InterRange Instrumentation Group（IRIG-B（AC））code is usually used in the shooting range test for time information transmission and systems time synchronization.According to IRIG-B（AC）code format and modulation pr...InterRange Instrumentation Group（IRIG-B（AC））code is usually used in the shooting range test for time information transmission and systems time synchronization.According to IRIG-B（AC）code format and modulation principle,this paper presents IRIG-B（AC）coding circuit design scheme based on field programmable gate array（FPGA）.The B（AC）code signal is generated by AD7245,a digital-to-analog（D/A）converter.After amplified,the signal can be used directly for system time synchronization,and the amplitude of the signal can be adjusted according to different requirements.The IRIG-B（AC）encoder designed has been verified by test.The test results show that it can output accurate time information and has higher practicality.展开更多
A passive optical network （PON） scheme based on optical code division multiplexing （OCDM） for the downstream traffics is proposed and analyzed in detail. In the PON, the downstream traffics are broadcasted by OCDM...A passive optical network （PON） scheme based on optical code division multiplexing （OCDM） for the downstream traffics is proposed and analyzed in detail. In the PON, the downstream traffics are broadcasted by OCDM technology to guarantee the security, while the upstream traffics pass through the same optical fiber by the common time division multiple access （TDMA） technology to decrease the cost. This schemes are denoted as OCDM/TDMA-PON, which can be applied to an optical access network （OAN） with full services on demand, such as Internet protocol, video on demand, tele-presence and high quality audio. The proposed OCDM/TDMA-PON scheme combines advantages of PON, TDMA, and OCDM technology. Simulation results indicate that the designed scheme improves the OAN performance, and enhances flexibility and scalability of the system.展开更多
基金The 10th Postgraduate Science and Technology Fund of North University of China(No.20131020)
文摘InterRange Instrumentation Group（IRIG-B（AC））code is usually used in the shooting range test for time information transmission and systems time synchronization.According to IRIG-B（AC）code format and modulation principle,this paper presents IRIG-B（AC）coding circuit design scheme based on field programmable gate array（FPGA）.The B（AC）code signal is generated by AD7245,a digital-to-analog（D/A）converter.After amplified,the signal can be used directly for system time synchronization,and the amplitude of the signal can be adjusted according to different requirements.The IRIG-B（AC）encoder designed has been verified by test.The test results show that it can output accurate time information and has higher practicality.
文摘A passive optical network （PON） scheme based on optical code division multiplexing （OCDM） for the downstream traffics is proposed and analyzed in detail. In the PON, the downstream traffics are broadcasted by OCDM technology to guarantee the security, while the upstream traffics pass through the same optical fiber by the common time division multiple access （TDMA） technology to decrease the cost. This schemes are denoted as OCDM/TDMA-PON, which can be applied to an optical access network （OAN） with full services on demand, such as Internet protocol, video on demand, tele-presence and high quality audio. The proposed OCDM/TDMA-PON scheme combines advantages of PON, TDMA, and OCDM technology. Simulation results indicate that the designed scheme improves the OAN performance, and enhances flexibility and scalability of the system.
