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Opportunistic packet scheduling optimization problem in orthogonal frequency division multiplexing (OFDM) distributed antenna systems (DAS) is investigated by this paper. Physical-layer channel state information (CSI) and wireless links' requirements for bit error rate are taken into account during problem formulation. The optimization aim is to minimize packet loss rate (PLR) subject to limited wireless...
Power offset is zero-order term in the SNR-capacity curve. In this contribution, approximate analysis of power offset is used to describe single-user two transmit multiple receive MIMO system with uniform linear antenna arrays of fixed length by fitting determinant curve of tri-diagonal Toeplitz matrix. The simulation results show that approximation of power offset is precise in the position of extreme...
Interleave-division multiple access (IDMA) has recently been introduced in relay systems in order to exploit diversity gain. Combining with delay-diversity (DD), the relay scheme based on IDMA can support multiple users. In this paper, we extend the DD-IDMA relay scheme to MIMO relay networks employing spatial multiplexing. We also develop a symbol-by-symbol iterative detection method at the destination...
MBMS is an efficient means to provide multimedia services by sharing common radio channels among a group of users. This paper presents performance evaluation of MBMS in LTE framework by a simulator set up according to 3GPP standard. A general comparison is first made among point-topoint (p-t-p), point-to-multipoint (p-t-m) and single frequency network (SFN), which shows that p-t-m with feedback is...
In wide band wireless communication systems, apropos scheduling and link adaptation are significant to meet the high spectrum efficiency and high rate data transmission demand. Channel quality indication (CQI) feedback is crucial for the system to obtain accurate information used in scheduling. But with the increasing of user number and bandwidth, the CQI feedback will bring intolerable overhead....
Multimedia Broadcast/Multicast Service (MBMS) based on point-to-multipoint (p-t-m) radio transmission was introduced by 3GPP to deliver broadcast service to a group of user equipments (UEs) in a cellular system. As a broadcast system with uplink feedback, its performance is limited by UEs in poor connections. To utilize the limited radio resource more efficiently, a simple but effective mechanism...
In spite of the significant performance gain that multiple-input multiple-output (MIMO) transmission can provide in wireless communication, the use of MIMO in realistic systems will lead to large control signaling overhead. Performance comparison of different transmission schemes should consider the control channel (CC) constraints. In this paper, we first build the model of CC for downlink MIMO transmission,...
End-to-end performance of multihop wireless communication systems with non-regenerative channel state information (CSI)-assisted relays operating over independent not necessarily identically Weibull fading channels is presented. With the aid of the inequality between harmonic and geometric means, the end-to-end signal-to-noise ratio (SNR) is bounded. By considering the product of rational powers of...
We present the end-to-end performance of dual-hop wireless communication systems with non-regenerative fixed gain relays operating over independent not necessarily identically generalized-K (KG) fading channels. New closed-form expressions are derived for the moments of the end-to-end signal-to-noise ratio (SNR), while the corresponding moment- generating function (MGF) is accurately approximated...
The ambient calculus can depict the essence of mobile computing mobility on the basic level, but it canpsilat depict the collaboration character of collaboration computing. In order to depict the collaboration character of mobile collaboration while depicting mobility of it, a novel model named EACM, an extended ambient calculus model oriented mobile collaboration, was provided based on ambient calculus...
Aiming at the automatic composition issue of services in mobile collaboration platform, an agent-based automation service composition algorithm was proposed in this paper. Firstly, the status of service composition and agent technology was analyzed in depth. Then, transfer the semantic service to the equivalence action of agent plan. Based on it, the semantic service automation composition was carried...
According to the current problems of electronic measure facing, this paper elaborates the necessity of network to turn more intellectualized of oscilloscope technology, combined with embedded technology put forward that Embedded made oscilloscopes and the combination of a new type of intelligent embedded digital Phosphor oscilloscope structure, expatiates the structure of software, cut of operating...
Multimedia Broadcast/Multicast Service (MBMS) provides efficient solution for multimedia broadcasting services by distributing resources among a group of subscribers. Different from previous broadcasting services, MBMS subscribers will send feedback information which can be used to improve system performance by adapting resource allocation to channel state. In this paper in LTE frameworks we propose...
In this paper, a frequency-modulated-continuous-wave (FMCW) ground penetrating radar (GPR) is developed and used to measure the thickness of concrete/asphalt layers of highways/airports. If the thickness of the layer is thin, measurement may be impossible using traditional DFT method since the frequencies of reflected waves are very close and the week waves reflected from underground layers will be...
In radio resource management of multimedia broadcast/multicast service (MBMS), user equipment (UE) feedback can be used by evolved Node B (eNB) to improve the radio spectral efficiency. As UE feedback is costly we here suggest schemes to reduce the uplink feedback while maintaining the spectral efficiency. For the 3 schemes analyzed in this paper we utilize the special characteristic of a broadcast...
Constellation labeling is an one-to-one mapping relationship associating 0–1 bit sequences and signal points. Different constellation labeling results in different bit error rate (BER) performance. Some works have certified that the Binary Reflected Gray Code for M-PAM, M-PSK and M-QAM can give the lowest possible average BER. But there are few works considering about the best labeling for other specially...
In this paper, we develop an analytical model based on Markov chains for studying the handoff performance of the Integrated Cellular Ad hoc Relaying (iCAR) system. We verify the analytical model via simulations. Then, based on the model, we analyze the call blocking and dropping probabilities of iCAR system with and without call admission control (CAC) schemes. The fractional guard channel scheme...
Based on the application of active networks in congestion control, this paper introduces the traditional congestion control policy and analyses their principles and feasibilities. Active networks congestion control policy introduces the active detection and the passive notification mechanism, the random early detect (RED) queue management and the load balance technology based on the traditional congestion...
A novel network-coding-based retransmission mechanism using chase combining mechanism for broadcast flows is presented. An information-theoretic performance bound is also developed to explain and predict the coding gains of the chase combining (CC) in network coding broadcast scheme using random coding bounding techniques. The core idea is to recover packets for individual receiver simultaneously...
Conventional heterogeneous-traffic scheduling schemes utilize zero-delay constraint for real-time services, which aims to minimize the average packet delay among real-time users. However, in light or moderate load networks this strategy is unnecessary and leads to low data throughput for non-real-time users. In this paper, we propose a heuristic scheduling scheme to solve this problem. The scheme...
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