward relay selection scheme,comparison between two selection strategies over independent non-identically distributed Nakagami-m fading channels via analytical and simulation results is given in terms of the outage probability and SER.Simulation results show that OR performs better than SC.展开更多
The novel closed-form expressions for the average channel capacity of dual selection diversity is presented, as well as, the bit-error rate (BER) of several coherent and noncoherent digital modulation schemes in the...The novel closed-form expressions for the average channel capacity of dual selection diversity is presented, as well as, the bit-error rate (BER) of several coherent and noncoherent digital modulation schemes in the correlated Weibull fading channels with nonidentical statisticS. The results are expressed in terms of Meijer's Gfunction, which can be easily evaluated numerically. The simulation results are presented to validate the proposed theoretical analysis and to examine the effects of the fading severity on the concerned quantities.展开更多
In this paper, a new observation equation of non-Gaussian frequency selective fading Bell Labs layered space time (BLAST) architecture system is proposed, which is used for frequency selective fading channels and no...In this paper, a new observation equation of non-Gaussian frequency selective fading Bell Labs layered space time (BLAST) architecture system is proposed, which is used for frequency selective fading channels and non-Gaussian noise in an application environment of BLAST system. With othogonal matrix triangularization (QR decomposition) of the channel matrix, the static observation equation of frequency selective fading BLAST system is transformed into a dynamic state space model, and then the particle filter is used for space-time layered detection. Making the full use of the finite alphabet of the digital modulation communication signal, the optimal proposal distribution can be chosen to produce particle and update the weight. Incorporated with current method of reducing error propagation, a new space-time layered detection algorithm is proposed. Simulation result shows the validity of the proposed algorithm.展开更多
Cognitive radio allows Secondary Users(SUs) to dynamically use the spectrum resource licensed to Primary Users(PUs),and significantly improves the efficiency of spectrum utilization and is viewed as a promising techno...Cognitive radio allows Secondary Users(SUs) to dynamically use the spectrum resource licensed to Primary Users(PUs),and significantly improves the efficiency of spectrum utilization and is viewed as a promising technology.In cognitive radio networks,the problem of power control is an important issue.In this paper,we mainly focus on the problem of power control for fading channels in cognitive radio networks.The spectrum sharing underlay scenario is considered,where SUs are allowed to coexist with PUs on the condition that the outage probability of PUs is below the maximum outage probability threshold limitation due to the interference caused by SUs.Moreover,besides the outage probability threshold which is defined to protect the performance of PUs,we also consider the maximum transmit power constraints for each SU.With such a setup,we emphasize the problem of power control to minimize the outage probability of each SU in fading channels.Then,based on the statistical information of the fading channel,the closed expression for outage probability is given in fading channels.The Dual-Iteration Power Control(DIPC) algorithm is also proposed to minimize the outage probability based on Perron-Frobenius theory and gradient descent method under the constraint condition.Finally,simulation results are illustrated to demonstrate the performance of the proposed scheme.展开更多
This paper characterizes the joint effects of plant uncertainty,Denial-of-Service(DoS)attacks,and fading channel on the stabilization problem of networked control systems(NCSs).It is assumed that the controller remote...This paper characterizes the joint effects of plant uncertainty,Denial-of-Service(DoS)attacks,and fading channel on the stabilization problem of networked control systems(NCSs).It is assumed that the controller remotely controls the plant and the control input is transmitted over a fading channel.Meanwhile,considering the sustained attack cycle and frequency of DoS attacks are random,the packet-loss caused by DoS attacks is modelled by a Markov process.The sampled-data NCS is transformed into a stochastic form with Markov jump and uncertain parameter.Then,based on Lyapunov functional method,linear matrix inequality(LMI)-based sufficient conditions are presented to ensure the stability of uncertain NCSs.The main contribution of this article lies in the construction of NCSs based on DoS attacks into Markov jump system(MJS)and the joint consideration of fading channel and plant uncertainty.展开更多
Zero Crossing Digital Phase Locked Loop with Arc Sine block (AS-ZCDPLL) is used to linearize the phase difference detection, and enhance the loop performance. The loop has faster acquisition, less steady state phase e...Zero Crossing Digital Phase Locked Loop with Arc Sine block (AS-ZCDPLL) is used to linearize the phase difference detection, and enhance the loop performance. The loop has faster acquisition, less steady state phase error, and wider locking range compared to the conventional ZCDPLL. This work presents a Zero Crossing Digital Phase Locked Loop with Arc Sine block (ZCDPLL-AS). The performance of the loop is analyzed under mobile faded channel conditions. The mobile channel is assumed to be two path fading channel corrupted by additive white Gaussian noise (AWGM). It is shown that for a constant filter gain, the frequency spread has no effect on the steady state phase error variance when the loop is subjected to a phase step. For a frequency step and under the same conditions, the effect on phase error is minimal.展开更多
This paper provides an analytical framework for the outage probability evaluation of dual-hop decode-and-forward relay systems operating over κ-μ fading channels in the presence of co-channel interference.The interf...This paper provides an analytical framework for the outage probability evaluation of dual-hop decode-and-forward relay systems operating over κ-μ fading channels in the presence of co-channel interference.The interferers are independent non-identically distributed κ-μ fading.An accurate analytical-form expression for the cumulative distribution function of the received signal power to interference and noise ratio is derived.Various numerical results are compared with Monte Carlo simulation results in order to corroborate the accuracy of the proposed expressions.Our results show that increasing the value of kappa of main links will decrease the outage probability of relay systems.Furthermore,the system performance degrades with the number of interferences.展开更多
In this paper,the asymptotic performance of arbitrary rectangular Quadrature Amplitude Modulation (QAM) signals over fading channels is investigated. A novel unified asymptotic average Symbol Error Probability (SEP) e...In this paper,the asymptotic performance of arbitrary rectangular Quadrature Amplitude Modulation (QAM) signals over fading channels is investigated. A novel unified asymptotic average Symbol Error Probability (SEP) expression is derived in terms of diversity and coding gain. The validity and accuracy of the analytical result are verified by means of computer simulations. Furthermore,the results presented are very easy to be extended to the systems with multi-channel diversity receivers.展开更多
In this paper, we consider the secure data transmission over α-η-κ-μ fading channels, which are recently proposed to encompass nearly all the well-known statistical models adopted in the literature. In particular,...In this paper, we consider the secure data transmission over α-η-κ-μ fading channels, which are recently proposed to encompass nearly all the well-known statistical models adopted in the literature. In particular, we address the secrecy performance in terms of the average secrecy capacity(ASC) and the secrecy outage probability(SOP), for which novel analytical expressions are derived. Simulation results verify the analysis and demonstrate the impact of the physical parameters on the secrecy performance of this new channel fading model.展开更多
The problem of soft-input so,output ( SISO ) detection for time-varying frequency-selec- tive fading channels is considered. Based on a suitably-designed factor graph and the sum-product al- gorithm, a low-complexit...The problem of soft-input so,output ( SISO ) detection for time-varying frequency-selec- tive fading channels is considered. Based on a suitably-designed factor graph and the sum-product al- gorithm, a low-complexity iterative message passing scheme is proposed for joint channel estima- tion, equalization and decoding. Two kinds of schedules (parallel and serial) are adopted in message updates to produce two algorithms with different latency. The computational complexity per iteration of the proposed algorithms grows only linearly with the channel length, which is a significantly de- crease compared to the optimal maximum a posteriori (MAP) detection with the exponential com- plexity. Computer simulations demonstrate the effectiveness of the proposed schemes in terms of bit error rate performance.展开更多
In most of the previous researches on the multiple-input multiple-output (MIMO) channel estimation, the fading model has been assumed to be Rayleigh distributed. However, the Rician fading model is suitable for microc...In most of the previous researches on the multiple-input multiple-output (MIMO) channel estimation, the fading model has been assumed to be Rayleigh distributed. However, the Rician fading model is suitable for microcellular mobile systems or line of sight mode of WiMAX. In this paper, the training based channel es-timation (TBCE) scheme in the spatially correlated Rician flat fading MIMO channels is investigated. First, the least squares (LS) channel estimator is probed. Simulation results show that the Rice factor has no effect on the performance of this estimator. Then, a new linear minimum mean square error (LMMSE) technique, appropriate for Rician fading channels, is proposed. The optimal choice of training sequences with mean square error (MSE) criteria is investigated for these estimators. Analytical and numerical results show that the performance of proposed estimator in the Rician channel model compared with Rayleigh one is much better. It is illustrated that when the channel Rice factor and/or the correlation coefficient increase, the per-formance of the proposed estimator significantly improves.展开更多
Space-Time Frequency (STF) codes for MIMO-OFDM over block-fading channel can achieve rate?? Mt and full-diversity Mt Mr Mb L which is the product of the number of transmit antennas Mt, receive antennas Mr, fading bloc...Space-Time Frequency (STF) codes for MIMO-OFDM over block-fading channel can achieve rate?? Mt and full-diversity Mt Mr Mb L which is the product of the number of transmit antennas Mt, receive antennas Mr, fading blocks Mb and channel taps L. In this article, time permutation is proposed to provide independent block-fading over Jake’s Doppler power spectrum channel. Moreover, we show the performance variations of STF code as channel delay spread changes. Therefore, we introduce a frequency/time permutation technique in order to remove the frequency correlation among sub-carriers, which subsequently increases the coding gain and achieves maximum diversity. Finally, the symbol error rate (SER) performance of the proposed time/frequency permuted STF codes over independent and correlated MIMO antenna branches under Nakagami fading channel is simulated. We show that the proposed systems provide better performance and more robust to large values of antennas correlation coefficients in comparison with the un-interleaved one.展开更多
This paper investigates the outage performance of a cognitive relay network considering best relay selection in Nakagami-m fading environment. The secondary user is allowed to use the spectrum when it meets the interf...This paper investigates the outage performance of a cognitive relay network considering best relay selection in Nakagami-m fading environment. The secondary user is allowed to use the spectrum when it meets the interference constraints predefined by primary user. Due to deep fading, cognitive source is unable to communicate directly with cognitive destination. As such, multiple relays are ready to deliver the signal from the cognitive source to cognitive destination. We select a single best relay and the selected relay uses decode-and-forward protocol. Specifically, we derive the exact outage probability expression, which provides an efficient means to evaluate the effects of several parameters. Finally, numerical simulation results are presented, which validate the correctness of the analytical analysis.展开更多
Space time block coding is a modulation scheme recently discovered for the transmit an- tenna diversity to combat the effects of wireless fading channels. Using the equivalent Single-Input Single-Output (SISO) model, ...Space time block coding is a modulation scheme recently discovered for the transmit an- tenna diversity to combat the effects of wireless fading channels. Using the equivalent Single-Input Single-Output (SISO) model, this paper presents closed-form expressions for the exact Symbol Error Rate (SER) and Bit Error Rate (BER) of Orthogonal Space-Time Block Codes (OSTBCs) with M-ary Phase-Shift Keying (MPSK) and M-ary Quadrature Amplitude Modulation (MQAM) over flat un- correlated Nakagami-m and Ricean fading channels.展开更多
The effects of scatterers, fluctuation parameter and propagation clusters significantly affect the performance of κ-μ shadowed fading channel. On the other hand, opportunistic relaying is an efficient technique to i...The effects of scatterers, fluctuation parameter and propagation clusters significantly affect the performance of κ-μ shadowed fading channel. On the other hand, opportunistic relaying is an efficient technique to improve the performance of fading channels reducing the effects of aforementioned parameters. Motivated by these issues, in this paper, a secure wireless multicasting scenario through κ-μ shadowed fading channel is considered in the presence of multiple eavesdroppers with opportunistic relaying. The main purpose of this paper is to ensure the security level in wireless multicasting compensating the loss of security due to the effects of power ratio between dominant and scattered waves, fluctuation parameter, and the number of propagation clusters, multicast users and eavesdroppers, by opportunistic relaying technique. The closed-form analytical expressions are derived for the probability of non-zero secrecy multicast capacity (PNSMC) and the secure outage probability for multicasting (SOPM) to understand the insight of the effects of above parameters. The results show that the loss of security in multicasting through κ-μ shadowed fading channel can be significantly enhanced using opportunistic relaying technique by compensating the effects of scatterers, fluctuation parameter, and the number of propagation clusters, multicast users and eavesdroppers.展开更多
基金supported by the National Natural Science Foundation of China under grant 61941106。
文摘This paper investigates the effective capacity of a point-to-point ultra-reliable low latency communication(URLLC)transmission over multiple parallel sub-channels at finite blocklength(FBL)with imperfect channel state information(CSI).Based on reasonable assumptions and approximations,we derive the effective capacity as a function of the pilot length,decoding error probability,transmit power and the sub-channel number.Then we reveal significant impact of the above parameters on the effective capacity.A closed-form lower bound of the effective capacity is derived and an alternating optimization based algorithm is proposed to find the optimal pilot length and decoding error probability.Simulation results validate our theoretical analysis and show that the closedform lower bound is very tight.In addition,through the simulations of the optimized effective capacity,insights for pilot length and decoding error probability optimization are provided to evaluate the optimal parameters in realistic systems.
文摘In this article, an exact closed-form expression is derived for outage probability of decode-and-forward (DF) cooperative communications over independent identically distributed Nakagami-m fading channels. Simulation results verify that the theoretical expressions for the outage probability are correct. The optimal power allocation based on the derived outage probability is also studied.
文摘In this article, the outage probability behavior of a relay network over Nakagami-m fading channels is analyzed. Both reactive and proactive opportunistic decode-and-forward (DAF) strategies are considered. The closed-form solutions to the outage probabilities on both opportunistic DAF strategies are derived. Simulation results confirm the presented mathematical analysis.
基金the National Natural Science Foundation of China(No.60972050)the National Basic Research Program (973) of China(No.2009CB3020402)the Jiangxi Province Science Foundation for Youths(No.20122BAB211041)
文摘We derive closed-form expressions for outage probability and symbol error rate(SER) of opportunistic relaying(OR) and selection cooperation(SC).For the amplify-and-forward relay selection scheme,comparison between two selection strategies over independent non-identically distributed Nakagami-m fading channels via analytical and simulation results is given in terms of the outage probability and SER.Simulation results show that OR performs better than SC.
基金the National High-Tech Research and Development Program (2002AA123032)the Innovative Research Team Program of UESTC, China.
文摘The novel closed-form expressions for the average channel capacity of dual selection diversity is presented, as well as, the bit-error rate (BER) of several coherent and noncoherent digital modulation schemes in the correlated Weibull fading channels with nonidentical statisticS. The results are expressed in terms of Meijer's Gfunction, which can be easily evaluated numerically. The simulation results are presented to validate the proposed theoretical analysis and to examine the effects of the fading severity on the concerned quantities.
文摘In this paper, a new observation equation of non-Gaussian frequency selective fading Bell Labs layered space time (BLAST) architecture system is proposed, which is used for frequency selective fading channels and non-Gaussian noise in an application environment of BLAST system. With othogonal matrix triangularization (QR decomposition) of the channel matrix, the static observation equation of frequency selective fading BLAST system is transformed into a dynamic state space model, and then the particle filter is used for space-time layered detection. Making the full use of the finite alphabet of the digital modulation communication signal, the optimal proposal distribution can be chosen to produce particle and update the weight. Incorporated with current method of reducing error propagation, a new space-time layered detection algorithm is proposed. Simulation result shows the validity of the proposed algorithm.
文摘Cognitive radio allows Secondary Users(SUs) to dynamically use the spectrum resource licensed to Primary Users(PUs),and significantly improves the efficiency of spectrum utilization and is viewed as a promising technology.In cognitive radio networks,the problem of power control is an important issue.In this paper,we mainly focus on the problem of power control for fading channels in cognitive radio networks.The spectrum sharing underlay scenario is considered,where SUs are allowed to coexist with PUs on the condition that the outage probability of PUs is below the maximum outage probability threshold limitation due to the interference caused by SUs.Moreover,besides the outage probability threshold which is defined to protect the performance of PUs,we also consider the maximum transmit power constraints for each SU.With such a setup,we emphasize the problem of power control to minimize the outage probability of each SU in fading channels.Then,based on the statistical information of the fading channel,the closed expression for outage probability is given in fading channels.The Dual-Iteration Power Control(DIPC) algorithm is also proposed to minimize the outage probability based on Perron-Frobenius theory and gradient descent method under the constraint condition.Finally,simulation results are illustrated to demonstrate the performance of the proposed scheme.
基金supported in part by the National Natural Science Foundation of China(Nos.62173206,62103229)the China Postdoctoral Science Foundation(Nos.2021M691849,2021M692024)+1 种基金the Natural Science Foundation of Shandong Province(Nos.ZR2021ZD13,ZR2021QF026)the National Key R&D Program of China(No.2021YFE0193900)。
文摘This paper characterizes the joint effects of plant uncertainty,Denial-of-Service(DoS)attacks,and fading channel on the stabilization problem of networked control systems(NCSs).It is assumed that the controller remotely controls the plant and the control input is transmitted over a fading channel.Meanwhile,considering the sustained attack cycle and frequency of DoS attacks are random,the packet-loss caused by DoS attacks is modelled by a Markov process.The sampled-data NCS is transformed into a stochastic form with Markov jump and uncertain parameter.Then,based on Lyapunov functional method,linear matrix inequality(LMI)-based sufficient conditions are presented to ensure the stability of uncertain NCSs.The main contribution of this article lies in the construction of NCSs based on DoS attacks into Markov jump system(MJS)and the joint consideration of fading channel and plant uncertainty.
文摘Zero Crossing Digital Phase Locked Loop with Arc Sine block (AS-ZCDPLL) is used to linearize the phase difference detection, and enhance the loop performance. The loop has faster acquisition, less steady state phase error, and wider locking range compared to the conventional ZCDPLL. This work presents a Zero Crossing Digital Phase Locked Loop with Arc Sine block (ZCDPLL-AS). The performance of the loop is analyzed under mobile faded channel conditions. The mobile channel is assumed to be two path fading channel corrupted by additive white Gaussian noise (AWGM). It is shown that for a constant filter gain, the frequency spread has no effect on the steady state phase error variance when the loop is subjected to a phase step. For a frequency step and under the same conditions, the effect on phase error is minimal.
基金supported by the NSFC project under grant No.61101237the Fundamental Research Funds for the Central Universities No.2014JBZ001
文摘This paper provides an analytical framework for the outage probability evaluation of dual-hop decode-and-forward relay systems operating over κ-μ fading channels in the presence of co-channel interference.The interferers are independent non-identically distributed κ-μ fading.An accurate analytical-form expression for the cumulative distribution function of the received signal power to interference and noise ratio is derived.Various numerical results are compared with Monte Carlo simulation results in order to corroborate the accuracy of the proposed expressions.Our results show that increasing the value of kappa of main links will decrease the outage probability of relay systems.Furthermore,the system performance degrades with the number of interferences.
基金Supported by the National Natural Science Foundation of China (NSFC) (No. 90604035)the National 863 High-Tech R&D Program (No. 2007AA01Z228)the 111 Project (No. 111-2-14)
文摘In this paper,the asymptotic performance of arbitrary rectangular Quadrature Amplitude Modulation (QAM) signals over fading channels is investigated. A novel unified asymptotic average Symbol Error Probability (SEP) expression is derived in terms of diversity and coding gain. The validity and accuracy of the analytical result are verified by means of computer simulations. Furthermore,the results presented are very easy to be extended to the systems with multi-channel diversity receivers.
基金supported by the Fundamental Research Funds for the Center University of China under Grant HIT. MKSTISP. 2016 13
文摘In this paper, we consider the secure data transmission over α-η-κ-μ fading channels, which are recently proposed to encompass nearly all the well-known statistical models adopted in the literature. In particular, we address the secrecy performance in terms of the average secrecy capacity(ASC) and the secrecy outage probability(SOP), for which novel analytical expressions are derived. Simulation results verify the analysis and demonstrate the impact of the physical parameters on the secrecy performance of this new channel fading model.
基金Supported by the National Natural Science Foundation of China(61201181)Specialized Research Fund for the Doctoral Program of Higher Education(20121101120020)the Co-innovation Laboratory of Aerospace Broadband Network Technology
文摘The problem of soft-input so,output ( SISO ) detection for time-varying frequency-selec- tive fading channels is considered. Based on a suitably-designed factor graph and the sum-product al- gorithm, a low-complexity iterative message passing scheme is proposed for joint channel estima- tion, equalization and decoding. Two kinds of schedules (parallel and serial) are adopted in message updates to produce two algorithms with different latency. The computational complexity per iteration of the proposed algorithms grows only linearly with the channel length, which is a significantly de- crease compared to the optimal maximum a posteriori (MAP) detection with the exponential com- plexity. Computer simulations demonstrate the effectiveness of the proposed schemes in terms of bit error rate performance.
文摘In most of the previous researches on the multiple-input multiple-output (MIMO) channel estimation, the fading model has been assumed to be Rayleigh distributed. However, the Rician fading model is suitable for microcellular mobile systems or line of sight mode of WiMAX. In this paper, the training based channel es-timation (TBCE) scheme in the spatially correlated Rician flat fading MIMO channels is investigated. First, the least squares (LS) channel estimator is probed. Simulation results show that the Rice factor has no effect on the performance of this estimator. Then, a new linear minimum mean square error (LMMSE) technique, appropriate for Rician fading channels, is proposed. The optimal choice of training sequences with mean square error (MSE) criteria is investigated for these estimators. Analytical and numerical results show that the performance of proposed estimator in the Rician channel model compared with Rayleigh one is much better. It is illustrated that when the channel Rice factor and/or the correlation coefficient increase, the per-formance of the proposed estimator significantly improves.
文摘Space-Time Frequency (STF) codes for MIMO-OFDM over block-fading channel can achieve rate?? Mt and full-diversity Mt Mr Mb L which is the product of the number of transmit antennas Mt, receive antennas Mr, fading blocks Mb and channel taps L. In this article, time permutation is proposed to provide independent block-fading over Jake’s Doppler power spectrum channel. Moreover, we show the performance variations of STF code as channel delay spread changes. Therefore, we introduce a frequency/time permutation technique in order to remove the frequency correlation among sub-carriers, which subsequently increases the coding gain and achieves maximum diversity. Finally, the symbol error rate (SER) performance of the proposed time/frequency permuted STF codes over independent and correlated MIMO antenna branches under Nakagami fading channel is simulated. We show that the proposed systems provide better performance and more robust to large values of antennas correlation coefficients in comparison with the un-interleaved one.
文摘This paper investigates the outage performance of a cognitive relay network considering best relay selection in Nakagami-m fading environment. The secondary user is allowed to use the spectrum when it meets the interference constraints predefined by primary user. Due to deep fading, cognitive source is unable to communicate directly with cognitive destination. As such, multiple relays are ready to deliver the signal from the cognitive source to cognitive destination. We select a single best relay and the selected relay uses decode-and-forward protocol. Specifically, we derive the exact outage probability expression, which provides an efficient means to evaluate the effects of several parameters. Finally, numerical simulation results are presented, which validate the correctness of the analytical analysis.
基金the Natural Science Foundation of Liaoning Province (No.20042121) in part by the Open Topic Foundation of National Mobile Communications Research Laboratory of Southeast University (No.A2005011).
文摘Space time block coding is a modulation scheme recently discovered for the transmit an- tenna diversity to combat the effects of wireless fading channels. Using the equivalent Single-Input Single-Output (SISO) model, this paper presents closed-form expressions for the exact Symbol Error Rate (SER) and Bit Error Rate (BER) of Orthogonal Space-Time Block Codes (OSTBCs) with M-ary Phase-Shift Keying (MPSK) and M-ary Quadrature Amplitude Modulation (MQAM) over flat un- correlated Nakagami-m and Ricean fading channels.
基金Supported by the High Technology Research and Development Program of China (No. 2003AA12331007 ) and National Natural Science Foundation of China ( No. 60272079).
文摘The effects of scatterers, fluctuation parameter and propagation clusters significantly affect the performance of κ-μ shadowed fading channel. On the other hand, opportunistic relaying is an efficient technique to improve the performance of fading channels reducing the effects of aforementioned parameters. Motivated by these issues, in this paper, a secure wireless multicasting scenario through κ-μ shadowed fading channel is considered in the presence of multiple eavesdroppers with opportunistic relaying. The main purpose of this paper is to ensure the security level in wireless multicasting compensating the loss of security due to the effects of power ratio between dominant and scattered waves, fluctuation parameter, and the number of propagation clusters, multicast users and eavesdroppers, by opportunistic relaying technique. The closed-form analytical expressions are derived for the probability of non-zero secrecy multicast capacity (PNSMC) and the secure outage probability for multicasting (SOPM) to understand the insight of the effects of above parameters. The results show that the loss of security in multicasting through κ-μ shadowed fading channel can be significantly enhanced using opportunistic relaying technique by compensating the effects of scatterers, fluctuation parameter, and the number of propagation clusters, multicast users and eavesdroppers.