本文研究多载波正交频分复用超宽带(multiband-OFDM-ultra wideband,MB-OFDM-UWB)系统与WiMAX(world interoperability for microwave access)系统之间的共存干扰问题。使用ADS仿真平台建立仿真模型,对两个系统之间的频率干扰特性进行仿...本文研究多载波正交频分复用超宽带(multiband-OFDM-ultra wideband,MB-OFDM-UWB)系统与WiMAX(world interoperability for microwave access)系统之间的共存干扰问题。使用ADS仿真平台建立仿真模型,对两个系统之间的频率干扰特性进行仿真,同时针对UWB系统有无采用检测避让(detect and avoid,DAA)技术的情况,对各个系统的误帧率进行仿真。仿真结果表明,MB-OFDM-UWB系统与WiMAX系统间存在同频干扰,使用DAA技术可以有效地抑制或降低系统间的同频干扰影响,实现系统共存。展开更多
基于抑制MB-OFDM-UWB系统中干扰信号的目的,提出了一种抑制系统带宽内干扰信号的新算法。该算法采用两组自适应干扰对消滤波器,利用LMS方法来实现对干扰信号的抑制。通过仿真,在接收端利用频谱和星座图两种途径分析了该算法对干扰信号...基于抑制MB-OFDM-UWB系统中干扰信号的目的,提出了一种抑制系统带宽内干扰信号的新算法。该算法采用两组自适应干扰对消滤波器,利用LMS方法来实现对干扰信号的抑制。通过仿真,在接收端利用频谱和星座图两种途径分析了该算法对干扰信号的抑制效果。仿真结果表明,该算法在不损失带内有用信号电平的情况下,对干扰信号抑制达到30 d B。因此,对UWB信号带内的干扰信号起到了良好的抑制作用。展开更多
The single sideband （SSB） modulation is assessed as a means to mitigate the dispersion-induced power fading on the distribution of ortogonal frequency division multiplexing （OFDM） ultra wideband （UWB） radio sign...The single sideband （SSB） modulation is assessed as a means to mitigate the dispersion-induced power fading on the distribution of ortogonal frequency division multiplexing （OFDM） ultra wideband （UWB） radio signals along long-reach passive optical networks （LR-PONs）. Particularly, two different SSB ar- chitectures, namely, Sieben＇s architecture and four phase modulator （FPM） architecture are optimized to provide maximum sideband suppression. The minimum optical signal-to-noise ratio （OSNR） required to simultaneously distribute all the 14 OFDM-UWB sub-bands along the LR-PON distances ranging between 80 and 100 km is also evaluated through numerical simulation. FPM architecture is preferable over Sieben＇s architecture because the latter SSB architecture generates carriers-carriers beat term at the photodetector output with high power, thereby causing significant degradation in the OFDM-UWB sub-bands with lower central frequencies. The simultaneous distribution of the 14 SSB OFDM-UWB sub-bands in the LR-PON using the FPM architecture shows a minimum OSNR penalty of 3 dB compared with the centralized dis- persion compensation technique.展开更多
This paper presents a fully integrated dual-mode 6 to 9 GHz transmitter for both WiMedia and China MB-OFDM UWB applications. The proposed transmitter consists of a dual-mode I/Q LPF, an up-conversion mixer, a two-stag...This paper presents a fully integrated dual-mode 6 to 9 GHz transmitter for both WiMedia and China MB-OFDM UWB applications. The proposed transmitter consists of a dual-mode I/Q LPF, an up-conversion mixer, a two-stage power driver amplifier and a broadband high-speed frequency divider with LO buffers for I/Q LO carrier generation. The measurement results show that the gain ripple of the transmitter is within ±1.5/±2.8 dB from 6 to 8.7/9 GHz. The output IP3 is about ＋13.2 dBm, the output 1 dBCP is around ＋2.8 dBm, and the LO leakage/sideband rejection ratio is about-35/-38 dBc. The ESD protected chip is fabricated with a TSMC 0.13 μm RFCMOS process with a die size of 1.6 × 1.3 mm^2 and the core circuit consumes only 46 mA under a 1.2 V supply.展开更多
文摘本文研究多载波正交频分复用超宽带(multiband-OFDM-ultra wideband,MB-OFDM-UWB)系统与WiMAX(world interoperability for microwave access)系统之间的共存干扰问题。使用ADS仿真平台建立仿真模型,对两个系统之间的频率干扰特性进行仿真,同时针对UWB系统有无采用检测避让(detect and avoid,DAA)技术的情况,对各个系统的误帧率进行仿真。仿真结果表明,MB-OFDM-UWB系统与WiMAX系统间存在同频干扰,使用DAA技术可以有效地抑制或降低系统间的同频干扰影响,实现系统共存。
文摘基于抑制MB-OFDM-UWB系统中干扰信号的目的,提出了一种抑制系统带宽内干扰信号的新算法。该算法采用两组自适应干扰对消滤波器,利用LMS方法来实现对干扰信号的抑制。通过仿真,在接收端利用频谱和星座图两种途径分析了该算法对干扰信号的抑制效果。仿真结果表明,该算法在不损失带内有用信号电平的情况下,对干扰信号抑制达到30 d B。因此,对UWB信号带内的干扰信号起到了良好的抑制作用。
基金supported by Fundacao para a Cienciae a Tecnologia from Portugal under contract SFRH/BD/29871/2006 the project TURBO-PTDC/EEA-TEL/104358/2008supported in part by the European FIVER-FP7-ICT-2009-4-249142 project
文摘The single sideband （SSB） modulation is assessed as a means to mitigate the dispersion-induced power fading on the distribution of ortogonal frequency division multiplexing （OFDM） ultra wideband （UWB） radio signals along long-reach passive optical networks （LR-PONs）. Particularly, two different SSB ar- chitectures, namely, Sieben＇s architecture and four phase modulator （FPM） architecture are optimized to provide maximum sideband suppression. The minimum optical signal-to-noise ratio （OSNR） required to simultaneously distribute all the 14 OFDM-UWB sub-bands along the LR-PON distances ranging between 80 and 100 km is also evaluated through numerical simulation. FPM architecture is preferable over Sieben＇s architecture because the latter SSB architecture generates carriers-carriers beat term at the photodetector output with high power, thereby causing significant degradation in the OFDM-UWB sub-bands with lower central frequencies. The simultaneous distribution of the 14 SSB OFDM-UWB sub-bands in the LR-PON using the FPM architecture shows a minimum OSNR penalty of 3 dB compared with the centralized dis- persion compensation technique.
基金Project supported by the National Science and Technology Major Projects of China(Nos.2009ZX03006-007-01,2009ZX03007-001, 2009ZX03006-009)the National High Technology R&D Program of China(No.2009AA01Z261).
文摘This paper presents a fully integrated dual-mode 6 to 9 GHz transmitter for both WiMedia and China MB-OFDM UWB applications. The proposed transmitter consists of a dual-mode I/Q LPF, an up-conversion mixer, a two-stage power driver amplifier and a broadband high-speed frequency divider with LO buffers for I/Q LO carrier generation. The measurement results show that the gain ripple of the transmitter is within ±1.5/±2.8 dB from 6 to 8.7/9 GHz. The output IP3 is about ＋13.2 dBm, the output 1 dBCP is around ＋2.8 dBm, and the LO leakage/sideband rejection ratio is about-35/-38 dBc. The ESD protected chip is fabricated with a TSMC 0.13 μm RFCMOS process with a die size of 1.6 × 1.3 mm^2 and the core circuit consumes only 46 mA under a 1.2 V supply.
