Providing a pretty adequate environment condition between the transmission and the receiver for a WSN (wireless sensor network), in which deployed sensor nodes and fusion center, is investigated in the paper. Moreover...Providing a pretty adequate environment condition between the transmission and the receiver for a WSN (wireless sensor network), in which deployed sensor nodes and fusion center, is investigated in the paper. Moreover, an algorithm promotes the energy efficient, increases the accuracy of sensing data and prolongs the lifetime of sensor nodes deployed over an WSNs is proposed. On the basis of adopting sensor management, which involves sensor movement sequences, sensor location arrangement, lifetime requirement for sensor nodes deploy surveillance environment, and the data fusion center, are addressed too. Simulation results from the lifetime performance for sensor nodes defeated by parameters about the environment around the WSNs are illustrated. Parameters aforementioned are including sensing distance, path loss factor, number bits of a transmitted packet, and interference suffering from the path of data transmission etc. Furthermore, the algorithm of sensor location arrangement is modified for the purpose of improving the lifetime performance in WSNs environments. In addition, simulation results show that the proposed algorithm in this paper is not only definitely to improve the energy efficient sufficiently, but the sensing accuracy and the lifetime performance of the sensor nodes are also prolonged significantly.展开更多
In this paper the impact of distinctive structure of antenna with branch correlation for an OFDM (orthogonal frequency division multiplexing)-based system, MC-CDMA (multi-carrier coded-division multiple-access) system...In this paper the impact of distinctive structure of antenna with branch correlation for an OFDM (orthogonal frequency division multiplexing)-based system, MC-CDMA (multi-carrier coded-division multiple-access) system, operating over the frequency selective fading environments is studied. For the reason of accordance with the working environments in the real world applications (urban areas) the correlated-Nakagami-m fading is adopted. Furthermore, the performance evaluation with average BER (bit error rate) formulas of MC-CDMA system with MRC (maximal ratio combining) diversity was derived with an alternative method of the complementary error function. The illustrated results are not only discussing the effect that comes from triangular, linear, and circular antenna array constructions, but the factors of branch correlation are also analyzed. Generally, it is known that the more the received branch number is, the more superior system performance of a multiple-access system will become. It is interesting to contrast to the geometric of the antenna array, that is, the little shape changing of the antenna is, the worse inferior system performance arrive at.展开更多
The evaluation of System Performance of UWB (ultra-wide band) jointing in MC (multi-carrier) signaling in correlated environments is presented in the report. The correlated Nakagami-m statistical distribution for the ...The evaluation of System Performance of UWB (ultra-wide band) jointing in MC (multi-carrier) signaling in correlated environments is presented in the report. The correlated Nakagami-m statistical distribution for the multipath fading model is assumed in this scenario. In fact to establish the model for analyzing in this article is using MC-CDMA (multi-carrier code-division multiple-access) system characterization combined with a UWB scheme. The average BER (bit error rate) is calculated and compared to a special case of previously published results. Studied results from this paper can be implied to approve the system performance for a UWB system combined with a MC-CDMA wireless communication system. It is worth noting that the Nakagami-m distributed fading parameter significantly dominates UWB system performance when it cooperates with MC signaling under a fading environment. Finally, it is worthy of noting that when the SNR (signal-to-noise ratio) at system’s receiver reaches a preset high threshold value, the parameter of power decay ratio effect could be not included.展开更多
In this paper the system performance of an MC-CDMA (multi-carrier coded-division multiple-access) system operating over single-cell with two-tier femtocell environment is analyzed. Consider two-tier scenario is deploy...In this paper the system performance of an MC-CDMA (multi-carrier coded-division multiple-access) system operating over single-cell with two-tier femtocell environment is analyzed. Consider two-tier scenario is deployed with a macrocell site in which is being surrounded several femtocells, which are designed to serve a group of subscribers locate in a small coverage area such as small office, home office or a house. The coverage area is typically up to 100 meters in radius. Mostly, the femtocell is applied to serve indoor subscribers, thus, the Rayleigh fading is adopted to characterize the propagation channel. The technique of TH-MC- CDMA (time-hopped multi-carrier coded-division multiple-access) technique is supposed to transmit each symbol alternatively with fair time (slotting)/frequency (coding) for each user in the hotspots (the area around 0th femtocell). The intensity of signals estimated at a mobile unit located in the second tie, i.e., the femtocell coverage area, is an important issue. The contribution of the paper is mainly to evaluate the system performance with both the BER (bit error rate) and OP (outage probability) according to the most important parameters, for example, the activating user number, the hopping number provided by TH-MC-CDMA system and the subcarrier number. Furthermore, the discussion of interference avoidance is also discussed with non-analytically.展开更多
A high efficiency full-bridge converter is investigated and implemented in this paper. The measured data result from the other converter implemented by IC UCC3895 is to compare with that of the previous converter. Thi...A high efficiency full-bridge converter is investigated and implemented in this paper. The measured data result from the other converter implemented by IC UCC3895 is to compare with that of the previous converter. This full-bridge converter proposed and implemented converter can obtain about 96% power efficiency in conversion procedure when compared with that of 90%, which were ever published by the conventional techniques. Apart from, the L-C resonance circuits were developed and embedded into the popular PWM (pulse width modulation) power converter, which is referred as the soft-switching, so as to down sizing the volume of the IC which can totally reduces the power losses caused in the duration of a semi-con- ductor switching.展开更多
An algorithm for enhancing the throughput of CAS (Cooperation-Aware Scheme) over a WSN (wireless sensor network) is presented in this article. The WSNs are classified as a task-oriented framework due to the fact that ...An algorithm for enhancing the throughput of CAS (Cooperation-Aware Scheme) over a WSN (wireless sensor network) is presented in this article. The WSNs are classified as a task-oriented framework due to the fact that the power supply, memory and computing power of wireless sensor nodes are greatly hampered in WSNs. This study?focused on exploring problems caused by traffic congestion on the WSNs with a large amount of flow, such as packet loss, bandwidth reduction, and waste of energy on the sensor nodes. On the other hand, the proposed CAS is a cooperative strong node mechanism in which a threshold is preset in order to determine whether the node traffic is over or not. The privilege of corresponding sensor nodes is upgraded when the load exceeds the threshold. Therefore, the sensor node can command its child nodes to change the transmission path for distributing the traffic effectively. Moreover, once the traffic is over the overall network flow threshold, it is necessary to add the other new sensor nodes into the network for relieving the traffic.展开更多
A simplified three-dimension(3D) fading channel model deployed in a multi-input multi-output(MIMO) beamforming system is explored in this article.Both angle of arrival(AoA) and angle of departure(Ao D) which i...A simplified three-dimension(3D) fading channel model deployed in a multi-input multi-output(MIMO) beamforming system is explored in this article.Both angle of arrival(AoA) and angle of departure(Ao D) which impact the overall system performance are examined. The numerical results are given for validating the accuracy of the theoretical derived formulas. Furthermore, the performances of the model with different number of transmitters and receivers are studied and compared. The increment in Ao A parameters definitely generates the impact of the system performance when the consideration of simplified 3D channels.展开更多
The dominate factors caused by reasons of losing the orthogonality in fading channel including FBC (fading branch correlation), CFO (carrier frequency offset), and even the CPN (carrier phase noise) are novel discussi...The dominate factors caused by reasons of losing the orthogonality in fading channel including FBC (fading branch correlation), CFO (carrier frequency offset), and even the CPN (carrier phase noise) are novel discussion in this letter. The first one factor causes the ISI (inter-symbol interference), and, however, the latter two will lead to the phenomenon of CPE (common phase error) and ICI (inter-carrier interference). On the other hand, they will lead to the loss of orthogonality for the radio system with multi-carrier modulating schemes, i.e., both them mainly deteriorate a wireless communication system. Eventually, in this letter not only the analytical expressions are derived, but a three dimension numerical results from the analysis involve the three parameters also illustrated is.展开更多
文摘Providing a pretty adequate environment condition between the transmission and the receiver for a WSN (wireless sensor network), in which deployed sensor nodes and fusion center, is investigated in the paper. Moreover, an algorithm promotes the energy efficient, increases the accuracy of sensing data and prolongs the lifetime of sensor nodes deployed over an WSNs is proposed. On the basis of adopting sensor management, which involves sensor movement sequences, sensor location arrangement, lifetime requirement for sensor nodes deploy surveillance environment, and the data fusion center, are addressed too. Simulation results from the lifetime performance for sensor nodes defeated by parameters about the environment around the WSNs are illustrated. Parameters aforementioned are including sensing distance, path loss factor, number bits of a transmitted packet, and interference suffering from the path of data transmission etc. Furthermore, the algorithm of sensor location arrangement is modified for the purpose of improving the lifetime performance in WSNs environments. In addition, simulation results show that the proposed algorithm in this paper is not only definitely to improve the energy efficient sufficiently, but the sensing accuracy and the lifetime performance of the sensor nodes are also prolonged significantly.
文摘In this paper the impact of distinctive structure of antenna with branch correlation for an OFDM (orthogonal frequency division multiplexing)-based system, MC-CDMA (multi-carrier coded-division multiple-access) system, operating over the frequency selective fading environments is studied. For the reason of accordance with the working environments in the real world applications (urban areas) the correlated-Nakagami-m fading is adopted. Furthermore, the performance evaluation with average BER (bit error rate) formulas of MC-CDMA system with MRC (maximal ratio combining) diversity was derived with an alternative method of the complementary error function. The illustrated results are not only discussing the effect that comes from triangular, linear, and circular antenna array constructions, but the factors of branch correlation are also analyzed. Generally, it is known that the more the received branch number is, the more superior system performance of a multiple-access system will become. It is interesting to contrast to the geometric of the antenna array, that is, the little shape changing of the antenna is, the worse inferior system performance arrive at.
文摘The evaluation of System Performance of UWB (ultra-wide band) jointing in MC (multi-carrier) signaling in correlated environments is presented in the report. The correlated Nakagami-m statistical distribution for the multipath fading model is assumed in this scenario. In fact to establish the model for analyzing in this article is using MC-CDMA (multi-carrier code-division multiple-access) system characterization combined with a UWB scheme. The average BER (bit error rate) is calculated and compared to a special case of previously published results. Studied results from this paper can be implied to approve the system performance for a UWB system combined with a MC-CDMA wireless communication system. It is worth noting that the Nakagami-m distributed fading parameter significantly dominates UWB system performance when it cooperates with MC signaling under a fading environment. Finally, it is worthy of noting that when the SNR (signal-to-noise ratio) at system’s receiver reaches a preset high threshold value, the parameter of power decay ratio effect could be not included.
文摘In this paper the system performance of an MC-CDMA (multi-carrier coded-division multiple-access) system operating over single-cell with two-tier femtocell environment is analyzed. Consider two-tier scenario is deployed with a macrocell site in which is being surrounded several femtocells, which are designed to serve a group of subscribers locate in a small coverage area such as small office, home office or a house. The coverage area is typically up to 100 meters in radius. Mostly, the femtocell is applied to serve indoor subscribers, thus, the Rayleigh fading is adopted to characterize the propagation channel. The technique of TH-MC- CDMA (time-hopped multi-carrier coded-division multiple-access) technique is supposed to transmit each symbol alternatively with fair time (slotting)/frequency (coding) for each user in the hotspots (the area around 0th femtocell). The intensity of signals estimated at a mobile unit located in the second tie, i.e., the femtocell coverage area, is an important issue. The contribution of the paper is mainly to evaluate the system performance with both the BER (bit error rate) and OP (outage probability) according to the most important parameters, for example, the activating user number, the hopping number provided by TH-MC-CDMA system and the subcarrier number. Furthermore, the discussion of interference avoidance is also discussed with non-analytically.
文摘A high efficiency full-bridge converter is investigated and implemented in this paper. The measured data result from the other converter implemented by IC UCC3895 is to compare with that of the previous converter. This full-bridge converter proposed and implemented converter can obtain about 96% power efficiency in conversion procedure when compared with that of 90%, which were ever published by the conventional techniques. Apart from, the L-C resonance circuits were developed and embedded into the popular PWM (pulse width modulation) power converter, which is referred as the soft-switching, so as to down sizing the volume of the IC which can totally reduces the power losses caused in the duration of a semi-con- ductor switching.
文摘An algorithm for enhancing the throughput of CAS (Cooperation-Aware Scheme) over a WSN (wireless sensor network) is presented in this article. The WSNs are classified as a task-oriented framework due to the fact that the power supply, memory and computing power of wireless sensor nodes are greatly hampered in WSNs. This study?focused on exploring problems caused by traffic congestion on the WSNs with a large amount of flow, such as packet loss, bandwidth reduction, and waste of energy on the sensor nodes. On the other hand, the proposed CAS is a cooperative strong node mechanism in which a threshold is preset in order to determine whether the node traffic is over or not. The privilege of corresponding sensor nodes is upgraded when the load exceeds the threshold. Therefore, the sensor node can command its child nodes to change the transmission path for distributing the traffic effectively. Moreover, once the traffic is over the overall network flow threshold, it is necessary to add the other new sensor nodes into the network for relieving the traffic.
文摘A simplified three-dimension(3D) fading channel model deployed in a multi-input multi-output(MIMO) beamforming system is explored in this article.Both angle of arrival(AoA) and angle of departure(Ao D) which impact the overall system performance are examined. The numerical results are given for validating the accuracy of the theoretical derived formulas. Furthermore, the performances of the model with different number of transmitters and receivers are studied and compared. The increment in Ao A parameters definitely generates the impact of the system performance when the consideration of simplified 3D channels.
文摘The dominate factors caused by reasons of losing the orthogonality in fading channel including FBC (fading branch correlation), CFO (carrier frequency offset), and even the CPN (carrier phase noise) are novel discussion in this letter. The first one factor causes the ISI (inter-symbol interference), and, however, the latter two will lead to the phenomenon of CPE (common phase error) and ICI (inter-carrier interference). On the other hand, they will lead to the loss of orthogonality for the radio system with multi-carrier modulating schemes, i.e., both them mainly deteriorate a wireless communication system. Eventually, in this letter not only the analytical expressions are derived, but a three dimension numerical results from the analysis involve the three parameters also illustrated is.