1. A method for increasing acquisition efficiency in a code division multiple access (CDMA) communication system, the method comprising the following steps: receiving a first signal; generating a second signal by executing a Fourier transform operation on the first signal; determining a plurality of shift signals generated each time the second signal being shifted by a frequency; selecting a pseudo-random code from a plurality of pseudo-random codes, and obtaining a Fourier transform result of the pseudo-random code; multiplying the Fourier transform result of the pseudo-random code with the plurality of shift signals, and executing an inverse Fourier transform operation on the multiplication result to generate an inverse Fourier transform result; determining an acquisition status according to the inverse Fourier transform result; selecting another pseudo-random code from a the plurality of pseudo-random codes and obtaining a an other Fourier transform result of the an other pseudo-random code when the Fourier transform result displays an acquisition failure; multiplying the other Fourier transform result of the other pseudo-random code with the plurality of shift signals, and executing an other inverse Fourier transform operation on the an other multiplication result to generate an the other inverse Fourier transform result; and determining an the acquisition status according to the other inverse Fourier transform result.