A new auto-reference(AR)transmit-receive scheme and a corresponding group decision algorithm on the generalized likelihood ratio testing(GLRT)principle is proposed in this paper to overcome the drawbacks of the power ...A new auto-reference(AR)transmit-receive scheme and a corresponding group decision algorithm on the generalized likelihood ratio testing(GLRT)principle is proposed in this paper to overcome the drawbacks of the power inefficiency and the high noise vulnerability in transmitted-reference(TR)ultra-wideband(UWB)systems.A partly overlapped detection window structure is introduced in which the decided data frames are regarded as the reference signal so that energy and time resources in the reference frame are saved and full-rate data transmission is achieved.Differential coding was utilized to solve the error propagation problem introduced by the overlapped detection windows.The group decision algorithm on the GLRT principle was utilized to estimate the correlation template through all data frames in detection windows and could offer better noise suppression.Simulation results reveal that the AR scheme with its decision algorithm outperforms the conventional and other modified TR schemes in generalized signal-to-noise ratio(SNR).展开更多
针对时间反演(time reversal,TR)技术无法较好地解决聚焦区内非法用户窃听的问题,提出了一种TR技术联合接收端人工噪声的物理层安全传输方案。首先,利用时间反演技术的空时聚焦性提高合法用户接收端的信噪比(signal to noise ratio,SNR...针对时间反演(time reversal,TR)技术无法较好地解决聚焦区内非法用户窃听的问题,提出了一种TR技术联合接收端人工噪声的物理层安全传输方案。首先,利用时间反演技术的空时聚焦性提高合法用户接收端的信噪比(signal to noise ratio,SNR)。其次,通过在接收端加入人工噪声来干扰非法用户对合法用户保密信息的窃听,以聚焦区内外系统安全性能为基础,推导出保密信干噪比(signal to interference plus noise ratio,SINR)、可达保密速率和误码率(bit error rate,BER)的解析表达式。最后,通过仿真分析证明了所提方案能提高系统的SINR和可达保密速率,同时还能降低合法用户的BER,使系统拥有更好的安全性能。展开更多
简要介绍了高度表测量系统用射频前端收发组件的设计方案。详细阐述了主要功能单元电路和重要技术指标的设计考虑。该射频前端达到的指标为:输出发射功率大于16 W,输出功率全温稳定性小于0.1 d B/10℃,收发隔离大于112 d Bc,端口泄漏小...简要介绍了高度表测量系统用射频前端收发组件的设计方案。详细阐述了主要功能单元电路和重要技术指标的设计考虑。该射频前端达到的指标为:输出发射功率大于16 W,输出功率全温稳定性小于0.1 d B/10℃,收发隔离大于112 d Bc,端口泄漏小于34 d BμV等。展开更多
基金supported by the National Natural Science Foundation of China (Grant No.60372055)the Hi-Tech Research and Development Program of China (No.2003AA123320 and 20030698027).
文摘A new auto-reference(AR)transmit-receive scheme and a corresponding group decision algorithm on the generalized likelihood ratio testing(GLRT)principle is proposed in this paper to overcome the drawbacks of the power inefficiency and the high noise vulnerability in transmitted-reference(TR)ultra-wideband(UWB)systems.A partly overlapped detection window structure is introduced in which the decided data frames are regarded as the reference signal so that energy and time resources in the reference frame are saved and full-rate data transmission is achieved.Differential coding was utilized to solve the error propagation problem introduced by the overlapped detection windows.The group decision algorithm on the GLRT principle was utilized to estimate the correlation template through all data frames in detection windows and could offer better noise suppression.Simulation results reveal that the AR scheme with its decision algorithm outperforms the conventional and other modified TR schemes in generalized signal-to-noise ratio(SNR).
文摘针对时间反演(time reversal,TR)技术无法较好地解决聚焦区内非法用户窃听的问题,提出了一种TR技术联合接收端人工噪声的物理层安全传输方案。首先,利用时间反演技术的空时聚焦性提高合法用户接收端的信噪比(signal to noise ratio,SNR)。其次,通过在接收端加入人工噪声来干扰非法用户对合法用户保密信息的窃听,以聚焦区内外系统安全性能为基础,推导出保密信干噪比(signal to interference plus noise ratio,SINR)、可达保密速率和误码率(bit error rate,BER)的解析表达式。最后,通过仿真分析证明了所提方案能提高系统的SINR和可达保密速率,同时还能降低合法用户的BER,使系统拥有更好的安全性能。
