This paper presents an innovative switched-mode auto gain control （AGC） circuit with internally created reset module for DC-10Mb/s burst-mode unbalanced （BMU） optical data transmission. Conventional AGC circuit is...This paper presents an innovative switched-mode auto gain control （AGC） circuit with internally created reset module for DC-10Mb/s burst-mode unbalanced （BMU） optical data transmission. Conventional AGC circuit is inappropriate for BMU data transmission because it is based on average level detection and requires considerable time to settle on a predefined gain. Therefore, we adopt a fast switched-mode AGC based on peak level detection. After the gain is adjusted, the peak level detectors need to re-detect the peak level of the input signal. Thus, we develop an internally created reset module. This AGC with reset module exhibits a fast operation and achieves an adjusted stable gain within one-bit, avoiding any bit loss up to 10Mb/s data rate. During power-up, the peak level detectors possibly hold an uncertain level resulting in the bit-errors. We propose a power-up reset circuit to solve this problem. Designed in a 0.5μm CMOS technology, the circuit achieves an optical sensitivity of better than -30dBm and a wide dynamic range of over 30dB with a power dissipation of only 30 mW from a 5V supply.展开更多
自动增益控制(Automatic Gain Control,AGC)电路是接收机的重要组成部分,其作用是改善接收机的动态范围。采用反馈型自动增益控制结构,通过控制可变增益放大器AD603和电子开关,设计一个大动态范围快速闭环的AGC电路。实测结果表明,其动...自动增益控制(Automatic Gain Control,AGC)电路是接收机的重要组成部分,其作用是改善接收机的动态范围。采用反馈型自动增益控制结构,通过控制可变增益放大器AD603和电子开关,设计一个大动态范围快速闭环的AGC电路。实测结果表明,其动态增益控制范围为-10~+70 dB,闭环时间为30μs,能够广泛应用于各种定频、跳频通信,保证接收机正常工作。展开更多
针对3G终端通话时语音不够平滑圆润的问题,提出在3G上行和下行语音链路中增加自动增益控制(automatic gain control,AGC)模块。AGC模块通过自适应更新增益值算法能够防止通话过程中的语音幅度过大,从而避免语音数据经过数字增益后发生溢...针对3G终端通话时语音不够平滑圆润的问题,提出在3G上行和下行语音链路中增加自动增益控制(automatic gain control,AGC)模块。AGC模块通过自适应更新增益值算法能够防止通话过程中的语音幅度过大,从而避免语音数据经过数字增益后发生溢出,同时能对小信号进行有效地放大,对时域语音质量进行均衡,使通话双方感到语音质量自然流畅。但是如果不对现有AGC算法进行改进,处理后的语音中会产生非线性失真。改进后的AGC不仅可以使输出语音的幅值在一个预先规定的范围内,根据预先设定的门限值,放大小信号,限制强信号,防止通话过程中的语音信号过载,同时能避免非线性失真。经过理论评估和实际验证,该模块能够有效地放大小信号,限制强信号,从而增强移动终端通话质量。展开更多
基金Supported by the Natural Science Foundation of Jiangsu Province （ BK2010411 ） and the National International Cooperation Project of China-Korea （2011DFA11310）.
文摘This paper presents an innovative switched-mode auto gain control （AGC） circuit with internally created reset module for DC-10Mb/s burst-mode unbalanced （BMU） optical data transmission. Conventional AGC circuit is inappropriate for BMU data transmission because it is based on average level detection and requires considerable time to settle on a predefined gain. Therefore, we adopt a fast switched-mode AGC based on peak level detection. After the gain is adjusted, the peak level detectors need to re-detect the peak level of the input signal. Thus, we develop an internally created reset module. This AGC with reset module exhibits a fast operation and achieves an adjusted stable gain within one-bit, avoiding any bit loss up to 10Mb/s data rate. During power-up, the peak level detectors possibly hold an uncertain level resulting in the bit-errors. We propose a power-up reset circuit to solve this problem. Designed in a 0.5μm CMOS technology, the circuit achieves an optical sensitivity of better than -30dBm and a wide dynamic range of over 30dB with a power dissipation of only 30 mW from a 5V supply.
文摘自动增益控制(Automatic Gain Control,AGC)电路是接收机的重要组成部分,其作用是改善接收机的动态范围。采用反馈型自动增益控制结构,通过控制可变增益放大器AD603和电子开关,设计一个大动态范围快速闭环的AGC电路。实测结果表明,其动态增益控制范围为-10~+70 dB,闭环时间为30μs,能够广泛应用于各种定频、跳频通信,保证接收机正常工作。
文摘针对3G终端通话时语音不够平滑圆润的问题,提出在3G上行和下行语音链路中增加自动增益控制(automatic gain control,AGC)模块。AGC模块通过自适应更新增益值算法能够防止通话过程中的语音幅度过大,从而避免语音数据经过数字增益后发生溢出,同时能对小信号进行有效地放大,对时域语音质量进行均衡,使通话双方感到语音质量自然流畅。但是如果不对现有AGC算法进行改进,处理后的语音中会产生非线性失真。改进后的AGC不仅可以使输出语音的幅值在一个预先规定的范围内,根据预先设定的门限值,放大小信号,限制强信号,防止通话过程中的语音信号过载,同时能避免非线性失真。经过理论评估和实际验证,该模块能够有效地放大小信号,限制强信号,从而增强移动终端通话质量。
