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1.
In forensic investigations,it is vital that the authenticity of digital evidence should be ensured. In addition,technical means should be provided to ensure that digital evidence collected cannot be misused for the purpose of perjury. In this paper,we present a method to ensure both authenticity and non-misuse of data extracted from wireless mobile devices. In the method,the device ID and a timestamp become a part of the original data and the Hash function is used to bind the data together. Encryption is applied to the data,which includes the digital evidence,the device ID and the timestamp. Both symmetric and asymmetric encryption systems are employed in the proposed method where a random session key is used to encrypt the data while the public key of the forensic server is used to encrypt the session key to ensure security and efficiency. With the several security mechanisms that we show are supported or can be implemented in wireless mobile devices such as the Android,we can ensure the authenticity and non-misuse of data evidence in digital forensics.  相似文献   

2.
Long Term Evolution( LTE) has been proposed as an advanced wireless radio access technology to provide higher peak data rates and better spectral utilization efficiency,but the classical scheduling and resource allocation algorithms cannot optimally enhance the system performance due to high computational complexity. In this paper,a re-configurable dual mode delay-aware( CDD) scheduling and resource allocation algorithm is proposed to achieve the joint consideration of scheduling pattern,scheduling priority and quantity of scheduled data. In this study,dual-mode scheduling mechanism is associated with three configurable parameters and the CDD algorithm is involved to guarantee queuing delay with low loss of resource utilization and fairness.The computational cost of the scheduling and resource allocation algorithm is significantly reduced by efficiently utilizing Qo S Class Identifier( QCI) and Channel Quality Indicator( CQI) defined by LTE standards. The simulation results based on different application scenarios also represent the computation cost and complexity of scheduling algorithm along with the improved system throughput.  相似文献   

3.
This paper proposes a new scheduling algorithm for allocating the LTE radio resource, Priority Semi-Persisting Scheduling(PrSPS). PrSPS calculates the priority of the user equipment using the user grade, PRBs needed, average channel quality and average transmission rate. Adopting this priority method in semi-persisting scheduling mechanism can avoid the competition between resource scheduling signalling and voice date, improve the radio resource utilization and scheduling efficiency, increase the user capacity of VoLTE and improve satisfaction of VoLTE users. Using the NS-3 simulation platform, the paper evaluates the performance of PrSPS.  相似文献   

4.
一种多用户MIMO/OFDMA系统的资源分配和调度方案   总被引:3,自引:2,他引:1  
针对下行多用户多入多出/正交频分复用系统,提出了一种适合多业务类型的资源分配和调
度算法. 综合考虑了不同业务类型的服务质量需求,根据用户的信道条件、吞吐量和队列状
态确定调度优先级;结合用户信道的空间相关性进行用户选择、功率分配和比特加载. 通过
充分利用空、时、频多用户分集增益,在保证实时业务最小时延要求和非实时业务最小速率
要求的同时,最大化系统的吞吐量. 仿真结果说明,所提算法在系统吞吐量、丢包率及最
小速率满足率方面得到了改善.  相似文献   

5.
An improved spectrum-efficient and fair resource scheduling algorithm for multimedia broadcast multicast service (MBMS) in long term evolution (LTE) systems is proposed in this paper. By jointly considering the channel conditions of all the users, the average packet loss rate, and the fairness of users in the MBMS group, the transmission data rate of the MBMS group is first selected according to the link adaptation and the average packet loss rate of users. Then, the resource blocks are allocated to MBMS groups according to the scheduling priority. Such a resource scheduling algorithm further balances the system throughput and user fairness. Theoretical analysis and simulation results show that the proposed algorithm can achieve a good tradeoff between system throughput and user fairness in comparison with traditional scheduling algorithms.  相似文献   

6.
提出了一种用于正交频分多址通信系统下行链路的多小区自适应资源分配算法(MARA)。为了降低系统复杂度,将子信道分配和功率分配分开实现,在小区内部进行动态子信道分配,并以单小区子信道分配结果为基础在相邻小区同频用户中进行功率分配。将非合作博弈论引入到多小区功率分配中,给出了基于代价函数的多小区分布式功率分配算法。通过协调相邻小区间同频子信道的发送功率,抑制小区间干扰,提高无线资源利用率。仿真结果表明,与已有算法相比,本文提出的算法可以提高系统吞吐量。  相似文献   

7.
针对功率受限的多用户OFDMA系统,提出了一种简化的子载波和功率分配算法,此算法在最大化系统容量的同时兼顾了用户间的公平性。算法首先依据当前的信道状况计算出各用户所需的载波数量,并分配子载波,然后以注水算法对各载波上的功率进行分配。仿真结果表明,以此算法对OFDMA的系统资源进行分配可显著提高系统的多项性能。  相似文献   

8.
一种基于网格距离的资源调度   总被引:1,自引:0,他引:1  
在网格资源调度中,当任务选择与自己距离较近、可用带宽较大的资源时,调度体现更好的特性。文章就距离、可用带宽并结合资源的使用费用,提出了网格距离的概念,实现网格资源选择中对上述因素的约束。定义了网格资源和应用的模型,在该模型上完成网格距离的计算,提出了资源选择算法。仿真实验表明,调度在通信开销、稳定性、任务完成时间以及任务执行的失败率等方面都得到了改善,同时促进整个网格系统资源交易的吞吐量。  相似文献   

9.
多播系统中基于多用户分集的资源分配   总被引:1,自引:1,他引:0  
针对无线多播系统中传输速率受限于多播组中最差用户信道容量的问题,提出一种组内资源分配算法.在考虑用户之间不同速率需求的前提下,对多播组内用户进行子载波分配和功率分配,来最大化多播系统归一化速率.子载波分配算法利用每个子载波上多播用户之间的多用户分集,将子载波分配给该子载波上性能较好的多个用户.功率分配算法采用基于梯度的功率分配方式对各子载波上所分配的功率做局部优化,进一步提高多播系统的传输速率.仿真结果表明,与传统多播组内资源分配方案相比,显著提升多播系统的归一化速率.  相似文献   

10.
提出了一种正交频分多址(OFDMA)分布式天线系统下的子载波和功率分配算法,该算法在满足用户比例速率要求、天线独立功率限制要求下,使系统的总等效容量最大化. 通过把多维天线下的资源分配问题分解为独立单天线下的子优化问题,有效地降低了算法复杂度. 仿真结果表明,该分配算法能较好地满足比例公平的速率要求;相对于集中式天线系统和固定FDMA分配方式,均有较大的容量提升.  相似文献   

11.
为改善多业务LTE下行系统的吞吐量和公平性并满足用户对多业务的需求,提出一种基于遗传算法的资源分配算法。该算法以遗传算法为基础,建立以适应度函数值之和最大化为目的的优化目标,根据用户业务的服务质量需求和信道状态信息设计适应度函数,经过选择、交叉、变异等操作,得到相对最优资源分配方案。仿真结果表明,与传统算法相比,该算法满足多种业务的服务质量需求,增加系统的公平性,对实时业务提供较小的时延,对尽力而为业务提供更大的吞吐量。  相似文献   

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