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The growing demand of high data rates requires much energy consumption. For this, in this paper we examine energy efficiency (EE) through total energy expenditure per bit characterization when the joint coupling between Modulation and Coding Scheme (MCS) related to the physical layer and Selective Repeat (SR) truncated Hybrid Automatic Repeat reQuest (HARQ) type I protocol of data link layer is performed into Multiband Orthogonal Frequency Division Multiplexing (MB-OFDM) Ultra-Wideband (UWB) system. The optimization is based on total energy expenditure per bit diminishing constrained by MCS rate and Packet Error Rate (PER). We propose an algorithm to identify the optimal MCS rate basing on dichotomy policy. Thus, analytical analysis highlights a closed-form expression of the optimal MCS rate allowing energy per bit minimization. In addition, in measuring the energy consumption per useful information the hardware components of MB-OFDM UWB (MB-UWB) crosslayer structure are considered. Further, the analytical framework is validated through computer results which reveal the effectiveness of our method in terms of energy saving.

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Energy Efficiency (EE) has become one of the main challenges for the development of wireless communication systems. Thus, many researchers are investigating new solutions to save power. For this reason, in this paper we apply a method based on modulation and coding scheme (MCS) for multiband orthogonal frequency division multiplexing (MB-OFDM) ultra wideband (UWB) systems. The MCS scheme is a powerful method known by its ability to improve the spectral efficiency. Our goal in this paper is to investigate the performance of MCS mechanism to diminish the transmitted power under some assumptions. Computer results show the throughput behavior in function of signal to noise ratio (SNR) for different selection of modulation and coding rate. Then, we draw the plot of bit error rate (BER) versus SNR and versus the energy per bit to noise power spectral density ratio (E b /N o ).

Background. Due to the great increase of accident into roads, vehicular communication becomes the focus of many researchers. Therefore vehicular communication is becoming an active topic of search. That's why safety driving is the main concern of many researcher to mitigate congestion problems specifically following urban scenario. Due to the requirement of URLLC, we investigate in this paper the importance of power diminishing. In fact, power minimization is an interesting metric due to the requirement of high data rates.Objective. The aim of the paper is to investigate power allocation into LTE-V system following a decentralized scenario.Methods. The idea is to consider a platoon with a set of vehicles interacting together for network resources without the help of ENodeB. Power consumption minimization is a promising solution for interference diminishing since vehicles communicate according to a decentralized way. In this regard the theoretical analysis is based on applying stackelberg game policy for power control in the way to minimize interference.Results. We conclude that stackelberg game policy is a powerful tool for interference and power consumption management. Computer results highlight the efficiency of SK game for power allocation into a decentralized scenario.Conclusions. Vehicular Autonomous communication attracted the attention of many researchers according to increasing number of congestion together with traffic problems. In addition, to ensure better safety we adopt platooning scenario which enables mitigations of many problems such as collisions, congestion. Inter-car communication is an interesting topic of search to ensure safety into-roads. In addition, platooning has the potential to ensure safety with low energy consumption specifically towards urban traffic. In addition, LTE-V is a heuristic solution for vehicular communication where the connectivity is performed in a decentralized context without the requirement of the ENodeB.

International audienceIn this contribution, we study the performance analysis of the Multiband Orthogonal Frequency Division Multiplexing Ultra Wide Band (MBOFDM UWB) high data rate system. The major problem of the MBOFDM UWB high data rate system is the cohabitation of more than three piconets sharing the same group of subbands over the same channel. As an alternative way to enhance the spectral efficiency of MBOFDM UWB system, the Channel Division Multiple Access (ChDMA) could be employed to explore the high diversity of UWB channels. The idea behind the ChDMA is to assimilate the channel impulse response (CIR) related to each user as a CDMA code signature. This approach increases the performance of the system by guarantying simultaneous access. Simulations are run over UWB indoor channel model and it is shown that MBOFDM UWB ChDMA outperforms MBOFDM UWB in respect of the metric of capacity. The simulations are performed through Minimum Mean Square Error receivers (MMSE) and the performance is evaluated based on the tradeoff between spectral efficiency (bit/s/Hz) and the ratio of number of users and "code" length. Numerical results show the advantage of ChDMA approach to enhance spectral efficiency of MBOFDM UWB high data rate system based on the accommodation of simultaneous operating piconets (SOPs)

International audienceIn this contribution we study the challenging issue of WiMedia solution which the ability to support high data rate applications but is limited to three piconets simultaneously communicating in the same area. For this reason we analyze the suitability of Channel Division Multiple Access (ChDMA) approach for Multiband Orthogonal Frequency Division Multiplexing (MBOFDM) Ultra Wide Band (UWB) (MB-UWB) system over IEEE 802.15.3a (UWB) channel model. ChDMA approach exploits the characteristics of MB-UWB system to separate the piconets. Each piconet employs its own Channel Frequency Response (CFR) as a signature code which introduces diversity. We have presented analytical analysis in terms of spectral efficiency (bits/s/Hz) assuming that the receiver knows the channel. Numerical analysis is run over IEEE 802.15.3a high data rate channel justified the importance of ChDMA solution to improve the spectral efficiency of MB-UWB system. Then, performance evaluation is investigated when minimum mean square error (MMSE) and matched filter (MF) receiver is applied. Simulations results show the importance of MMSE receiver to improve the performance of MB-UWB ChDMA system