be valid in this case the sf value length cannot be exactly distinguished that is according to an estimation method of the related art it cannot be determined whether a used ovsf code is c ch 8 0 1 1 1 1 1 1 1 1 c ch 4 0 1 1 1 1 or c ch 2 0 1 1 in consideration of the above according to the present invention there is proposed a method of exactly estimating an sf value by using a zcr fig2 is a flowchart illustrating a method of blindly estimating a wcdma ovsf code for a signal analyzer according to the present invention first a signal analyzer down converts an rf signal received from a base station to obtain a base band iq signal corresponding to an amount of one frame and a d converts the base band iq signal then the signal analyzer descrambles the a d converted base band iq signal with a suitable scrambling code to obtain descrambled iq data the present invention may be performed with such descrambled iq data hereinafter the present invention will be described without distinguishing i and q from each other first in step s 10 an sf is set to have the longest length of 512 2 9 and the idex idx is set to be u2018 0 u2019 in step s 20 the power average value of a symbol obtained by despreading the descrambled data with the set ovsf code is calculated the code domain power cdp of the corresponding code may be used as the power average value of the symbol then in.