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CDMA手机的机卡分离 总被引:1,自引:0,他引:1
本文介绍了手机卡分离的现状和意义,详细说明了CDMA手机机卡分离的发展历程及其技术规范,最后预测了它的发展前景。 相似文献
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给出了一个基于JPEG2000算法的红外图像压缩解压缩系统的设计方案。该系统使用专用的硬件压缩芯片ADV202以及ADV7179、ADV7189和FPGA内嵌的NiosII软核处理器,解决了直接采用FPGA+DSP设计复杂、开发周期长的缺点。NiosII软核处理器通过IIC总线对ADV202、ADV7189的控制实现图像数据的A/D转换和图像压缩,对ADV202、ADV7179的控制实现图像的解压缩和D/A转换。与此同时采用抽场补场的方式实现图像压缩和传输速率的要求,并且通过改变抽场参数可以实现传输速率的改变。实验表明文中的设计方案达到了系统要求的各项技术指标。 相似文献
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To improve the detection performance of sensing users for primary users in the cognitive radio, an optimal cooperative detection algorithm for many sensing users is proposed. In this paper, optimal decision thresholds of each sensing user are discussed. Theoretical analysis and simulation results indicate that the detection probability of optimal decision threshold rules is better than that of determined threshold rules when the false alarm of the fusion center is constant. The proposed optimal cooperative detection algorithm improves the detection performance of primary users as the attendees grow. The 2 dB gain of detection probability can be obtained when a new sensing user joins in, and there is a 17 dB improvement when the accumulation number increases from 1 to 50. 相似文献
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To deal with hidden nodes in ad hoc network, we take throughput as the metric to evaluate the performance of network. Firstly, we modeled the MAC layer of ad hoc network based on 802.11 DCF without the existence of hidden nodes. By means of the proposed model, we evaluated the throughput performance of DCF in multi-hop wireless networks. Secondly, we performed simulations to validate this model. The outcome of comparison is that there exists much difference in throughput between the model and the simulation. For reducing this difference, we modified the model by involving hidden nodes under the condition that the AODV route protocol was chosen, and analytically analyzed the influence of hidden nodes on theoretical throughput. At last, we validated the accuracy of this model by comparing the analytical results with simulation results. 相似文献
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早在1985年,国际电联(ITU)就提出了第三代移动通信的概念,当时称为未来公用陆地移动通信系统(FPLMTS),1996年改为IMT2000。1998年10月,第三代伙伴计划(3GPP)出台。1999年1月,3GPP2正式成立,该组织包括美国的TIA、中国的 相似文献
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