Haci Ilhan

Cooperative Diversity for Intervehicular Communication: Performance Analysis and Optimization

Although there has been a growing literature on cooperative diversity, the current literature is mainly limited to the Rayleigh fading channel model, which typically assumes a wireless communication scenario with a stationary base station antenna above rooftop level and a mobile station at street level. In this paper, we investigate cooperative diversity for intervehicular communication based on cascaded Nakagami fading. This channel model provides a realistic description of an intervehicular channel where two or more independent Nakagami fading processes are assumed to be generated by independent groups of scatterers around the two mobile terminals. We investigate the performance of amplify-and-forward relaying for an intervehicular cooperative scheme assisted by either a roadside access point or another vehicle that acts as a relay. Our diversity analysis reveals that the cooperative scheme is able to extract the full distributed spatial diversity. We further formulate a power-allocation problem for the considered scheme to optimize the power allocated to the broadcasting and relaying phases. Performance gains up to 3 dB are obtained through optimum power allocation, depending on the relay location.

Cooperative Diversity for Relay-Assisted Inter-Vehicular Communication

Although there has been a growing literature on cooperative diversity, the current literature is mainly limited to Rayleigh fading channel model which typically assumes a wireless communication scenario with a stationary base station antenna above roof-top level and a mobile station at street level. In this paper, we investigate cooperative diversity for inter-vehicular communication based on cascaded Rayleigh fading. This channel model provides a realistic description of inter-vehicular channel where two or more independent Rayleigh fading processes are assumed to be generated by independent groups of scatterers around the two mobile terminals. We investigate the performance of amplify-and-forward relaying for an inter-vehicular cooperative scheme assisted by a road-side access point which acts as a relay. Our diversity analysis reveals that the cooperative scheme is able to extract the full distributed spatial diversity. We further formulate a power allocation problem for the considered scheme to optimize the power allocated to broadcasting and relaying phases. Performance gains up to 2.8 dB are observed through optimum power allocation depending on the relay location.

Performance Analysis of Two-Way AF Relaying Systems Over Cascaded Nakagami-

In this letter, we investigate the error rate performance of two-way amplify-and-forward (AF) relaying communication system over independently but not necessarily identically distributed (i.n.i.d.) cascaded Nakagami- fading channels. We have derived a closed-form expressions of cumulative distribution function (CDF) and moment generating function (MGF) for considering system. By using these expressions, we analyse the performance of two-way AF relaying system in terms of outage probability and symbol error rate (SER). Numerical and simulation results show the validity of the proposed mathematical analysis and point out the confirmation of the analytical results.

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Abstract In this paper, we investigate a dual-hop decode-and-forward (DF) relaying vehicular system in the presence of co-channel interference, in which source, relay and destination terminals are composed of vehicles and interferers are stationary. Independently but not necessarily identically distributed (i.n.i.d.) cascaded Nakagami-m fading is adopted to characterize the vehicle-to-vehicle channel. Novel closed-form expressions are derived for cumulative distribution function (CDF) of end-to-end signal-to-interference-plus-noise-ratio at the relay and the destination. By using CDF expressions, we have analyzed the performance of dual-hop DF relaying vehicular systems in terms of outage probability and average symbol error probability. Then, we have calculated the upper bounds of outage probability and symbol error probability expressions for high signal-to-noise ratio. Lastly, the effect of relay geometry on system performance has been examined. The proposed mathematical analyses have been verified through the Monte-Carlo simulations.

Fading Channels

In this study, the authors investigate the error rate performance of amplify-and-forward relaying over N*Nakagami fading channels. This is a recently introduced channel model that involves the product of N Nakagami-m-distributed random variables. Employing the moment generating function approach, the authors derive symbol error rate expressions for a single-relay system under instantaneous power scaling (IPS) and average power scaling (APS) factors at the relay node, that is, variable and fixed gains. The results achieved by the authors demonstrate that the achievable diversity order is a function of Nakagami fading parameter (m) and degree of cascading (N). An identical diversity order is obtained under both scaling factors when the relay is close to the destination. When the relay is close to the source, IPS becomes advantageous over APS. Monte–Carlo simulations are further provided to confirm the analytical results.

Performance Analysis of Cooperative Vehicular Systems with Co-channel Interference Over Cascaded Nakagami-m Fading Channels

Cooperative communication techniques promise the advantages of MIMO (multi-input multi-output) communications for wireless scenarios with single-antenna terminals. In this paper, we investigate the performance of a vehicle-to-vehicle cooperative scheme where another vehicle in the vicinity of the source vehicle acts as a relay. The underlying source-to-relay, relay-to-destination, and source-to-destination links are modeled as cascaded (double) Rayleigh fading. This statistical model provides a realistic description of inter-vehicular channel where two or more independent Rayleigh fading processes are assumed to be generated by independent groups of scatterers around the two mobile terminals. We derive a pairwise error probability (PEP) expression for the inter-vehicular cooperative scheme under consideration and show that the full distributed spatial diversity is extracted. Based on the derived PEP expressions, we obtain union bounds on the bit error rate performance which are then minimized to optimally allocate power between broadcasting and relaying phases. Optimum power allocation brings performance gains up to 3dB depending on the relay location and deployed modulation scheme.

Moment generating function-based performance evaluation of amplify-andforward relaying in n¿nakagami fading channels

In this paper, we present a design of two-way communication system with relay selection in two-way cooperative system over cascaded Nakagami-

Relay Selection in Two-Way Cooperative Systems

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