This disclosure provides a method for determining channel
delay, a
delay calibration
system, and a testing device. The method includes: in response to the transmission of a measurement
signal, starting to time the
transmission delay of a
transmission channel using a first timing
granularity; determining a first timing result based on the first timing
granularity upon receiving a measurement feedback
signal through the
transmission channel; determining a second timing result based on a
delay of a second timing
granularity within the timing period of the first timing granularity at which the measurement feedback
signal is received, based on the difference between the measurement feedback signal and the expected feedback signal; increasing the
transmission delay of the transmission signal using a third timing granularity until the received measurement feedback signal meets a preset condition, and determining a third timing result based on the third timing granularity; wherein the third timing granularity is smaller than the second timing granularity and smaller than the first timing granularity; and determining the
transmission channel delay based on the first timing result, the second timing result, and the third timing result. This method for determining channel delay is simple in design and cost-effective.