The in-phase and quadrature-phase imbalance (IQI) is one of the major radio frequency impairments existing in orthogonal frequency division multiplexing (OFDM) systems with direct-conversion transceivers. During the t...The in-phase and quadrature-phase imbalance (IQI) is one of the major radio frequency impairments existing in orthogonal frequency division multiplexing (OFDM) systems with direct-conversion transceivers. During the transmission of the communication signal, the impact of IQI is coupled with channel impulse responses (CIR), which makes the traditional channel estimation schemes ineffective. A decoupled estimation scheme is proposed to separately estimate the frequency-dependent IQI and wireless channel. Firstly, the generalized channel model is built to separate the parameters of IQI and wireless channel. Then an iterative estimation scheme of frequency-dependent IQI is designed at the initial stage of communication. Finally, based on the estimation result of IQI, the least square algorithm is utilized to estimate the channel-related parameters at each time of channel variation. Compared with the joint estimation schemes of IQI and channel, the proposed decoupled estimation scheme requires much lower training overhead at each time of channel variation. Simulation results demonstrate the good estimation performance of the proposed scheme.展开更多
系统级电路辐照效应的复杂性对建模方法提出了高精度与高速度的双重要求。CMOS(互补金属氧化物半导体)工艺收发器作为系统级电路的核心常用器件,其总剂量效应的精准建模仿真至关重要。为此,本文提出一种适用于CMOS收发器的总剂量效应行...系统级电路辐照效应的复杂性对建模方法提出了高精度与高速度的双重要求。CMOS(互补金属氧化物半导体)工艺收发器作为系统级电路的核心常用器件,其总剂量效应的精准建模仿真至关重要。为此,本文提出一种适用于CMOS收发器的总剂量效应行为级仿真方法:采用输入输出缓冲区信息规范(input/output buffer information specification,IBIS)模型表征Hi-1573器件的缓冲区特性,通过VHDL-AMS语言完成器件功能区的精细化建模。为验证方法有效性,开展了^(60)Co伽马射线辐照实验,基于实验数据优化总剂量效应模块参数,将其与IBIS总剂量效应模型融合进行仿真。结果显示,仿真结果与实验数据的性能退化趋势高度吻合,充分证明了该行为级仿真方法在CMOS收发器总剂量效应建模中的可行性与可靠性。展开更多
Radio frequency identification(RFID) is a ubiquitous identification technology nowadays. An on-chip high-performance transmit/receive(T/R) switch is designed and simulated in 0.13-μm CMOS technology for reader-less R...Radio frequency identification(RFID) is a ubiquitous identification technology nowadays. An on-chip high-performance transmit/receive(T/R) switch is designed and simulated in 0.13-μm CMOS technology for reader-less RFID tag. The switch utilizes only the transistor width and length(W/L) optimization, proper gate bias resistor and resistive body floating technique and therefore,exhibits 1 d B insertion loss, 31.5 d B isolation and 29.2 d Bm 1-d B compression point(P1d B). Moreover, the switch dissipates only786.7 n W power for 1.8/0 V control voltages and is capable of switching in 794 fs. Above all, as there is no inductor or capacitor used in the circuit, the size of the switch is 0.00208 mm2 only. This switch will be appropriate for reader-less RFID tag transceiver front-end as well as other wireless transceivers operated at 2.4 GHz band.展开更多
针对通信系统国产化的需求,采用国产射频收发芯片,从硬件与软件两个方面开发,设计了一套完整的软件无线电(Software Defined Radio,SDR)系统。以Zynq-7000芯片作为数字基带验证平台,利用Verilog和C语言进行开发,通过自主设计调制解调IP...针对通信系统国产化的需求,采用国产射频收发芯片,从硬件与软件两个方面开发,设计了一套完整的软件无线电(Software Defined Radio,SDR)系统。以Zynq-7000芯片作为数字基带验证平台,利用Verilog和C语言进行开发,通过自主设计调制解调IP核,实现了全双工模式下无线数据收发功能。依据国产射频收发芯片系统架构,提出了一种改进型正交相移键控(Quadrature Phase Shift Keying,QPSK)结构,并通过自定义通信协议成功实现数据收发。该系统性能稳定可靠,能够在户外500 m以上的范围内有效通信,未出现误码,且功耗低于7.5 W。展开更多
基金supported by the National Natural Science Foundation of China(6140123261471200+4 种基金6150124861501254)the China Postdoctoral Science Foundation(2014M561692)the Jiangsu Province Postdoctoral Science Foundation(1402087C)the NUPTSF(NY213063)
文摘The in-phase and quadrature-phase imbalance (IQI) is one of the major radio frequency impairments existing in orthogonal frequency division multiplexing (OFDM) systems with direct-conversion transceivers. During the transmission of the communication signal, the impact of IQI is coupled with channel impulse responses (CIR), which makes the traditional channel estimation schemes ineffective. A decoupled estimation scheme is proposed to separately estimate the frequency-dependent IQI and wireless channel. Firstly, the generalized channel model is built to separate the parameters of IQI and wireless channel. Then an iterative estimation scheme of frequency-dependent IQI is designed at the initial stage of communication. Finally, based on the estimation result of IQI, the least square algorithm is utilized to estimate the channel-related parameters at each time of channel variation. Compared with the joint estimation schemes of IQI and channel, the proposed decoupled estimation scheme requires much lower training overhead at each time of channel variation. Simulation results demonstrate the good estimation performance of the proposed scheme.
文摘系统级电路辐照效应的复杂性对建模方法提出了高精度与高速度的双重要求。CMOS(互补金属氧化物半导体)工艺收发器作为系统级电路的核心常用器件,其总剂量效应的精准建模仿真至关重要。为此,本文提出一种适用于CMOS收发器的总剂量效应行为级仿真方法:采用输入输出缓冲区信息规范(input/output buffer information specification,IBIS)模型表征Hi-1573器件的缓冲区特性,通过VHDL-AMS语言完成器件功能区的精细化建模。为验证方法有效性,开展了^(60)Co伽马射线辐照实验,基于实验数据优化总剂量效应模块参数,将其与IBIS总剂量效应模型融合进行仿真。结果显示,仿真结果与实验数据的性能退化趋势高度吻合,充分证明了该行为级仿真方法在CMOS收发器总剂量效应建模中的可行性与可靠性。
基金supported by the research grant Economic Transformation Programme (ETP-2013-037) from Universiti Kebangsaan Malaysia and the Ministry of Science, Technology and Innovation (MOSTI) respectively
文摘Radio frequency identification(RFID) is a ubiquitous identification technology nowadays. An on-chip high-performance transmit/receive(T/R) switch is designed and simulated in 0.13-μm CMOS technology for reader-less RFID tag. The switch utilizes only the transistor width and length(W/L) optimization, proper gate bias resistor and resistive body floating technique and therefore,exhibits 1 d B insertion loss, 31.5 d B isolation and 29.2 d Bm 1-d B compression point(P1d B). Moreover, the switch dissipates only786.7 n W power for 1.8/0 V control voltages and is capable of switching in 794 fs. Above all, as there is no inductor or capacitor used in the circuit, the size of the switch is 0.00208 mm2 only. This switch will be appropriate for reader-less RFID tag transceiver front-end as well as other wireless transceivers operated at 2.4 GHz band.
