【摘要】 针对数字锁相环中环路的锁定时间和锁定范围这一对相互制约的因素,改进了传统的Hilbert变换鉴相器,融合模糊逻辑的非线性推理和微分控制算法,优化环路滤波器参数,充分发挥微分控制的"预测"作用。仿真结果表明,在符号率100kbps,信噪比25dB的AWGN信道条件下,分别计算二、三、四阶环路滤波参数,采用本算法设计的数字锁相环,分别比传统固定带宽条件下锁定时间小8.7、9、8.3倍,锁定范围扩大5.3、5、5.9倍。使用SMIC0.18μm工艺进行综合,并且嵌入到QAM解调芯片中进行流片,测试结果表明,本芯片可清晰接收数字电视节目,锁定时间缩短6倍以上。更多还原

【Abstract】 In DPLL design,locked time and locked range is a pair of contradictory.Conventional Hilbert phrase detector was improved in this paper.To play its full role of prediction innovatively,differential control was combined with fuzzy control.Parameters of the Loop Filter were optimized by fuzzy controller.In the condition of 2nd,3rd,4th loop,symbol rate set as 100 kbps,SNR set as 25 dB and transmitted in AWGN channel,filter parameters were calculated.Compared with conventional DPLL,locked time reduced to 8.7,9,8.3 times smaller and locked range enlarged to 5.3,5,5.9 times bigger in our carried recovery DPLL.By using SMIC 0.18μm library to synthesis,this loop was embedded into the QAM demodulation chip,testing result shows it receives transport stream clearly,locked 6 times faster,performances better.更多还原