Energy detection method and an energy detection circuit using the same

An energy detection circuit used in a receiver for obtaining a signal initial time point corresponding to the input signal with reference to a signal corresponding to an input signal, wherein the energy detection circuit comprises:

• a value obtaining switch turned on in response to a control signal to provide an ith sample value of the signal at a first sampling time point, wherein is a natural number greater than 1;
• a shift register used for buffering an (i−M−N+1)th to the ith sample values, wherein M and N both are natural numbers greater than 1, and the shift register comprises:
• a first sliding window value obtainer used for buffering the (i−M−N+1)th to an (i−N)th sample values;
• a second sliding window value obtainer used for buffering an (i−N+1)th to the ith sample value;
• a first arithmetic unit used for obtaining a first parameter according to a weighting coefficient K and the (i−M−N+1)th to the (i−N)th sample values;
• a second arithmetic unit used for obtaining a second parameter according to the (i−N+1)th to the ith sample values;
• a comparator used for comparing the first parameter to the second parameter, and providing an energy detection signal when the second parameter is greater than the first parameter;
• and
• a processor used for setting the weighting coefficient K with an initial value, wherein the processor further determines whether the energy detection signal is received, and the processor determines an (i−N+1)th sampling time point of the (i−N+1)th sample value as the signal initial time point when the energy detection signal is received.