一种伪随机控制的2ASK调制解调电路实现

Realization of 2ASK Modulation and Demodulation Circuit with Pseudo-noise Sequence

设计一种以现场可编程门阵列(FPGA)作为伪随机序列信号发生器,通过级联方式实现幅度键控(ASK)数字调制的电路实现方法。首先通过FPGA程序控制产生"0"、"1"等概的周期长度为15的伪随机基带序列,直接数字式频率合成器(DDS)电路生成模拟载波信号,输入序列与载波信号进行ASK调制,再将ASK已调信号进行包络检波,还原出数字序列。电路测试表明,利用FPGA可以产生正确伪随机序列,ASK调制解调波形与理论分析一致,具有良好的应用价值。

An Amplitude Shift Keying（ASK） modulation circuit is implemented by means of cascade Field - programmable Gate Array （FPGA）as a pseudorandom sequence generator. First FPGA produces period length of fifteen “0”,“ 1” pseudo - random sequence, and DDS circuit generates analog carrier signal. Second, ASK modulation is finished with the input PN sequences and carrier signals. Third, the ASK modulated signal is de- modulated by envelope detection. Circuit testing shows that the expected pseudo random sequence can be pro- duced by FPGA correctly, and ASK modulation waveforms are consistent with theoretical analysis, with a good value.