Rapid and accurate sign detection method based on millimeter wave radar

The invention discloses a rapid and accurate sign detection method based on a millimeter wave radar. According to the invention, the vital sign signals can be rapidly detected, the detection precision is high, and the complexity is low. The method comprises the following steps: firstly, performing frequency mixing and cross sampling on an echo signal and a transmitting signal to obtain a complex signal; secondly, selecting an optimal distance unit under the condition that a target phase signal is not damaged by adopting a variance of slow time dimension energy based on a complex signal, and ensuring that the optimal distance unit simultaneously contains human respiration and heartbeat signals; meanwhile, before heart rate estimation is carried out, higher harmonics of the respiration signals are eliminated at first, and then the final result of the heart rate is output according to the amplitude, so that the heart rate estimation has high accuracy. According to the method, the requirements for signal processi