针对5G通信无线多媒体传输时域同步—正交频分复用(TDS-OFDM)系统中的符号定时恢复处理慢、性能距离理论界较大等问题,提出了一种并行MAP定时恢复算法。它通过拉格朗日插值,能较好地提取最佳采样点幅度与极性变化信息,检测定时误差。而...针对5G通信无线多媒体传输时域同步—正交频分复用(TDS-OFDM)系统中的符号定时恢复处理慢、性能距离理论界较大等问题,提出了一种并行MAP定时恢复算法。它通过拉格朗日插值,能较好地提取最佳采样点幅度与极性变化信息,检测定时误差。而且该算法采用了高效并行的最大后验概率(MAP)准则,高速完成定时误差估计。仿真表明,与现有MM算法、Gardner算法等相比,该算法估计精度较高,结果逼近MAP定时恢复算法,差距约2 d B。展开更多
Powerline communications （PLC） have drawn great interest in recent years. However, most PLC standards such as HomePlug AV use the cyclic-prefix OFDM （CP-OFDM） technology. This paper presents a broadband PLC system...Powerline communications （PLC） have drawn great interest in recent years. However, most PLC standards such as HomePlug AV use the cyclic-prefix OFDM （CP-OFDM） technology. This paper presents a broadband PLC system using low density parity check （LDPC） coded time domain synchronous OFDM （TDS-OFDM）, whose spectrum efficiency is about 10% higher than that of CP-OFDM. With the same bandwidth and the ability to combat the time delay spread as HomePlug AV, this system can provide a maximum throughput of 199.7 Mbps physical layer data rate. Simulations over the measured practical powerline channel in Beijing, China, show that LDPC in the TDS-OFDM system dramatically improves the bit error rate performance, and verify the feasibility and performance of the TDS-OFDM technology for PLC systems.展开更多
A spectrum efficient OFDM scheme named Time Domain Synchronous-OFDM(TDS-OFDM)is introduced into coherent optical transmission system,in which the pseudo noise(PN)sequence is exploited as guard interval to realize fram...A spectrum efficient OFDM scheme named Time Domain Synchronous-OFDM(TDS-OFDM)is introduced into coherent optical transmission system,in which the pseudo noise(PN)sequence is exploited as guard interval to realize frame synchronization,compensate the carrier frequency offset(CFO),and estimate and equalize channel simultaneously.Since there is no pilot signals or training symbols in TDS-OFDM,the proposed scheme can achieve higher spectral efficiency(SE)above 10%improvement comparing with CPOFDM.The proposed method is implemented and verified in a 28GBaud QPSK OFDM system and a 28GBaud 16QAM OFDM system.It is demonstrated that the proposed scheme shows high CFO estimation accuracy and synchronous accuracy.Under CFO and linewidth of laser source set as 100MHz and 100kHz respectively,BER of QPSK OFDM system is below 3.8e-3 at the optical signal-to-noise ratio(OSNR)of 13dB,and BER of 16QAM OFDM system is below 3.8e-3 at the OSNR of 20dB.展开更多
文摘针对5G通信无线多媒体传输时域同步—正交频分复用(TDS-OFDM)系统中的符号定时恢复处理慢、性能距离理论界较大等问题,提出了一种并行MAP定时恢复算法。它通过拉格朗日插值,能较好地提取最佳采样点幅度与极性变化信息,检测定时误差。而且该算法采用了高效并行的最大后验概率(MAP)准则,高速完成定时误差估计。仿真表明,与现有MM算法、Gardner算法等相比,该算法估计精度较高,结果逼近MAP定时恢复算法,差距约2 d B。
基金Supported by the National High-Tech Research and Development (863) Program of China (No. 2007AA01Z2B6)
文摘Powerline communications （PLC） have drawn great interest in recent years. However, most PLC standards such as HomePlug AV use the cyclic-prefix OFDM （CP-OFDM） technology. This paper presents a broadband PLC system using low density parity check （LDPC） coded time domain synchronous OFDM （TDS-OFDM）, whose spectrum efficiency is about 10% higher than that of CP-OFDM. With the same bandwidth and the ability to combat the time delay spread as HomePlug AV, this system can provide a maximum throughput of 199.7 Mbps physical layer data rate. Simulations over the measured practical powerline channel in Beijing, China, show that LDPC in the TDS-OFDM system dramatically improves the bit error rate performance, and verify the feasibility and performance of the TDS-OFDM technology for PLC systems.
基金supported by the State Grid Corporation of China (No. 5101/2017-3205A)the Open Fund of the Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications (Jinan University)the National Natural Science Foundation of China (NSFC) (61571057, 61501214, 61527820, 61575082)
文摘A spectrum efficient OFDM scheme named Time Domain Synchronous-OFDM(TDS-OFDM)is introduced into coherent optical transmission system,in which the pseudo noise(PN)sequence is exploited as guard interval to realize frame synchronization,compensate the carrier frequency offset(CFO),and estimate and equalize channel simultaneously.Since there is no pilot signals or training symbols in TDS-OFDM,the proposed scheme can achieve higher spectral efficiency(SE)above 10%improvement comparing with CPOFDM.The proposed method is implemented and verified in a 28GBaud QPSK OFDM system and a 28GBaud 16QAM OFDM system.It is demonstrated that the proposed scheme shows high CFO estimation accuracy and synchronous accuracy.Under CFO and linewidth of laser source set as 100MHz and 100kHz respectively,BER of QPSK OFDM system is below 3.8e-3 at the optical signal-to-noise ratio(OSNR)of 13dB,and BER of 16QAM OFDM system is below 3.8e-3 at the OSNR of 20dB.
