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Cross-Layer Design of Combining HARQ with Adaptive Modulation and Coding for Nakagami-m Fading Channels  [cached]
Cui-Qin Dai,Yu Rao,Li Jiang,Qian-Bin Chen
Journal of Communications , 2012, DOI: 10.4304/jcm.7.6.458-463
Abstract: In this paper, we propose a cross-layer design which combines adaptive modulation and coding (AMC) at the physical layer with a hybrid automatic repeat request (HARQ) protocol at the data link layer to minimize the packet error rate (PER) and maximize the spectral efficiency. By using Markov model to predict the channel condition of next frame according to the second order statistics characteristics of the former frame, we calculate the conditional probability density function and joint probability density function of signal to noise ratio (SNR). Further, we derive the packet error rate and average spectral efficiency in closed-form for transmission over Nakagami-m fading channels. Numerical results show that the proposed scheme can obtain lower PER and higher spectral efficiency compared with traditional HARQ protocols. The cross-layer design scheme combing type-III HARQ with AMC can achieve the highest spectral efficiency and the lowest PER than type-I HARQ and type-II HARQ.
Performance of a Multiple-Access DCSK-CC System over Nakagami-$m$ Fading Channels  [PDF]
Yi Fang,Lin Wang,Guanrong Chen
Computer Science , 2013,
Abstract: In this paper, we propose a novel cooperative scheme to enhance the performance of multiple-access (MA) differential-chaos-shift-keying (DCSK) systems. We provide the bit-error-rate (BER) performance and throughput analyses for the new system with a decode-and-forward (DF) protocol over Nakagami-$m$ fading channels. Our simulated results not only show that this system significantly improves the BER performance as compared to the existing DCSK non-cooperative (DCSK-NC) system and the multiple-input multiple-output DCSK (MIMO-DCSK) system, but also verify the theoretical analyses. Furthermore, we show that the throughput of this system approximately equals that of the DCSK-NC system, both of which have prominent improvements over the MIMO-DCSK system. We thus believe that the proposed system can be a good framework for chaos-modulation-based wireless communications.
Performance Study of Cooperative Diversity System over Nakagami-m Fading Channels  [PDF]
Jingning Wang,Xuejun Sha,Linan Sun,Zhongzhao Zhang
Information Technology Journal , 2009,
Abstract: In this study, a cooperative diversity scheme with decoded-and-forward plus amplify-and-forward is proposed by employing truncated stop-and-wait automatic repeat request for error control. All the transmission channels are assumed to exhibit Nakagami-m fading and the cross-layer performance is analyzed for the proposed scheme, such as the channel efficiency in physical layer, throughput and packet loss rate in link layer. The simulation results show that, the proposed scheme has the better cross-layer performance than other cooperative systems. By choosing a suitable partner, the proposed cooperative scheme can provide better performance than non-cooperative systems and spatial diversity gain can be obtained.
On the Performance of Multiple Antenna Cooperative Spectrum Sharing Protocol under Nakagami-m Fading  [PDF]
Shubha Sharma,Ankush Vashistha,Vivek Ashok Bohara
Computer Science , 2015,
Abstract: In a cooperative spectrum sharing (CSS) protocol, two wireless systems operate over the same frequency band albeit with different priorities. The secondary (or cognitive) system which has a lower priority, helps the higher priority primary system to achieve its target rate by acting as a relay and allocating a fraction of its power to forward the primary signal. The secondary system in return is benefited by transmitting its own data on primary system's spectrum. In this paper, we have analyzed the performance of multiple antenna cooperative spectrum sharing protocol under Nakagami-m Fading. Closed form expressions for outage probability have been obtained by varying the parameters m and Omega of the Nakagami-m fading channels. Apart from above, we have shown the impact of power allocation factor (alpha) and parameter m on the region of secondary spectrum access, conventionally defined as critical radius for the secondary system. A comparison between theoretical and simulated results is also presented to corroborate the theoretical results obtained in this paper
Another look in the Analysis of Cooperative Spectrum Sensing over Nakagami-$m$ Fading Channels  [PDF]
Debasish Bera,Sant S. Pathak,Indrajit Chakrabarty,George K. Karagiannidis
Mathematics , 2015,
Abstract: Modeling and analysis of cooperative spectrum sensing is an important aspect in cognitive radio systems. In this paper, the problem of energy detection (ED) of an unknown signal over Nakagami-$m$ fading is revisited. Specifically, an analytical expression for the local probability of detection is derived, while using the approach of ED at the individual secondary user (SU), a new fusion rule, based on the likelihood ratio test, is presented. The channels between the primary user to SUs and SUs to fusion center are considered to be independent Nakagami-$m$. The proposed fusion rule uses the channel statistics, instead of the instantaneous channel state information, and is based on the Neyman-Pearson criteria. Closed-form solutions for the system-level probability of detection and probability of false alarm are also derived. Furthermore, a closed-form expression for the optimal number of cooperative SUs, needed to minimize the total error rate, is presented. The usefulness of factor graph and sum-product-algorithm models for computing likelihoods, is also discussed to highlight its advantage, in terms of computational cost. The performance of the proposed schemes have been evaluated both by analysis and simulations. Results show that the proposed rules perform well over a wide range of the signal-to-noise ratio.
Outage Probability of Multihop Cooperative Diversity System over Nakagami Fading Channels

Cheng Wei-jun,Zhu Bo-cheng,

电子与信息学报 , 2006,
Abstract: This paper investigates the outage performance of the cooperative diversity systems for multi-hop wireless networks over Nakagami fading channels. Their closed-form expressions of the regenerative outage probability are derived, and the diversity orders are achieved at high Average Signal-to-Noise Ratio (ASNR) in terms of the single relaying node case and multiple relaying nodes case. The theoretical analysis and simulation results show that the cooperative systems can offer the full-route diversity at some given manners, and their diversity order is the sum of the full route diversities, not the sum of all cooperative nodes, however, the diversity order of each route is determined by the smaller one between that of the two hops.
Ergodic Capacity Analysis of Cooperative Amplify-and-Forward Relay Networks Over Rice and Nakagami Fading Channels  [PDF]
Bhuvan Modi,A. Annamalai,O. Olabiyi,R. Chembil Palat
International Journal of Wireless & Mobile Networks , 2012,
Abstract: This article investigates the efficacy of a novel moment generating function (MGF) based analytical framework for calculating the ergodic channel capacities of cooperative dual-hop amplify-and-forward (CAF) relay networks under three distinct source-adaptive transmission policies in Rice and Nakagamim fading environments. The proposed analytical approach relies on a new exponential-type integral representation for the logarithmic function 1 2 20ln ( ) ( ) , 0,x xx e e dxγγ γ∞ = >∫ that facilitates the task of averaging it over the probability density function (PDF) of end-to-end signal-to-noise ratio (SNR) in a myriad of stochastic fading environments. We also resort to a well-known bounding technique to derive closed-form formulas for the upper and lower bounds for the MGF of dual-hop CAF relayed path SNR in Rice and Nakagami-m channels (since exact evaluation of the MGF of half-harmonic mean SNR in Rice fading is known to be very complicated and numerically unstable). These two attributes dramatically reduces the computational complexity of evaluating the ergodic capacities of CAF multi-relay networks with the optimal joint power-and-rate adaptation (when the channel side information is available at both the transmitter and the receiver) and the optimal rate-adaptation with a constant transmit power (whenchannel side information is available at the receiver only) policies.
Performance of MIMO Relay DCSK-CD Systems over Nakagami Fading Channels  [PDF]
Yi Fang,Jing Xu,Lin Wang,Guanrong Chen
Computer Science , 2012,
Abstract: A multi-access multiple-input multiple-output (MIMO) relay differential chaos shift keying cooperative diversity (DCSK-CD) system is proposed in this paper as a comprehensive cooperation scheme, in which the relay and destination both employ multiple antennas to strengthen the robustness against signal fading in a wireless network. It is shown that, with spatial diversity gains, the bit error rate (BER) performance of the proposed system is remarkably better than the conventional DCSK non-cooperation (DCSK-NC) and DCSK cooperative communication (DCSK-CC) systems. Moreover, the exact BER and close-form expressions of the proposed system are derived over Nakagami fading channels through the moment generating function (MGF), which is shown to be highly consistent with the simulation results. Meanwhile, this paper illustrates a trade-off between the performance and the complexity, and provides a threshold for the number of relay antennas keeping the user consumed energy constant. Due to the above-mentioned advantages, the proposed system stands out as a good candidate or alternative for energy-constrained wireless communications based on chaotic modulation, especially for low-power and low-cost wireless personal area networks (WPANs).
Outage performance of cooperative relay network coding in Nakagami-m fading channels

CHEN Gang-zi,YANG Jing,

重庆邮电大学学报(自然科学版) , 2012,
Abstract: This paper analyzes the outrage performance of the traditional coding, Galois field network coding, and complex field network coding based on the factors including Nakagami-m fading channel characteristics, the different power allocation scheme between source and relay, and the relay position between the source and destination nodes. Computer simulation results show that the complex field network coding can improve the outage performance for the network coding.
Performance of Alamouti-Based HARQ for Slow Fading MIMO Channel  [PDF]
Kai-Hua Wang,Chuan-Qing Zhang,Ji-Lin Xu
Information Technology Journal , 2010,
Abstract: Traditional hybrid automatic repeat request (HARQ) protocols extract time diversity in a scalar fading channel. The performance depends critically on the channel variation over retransmissions. The slow fading channel model considered allows no time diversity for the HARQ protocols to exploit. But traditional protocols can not effectively exploit spatial diversity provided by a Multiple Input Multiple Output (MIMO) system. A new Alamouti-based HARQ transmission scheme for a MIMO system in a slowly varying channel is proposed. This new scheme is a combination of the packet combining HARQ and the Alamouti Space-Time Coding (STC). This technique increases the efficiency of HARQ packet transmission by exploiting both the spatial and time diversity of the MIMO channel. It uses the full diversity of Alamouti STC and the added gain of the packet combining scheme to provide reliable communication. The Packet Error Rate (PER) analysis of space-time coded MIMO-HARQ is presented. An n-dimension Pair Wise Error Probability (PWEP) analysis of the optimal Alamouti-based HARQ protocol is derived. Simulation results show that this new scheme outperforms traditional Chase Combining (CC) and reveal the gain of ARQ feedback in space-time coded MIMO systems.
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