Method of chip interleaving in direct sequence spread spectrum communications

• US 6,061,386 A
• Filed: 03/19/1997
• Issued: 05/09/2000
• Est. Priority Date: 03/19/1997
• Status: Expired due to Fees

• Current Assignee: IC Com Limited
• Original Assignee: IC Com Limited
• Inventors: Molev-Shteiman, Arkady
• Primary Examiner(s): Chin, Stephen
• Assistant Examiner(s): Fan, Chieh M.
• Application Number:
  US08/820,786
• Time in Patent Office: 1,147 Days
• Field of Search: 370/470, 370/476, 370/515, 375/200, 375/206, 375/208, 375/209, 375/130, 375/140, 375/142, 375/145, 375/146, 375/150, 375/354, 375/367, 455/63, 455/138
• US Class Current: 375/140
• CPC Class Codes: H04B 1/707 using direct sequence modulation
• CPC Class Codes: H04J 13/102 Combining codes
• CPC Class Codes: H04J 3/0602 Systems characterised by the synchronising information used
• CPC Class Codes: H04L 1/0071 Use of interleaving interleaving per se H03M13/27
• CPC Class Codes: H04L 7/10 Arrangements for initial synchronisation

Abstract

A method of chip interleaving in direct sequence spread spectrum communications. A binary code sequence is chosen to have a length N=2^k -1 and to be self-orthogonal. A data string of M=QN±1 bits, where Q is a positive integer, is multiplied sequentially with the binary code sequence until N chip frames of M chips each are produced. These chip frames are transmitted to a receiver, and recovered in an equally straightforward manner. The integers Q and N are chosen according to transmission conditions.

Claims

1. An improved method for transmitting a number M of data bits from a transmitter to a receiver, the method being of the type in which a plurality of chip frames are formed by multiplying each of the data bits by N of the chips of a pseudorandom binary interleaving code sequence, thereby producing a set of N product chips corresponding to each bit, and interleaving the product chips so that each chip frame includes a unique one of the product chips from each bit, the improvement comprising the steps of:

(a) selecting an integer Q;

(b) selecting N to be one less than a power of two;

(c) selecting M to be equal to an integer selected from the group of integers consisting of QN+1 and QN-1;

(d) providing, at the transmitter and at the receiver, a pseudorandom binary interleaving code sequence, of N chips, selected from the group of sequences consisting of self-orthogonal sequences and approximately self-orthogonal sequences; and

(e) multiplying, at the transmitter, each of the M data bits by each of said N chips of said pseudorandom binary interleaving code sequence, thereby producing a packet of N chip frames, said packet including NM product chips.

2. The method of claim 1, wherein said Q is selected equal to one.

3. The method of claim 1, wherein said pseudorandom binary interleaving code sequence is a gold code sequence.

4. The method of claim 1, further comprising the step of:

(f) multiplying, at the receiver, product integers corresponding to said product chips of said packet by each of N code integers corresponding to said N chips of said pseudorandom binary interleaving code sequence, thereby producing N sequences of received integers, each of said N sequences of received integers including M received integers.

5. The method of claim 4, further comprising the step of:

(g) accumulating, at the receiver, said N sequences of received integers, thereby producing a sequence of M accumulated integers.

6. The method of claim 1, further comprising the step of:

(f) transmitting at least one pseudorandom binary acquisition code sequence from the transmitter to the receiver.

7. The method of claim 6, wherein said at least one pseudorandom binary acquisition code sequence is selected from the group of sequences consisting of self-orthogonal sequences and approximately self-orthogonal sequences.

8. The method of claim 7, wherein said at least one pseudorandom binary acquisition code sequence is a gold code sequence.

9. The method of claim 6, further comprising the step of:

(g) transmitting an acknowledgment from the receiver to the transmitter.

10. The method of claim 1, further comprising the step of:

(f) including a synchronization frame in each of a plurality of said chip frames.

11. The method of claim 10, wherein said synchronization frames are identical.

12. The method of claim 10, wherein each of said synchronization frames is selected from the group of sequences consisting of self-orthogonal sequences and approximately self-orthogonal sequences.

13. The method of claim 12, wherein each of said synchronization frames is a gold code sequence.

14. The method of claim 10, wherein at least one of said synchronization frames is identical to the pseudorandom binary interleaving code sequence.

15. The method of claim 1, wherein said multiplying of each of the M data bits, by each of said N chips of said pseudorandom binary interleaving code sequence, is effected sequentially.

16. The method of claim 15, further comprising the step of:

(f) sequentially multiplying, at the receiver, product integers corresponding to said product chips of said packet by each of N code integers corresponding to said N chips of said pseudorandom binary interleaving code sequence, thereby producing N sequences of received integers, each of said N sequences of received integers including M received integers.

17. An improved method for transmitting a number M of data bits from a transmitter to a receiver, the method being of the type in which a plurality of chip frames are formed by multiplying each of the data bits by N of the chips of a pseudorandom binary interleaving code sequence, thereby producing a set of N product chips corresponding to each bit, and interleaving the product chips so that each chip frame includes a unique one of the product chips from each bit, the improvement comprising the steps of:

(a) including a synchronization frame in each of a plurality of said chip frames, at least one of said synchronization frames being identical to the pseudorandom binary interleaving code sequence.

18. The method of claim 17 wherein said synchronization frames are identical.

19. The method of claim 17 wherein said synchronization frames are selected from the group of sequences consisting of self-orthogonal sequences and approximately self-orthogonal sequences.

20. The method of claim 19, wherein said synchronization frames are gold code sequences.

21. The method of claim 17 further comprising the step of:

(b) transmitting at least one pseudorandom binary acquisition code sequence from the transmitter to the receiver.

22. The method of claim 21, wherein said at least one pseudorandom binary acquisition code sequence is selected from the group of sequences consisting of self-orthogonal sequences and approximately self-orthogonal sequences.

23. The method of claim 22, wherein said at least one pseudorandom binary acquisition code sequence is a gold code sequence.

24. The method of claim 20, further comprising the step of:

(c) transmitting an acknowledgment from the receiver to the transmitter.

25. The method of claim 17, wherein successive said synchronization frames are differently shifted versions of the pseudorandom binary interleaving code sequence.