1. A method for generating pseudo random sequence in a wireless communication system, comprising: generating a first output sequence by inputting a fixed initial value to a first linear feedback shift register (LFSR) having m blocks at every initialization period; generating a second output sequence by inputting one of m-bit initial values to a second LFSR having m blocks at every initialization period; after inputting a predetermined initial value to a third LFSR having m blocks, generating a third output sequence by delaying a sequence output from the third LFSR by a given delay value N, at every initialization period; and generating the pseudo random sequence by summing the first output sequence, the second output sequence and the third output sequence bit by bit through a modulo 2 operation.