这是用线程模拟火车票的售卖代码 比较简短 原理也比较清楚 对线程的同步理解很有帮助-This is a relatively brief principle of the sale code for the thread is impersonating the train is also more clearly understand very helpful thread synchronization

用于接收机的载波同步，利用锁相环实现解调，用于相干解调-Carrier for receiver synchronization, phase-locked loop to achieve demodulation for coherent demodulation