Method and apparatus for generating pseudo random sequence in broadband wireless communication system

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;

generating a second output sequence by inputting one of m-bit initial values different from the fixed initial value to a second LFSR having m blocks;

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 non-zero delay value N; 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.

2. The method of claim 1 , further comprising constructing the first LFSR, the second LFSR, and the third LFSR, each of which has m blocks, by three different polynomials of degree m; and

wherein the constructing of the first LFSR, the second LFSR, and the third LFSR comprises:

selecting a first polynomial of degree m, and constructing the first LFSR by the first polynomial;

determining a second polynomial of degree m by sampling a binary sequence generated by the first polynomial with a sampler ƒ=1+2 └(m+2)/2┘ , and constructing the second LFSR by the second polynomial; and

determining a third polynomial of degree m by sampling a binary sequence generated by the first polynomial with a sampler ƒ=1+2 m/2 , and constructing the third LFSR by the third polynomial.

3. The method of claim 2 , wherein Large sets of Kasami sequence of degree m are generated based on the three different polynomials of degree m.

4. The method of claim 2 , wherein the first polynomial of degree m is one having the smallest number of terms among plural primitive polynomials of degree m over Galois Field of two (GF(2)), and the binary sequence generated by the first polynomial is an m-sequence.

5. The method of claim 1 , wherein the m-bit initial values input to the second LFSR are distributed on the basis of some information of which the sum of total information bits is between 1 and m bits among specific system information, and

the delay values given for the sequence output from the third LFSR are distributed on the basis of remaining information of which the sum of total information bits is between 0 and m/2 bits among the specific system information.

6. The method of claim 5 , wherein the specific system information comprises information on any one of a user equipment identification (UE ID), a cell ID, a cell group ID, a component carrier (CC) ID, a component carrier (CC) offset, a relay node ID, a Home node B (HeNB) ID, a system frame number, a subframe number, a slot number, an Orthogonal Frequency Division Multiplexing (OFDM) symbol number, a stream ID, and a Multimedia Broadcast and Multicast Service (MBMS) over Single-Frequency Network (MBSFN) area ID, per each physical channel or each physical signal of an uplink or a downlink.

7. The method of claim 1 , wherein the fixed initial value input to the first LFSR is <0,0,0,...,0,0,1> or <1,0,0,...,0,0,0> having a length of m.

8. The method of claim 1 , wherein the one of m-bit initial values input to the second LFSR is one of elements of subset of the set A, which have M elements, and

wherein the set A has total 2 m different m-bit initial values, and M (0<M≦2 m ) is determined on the basis of the number of cases of specific system information distributed to the second LFSR.

9. The method of claim 1 , wherein the predetermined initial value input to the third LFSR is constructed with first m bits of a sequence obtained by sampling a binary sequence output from the first LFSR with a sampler ƒ=1+2 m/2 .

10. The method of claim 1 , wherein the delay value N is one of total M′ different delay values from 0 to M′−1, and

wherein M′ (0≦M′≦2 m/2 ) is determined on the basis of the number of cases of the specific system information distributed to the third LFSR.

11. The method of claim 1 , wherein the fixed initial value, the one of m-bit initial values, and the predetermined initial value are input at every initialization period, and the every initialization period comprises one of a subframe period, a radio frame period, an Orthogonal Frequency Division Multiplexing (OFDM) symbol period, a slot period, and a code block period, per each physical channel or each physical signal of an uplink or a downlink.

12. 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;

generating a second output sequence by inputting one of m-bit initial values different from the fixed initial value to a second LFSR having m blocks;

generating a third output sequence by inputting one of m-bit initial values different from the fixed initial value to a third LFSR having m blocks; 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.

13. The method of claim 12 , further comprising constructing the first LSFR, the second LSFR, and the third LFSR, each of which has m blocks, by three different polynomials of degree m, and

wherein one of 3-error-correcting BCH code, Modified or Extended Gold sequence, or Modified or Extended Kasami sequence is generated based on the three different polynomials of degree m.

14. The method of claim 12 , wherein the m-bit initial values input to the second LFSR are distributed on the basis of some information of which the sum of total information bits is between 1 and m bits among specific system information, and

the m-bit initial values input to the third LFSR are distributed on the basis of remaining information of which the sum of total information bits is between 0 and m bits among the specific system information.

15. The method of claim 12 , wherein the one of m-bit initial values input to the second LFSR is one of elements of subset of set A, which have M elements, wherein the set A having total 2m different m-bit initial values, and M (0<M≦2 m ) is determined on the basis of the number of cases of specific system information distributed to the second LFSR, and

the one of m-bit initial values input to the third LFSR is one of elements of subset of set B, which have M′ elements, wherein the set B having total 2 m different m-bit initial values, and M′ (0≦M′≦2 m ) is determined on the basis of the number of cases of specific system information distributed to the third LFSR.

16. An apparatus for generating pseudo random sequence in a wireless communication system, comprising:

a first linear feedback shift register (LFSR), a second LSFR, and a third LFSR, each of which has m blocks;

a first initial value mapper to input a fixed initial value to the first LFSR;

a second initial value mapper to input one of m-bit initial values different from the fixed initial value to the second LFSR;

a third initial value mapper to input a predetermined initial value to the third LFSR;

an N delay operator to delay a sequence output from the third LFSR receiving the initial value from the third initial value mapper by N clocks for a non-zero delay value N; and

a modulo 2 operator to sum the first output sequence, the second output sequence, and the third output sequence bit by bit through a modulo 2 operation.

17. The apparatus of claim 16 , wherein the first LFSR is constructed from a first polynomial of degree m selected from plural primitive polynomials of degree m over Galois Field of two (GF(2));

the second LFSR is constructed from a second polynomial determined by sampling a binary sequence generated by the first polynomial with a sampler ƒ=1+2 └(m+2)/2┘ ; and

the third LFSR is constructed from a third polynomial determined by sampling a binary sequence generated by the first polynomial with a sampler ƒ=1+2 m/2 .

18. The apparatus of claim 16 , wherein the first LFSR, the second LFSR, and the third LFSR are constructed from three different polynomials of degree m, and Large sets of Kasami sequence of degree m are generated based on the three different polynomials of degree m.

19. An apparatus for generating pseudo random sequence in a wireless communication system, comprising:

a first linear feedback shift register (LFSR), a second LFSR, and a third LFSR, each of which has m blocks;

a first initial value mapper to input a fixed initial value to the first LFSR;

a second initial value mapper to input one of m-bit initial values different from the fixed initial value to the second LFSR;

a third initial value mapper to input one of m-bit initial values different from the fixed initial value to the third LFSR; and

a modulo 2 operator to sum the first output sequence, the second output sequence, and the third output sequence bit by bit through a modulo 2 operation.

20. The apparatus of claim 19 , wherein the first LFSR, the second LFSR, and the third LFSR are constructed from three different polynomials of degree m, and a binary sequence comprising any one of 3-error-correcting BCH code, Modified or Extended Gold sequence, or Modified or Extended Kasami sequence is generated based on the three different polynomials of degree m.

21. The method of claim 1 , wherein the one of m-bit initial values and the given delay value N are determined based on specific system information.

22. The method of claim 12 , wherein the one of m-bit initial values to the second LFSR and the one of m-bit initial values to the third LFSR are determined based on specific system information.