SYSTEM AND METHOD FOR INFORMATION SCRAMBLING IN A WIRELESS COMMUNICATION SYSTEM

• US 20080159537A1
• Filed: 09/30/2007
• Published: 07/03/2008
• Est. Priority Date: 01/03/2007
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Khan, Farooq, Tsai, Jiann-An
• Granted Patent: US 8,243,774 B2
• Time in Patent Office: Days
• US Class Current: 380/268
• CPC Class Codes: H04L 25/03866 using scrambling
• CPC Class Codes: H04L 27/34 Amplitude- and phase-modulated carrier systems, e.g. quadrature-amplitude modulated carrier systems
• CPC Class Codes: H04L 5/0016 Time-frequency-code

Abstract

The present disclosure relates generally to a system and method for scrambling in a wireless communication system. In one example, the method includes receiving a bit group representing at least a portion of a signal, where a total number of bits in the bit group is defined by a modulation scheme applied to the signal. A bit of the bit group is identified that indicates a sign of an imaginary part of the signal and another bit of the bit group is identified that indicates a sign of a real part of the signal. Only the two bits indicating the signs of the imaginary and real parts of the signal are scrambled using a random sequence prior to wirelessly transmitting the bit group.

Claims

1. A method comprising:

receiving a bit group representing at least a portion of a signal, wherein a total number of bits in the bit group is defined by a modulation scheme applied to the signal;

identifying a first bit of the bit group that indicates a sign of an imaginary part of the signal;

identifying a second bit of the bit group that indicates a sign of a real part of the signal; and

scrambling only the first and second bits of the bit group using a random sequence prior to wirelessly transmitting the bit group.

2. The method of claim 1 further comprising converting the bit group prior to the scrambling, wherein the converting formats the bits in the bit group in preparation for the scrambling.

3. The method of claim 2 wherein the converting changes each ‘

1’

bit of the bit group into a ‘

+1’

bit and each ‘

0’

bit of the bit group into a ‘

−

1’

bit.

4. The method of claim 1 further comprising modulating the bit group prior to the scrambling.

5. The method of claim 1 further comprising modulating the bit group after performing the scrambling.

6. The method of claim 1 further comprising using a different random sequence for each of the first and second bits.

7. The method of claim 6 further comprising:

generating a random sequence value for each bit of the bit group; and

ignoring the random sequence value for each bit of the bit group except the first and second bits.

8. The method of claim 1 wherein the total number of bits in the bit group is two.

9. A method comprising:

wirelessly receiving a bit group representing at least a portion of a signal;

identifying a first bit of the bit group that indicates a sign of an imaginary part of the signal;

identifying a second bit of the bit group that indicates a sign of a real part of the signal; and

descrambling only the first and second bits of the bit group using a random sequence that corresponds to a random sequence used to scramble only the first and second bits of the bit group prior to transmission.

10. The method of claim 9 further comprising demodulating the bit group prior to the descrambling.

11. The method of claim 9 further comprising demodulating the bit group after performing the descrambling.

12. The method of claim 9 further comprising using a different random sequence for descrambling each of the first and second bits.

13. A transmission system comprising:

a modulation block configured to modulate a signal for transmission;

a random sequence coding block coupled to the modulation block and configured to scramble only bits of the signal indicating a sign of an imaginary part and a real part of the signal without scrambling the remaining bits of the signal; and

transmission circuitry configured to transmit the modulated and scrambled signal via an antenna.

14. The transmission system of claim 13 wherein the modulation block is positioned relative to the random sequence coding block so that modulation occurs prior to scrambling.

15. The transmission system of claim 13 wherein the modulation block is positioned relative to the random sequence coding block so that modulation occurs after scrambling.

16. The transmission system of claim 13 wherein the random sequence coding block is configured to use a different random sequence for each of the first and second bits.

17. The transmission system of claim 13 further comprising an error check block configured to add error correction information to the signal prior to transmission.

18. A receiving system comprising:

receiving circuitry configured to receive a modulated and scrambled signal via an antenna;

a demodulation block configured to demodulate the signal; and

a random sequence decoding block coupled to the demodulation block and configured to descramble only bits of the signal indicating a sign of an imaginary part and a real part of the signal without descrambling the remaining bits of the signal.

19. The receiving system of claim 18 wherein the demodulation block is positioned relative to the random sequence decoding block so that demodulation occurs prior to descrambling.

20. The receiving system of claim 18 wherein the demodulation block is positioned relative to the random sequence decoding block so that demodulation occurs after descrambling.

21. The receiving system of claim 18 wherein the random sequence decoding block is configured to use a different random sequence for each of the first and second bits.