Apparatus and method for distinguishing a frame on channel shared by multiple users

• US 20070183385A1
• Filed: 10/10/2003
• Published: 08/09/2007
• Est. Priority Date: 10/10/2003
• Status: Abandoned Application

• Current Assignee: Motorola Mobility, Inc. (Lenovo Group Ltd.)
• Original Assignee: Motorola Mobility, Inc. (Lenovo Group Ltd.)
• Inventors: Bi, Hao, McBeath, Sean, Reed, John
• Application Number:
  US10/683,761
• Publication Number:
  US 20070183385A1
• Time in Patent Office: Days
• US Class Current: 370/342
• CPC Class Codes: H04L 1/0041 Arrangements at the transmitter end
• CPC Class Codes: H04L 1/0045 Arrangements at the receiver end
• CPC Class Codes: H04L 1/0061 Error detection codes
• CPC Class Codes: H04W 4/06 Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services
• CPC Class Codes: H04W 52/12 Outer and inner loops

Abstract

An apparatus and method of distinguishing a frame on a channel shared by a plurality of users. A unique identifier can be obtained for each of a set of mobile communication devices. A message intended for one of the mobile communication devices can be obtained. The message can be scrambled using a long code generated using a mobile communication device specific long code mask to obtain a scrambled message. The unique identifier can be incorporated into the scrambled message for a frame intended for a selected mobile communication device. The frame can then be transmitted. A radio frequency signal can be received for the frame. Demodulation can be performed on the signal to obtain a scrambled signal. A unique identifier can be extracted from the scrambled signal. The unique identifier extracted from the scrambled signal can be examined to determine if the signal is intended for a mobile communication device.

Claims

1. A method at a communication device of distinguishing a frame on a channel shared by a plurality of users, the method comprising:

receiving a radio frequency signal for a frame;

performing demodulation on the signal to obtain a scrambled signal;

extracting a unique identifier from the scrambled signal; and

examining the unique identifier extracted from the scrambled signal to determine if the signal is intended for the communication device.

2. The method according to claim 1, wherein receiving further comprises receiving a radio frequency signal for a frame on a forward dedicated control channel.

3. The method according to claim 1, wherein the unique identifier comprises a group identifier that identifies at least one communication device for which the signal is intended.

4. The method according to claim 1, wherein the unique identifier comprises a mobile station identity that identifies a specific communication device for which the signal is intended.

5. The method according to claim 1, wherein the unique identifier is obtained from a set of segments of the scrambled signal.

6. The method according to claim 1, further comprising:

descrambling the scrambled signal using a long code mask to obtain a channel encoded signal;

channel decoding the channel encoded signal to obtain a cyclic redundancy coded signal;

cyclic redundancy code checking the cyclic redundancy coded signal;

determining the cyclic redundancy coded signal fails the cyclic redundancy code check;

increasing a received signal quality set point if in the examining step it is determined that the signal is intended for the communication device but the cyclic redundancy coded signal fails the cyclic redundancy code check; and

decreasing the received signal quality set point if in the examining step it is determined that the signal is intended for the communication device but the cyclic redundancy coded signal passes the cyclic redundancy code check.

7. The method according to claim 1, further comprising, after extracting the unique identifier,

descrambling the scrambled signal to obtain a channel encoded signal:

and

channel decoding the channel encoded signal to obtain a cyclic redundancy coded signal.

8. A method at a mobile communication device of distinguishing a frame on a channel shared by a plurality of users, the method comprising:

receiving a radio frequency signal for a frame;

performing demodulation on the signal to obtain a scrambled signal;

descrambling the scrambled signal to obtain a channel encoded signal;

channel decoding the channel encoded signal to obtain a cyclic redundancy coded signal;

cyclic redundancy code checking the cyclic redundancy coded signal; and

if the cyclic redundancy coded signal fails the cyclic redundancy code check, examining a unique identifier to determine if the signal is intended for the mobile communication device.

9. The method according to claim 8, wherein receiving further comprises receiving a radio frequency signal for a frame on a forward dedicated control channel.

10. The method according to claim 8, wherein the unique identifier comprises a group identifier that identifies at least one mobile communication device for which the signal is intended.

11. The method according to claim 8, wherein the unique identifier comprises a mobile station identity that identifies a specific mobile communication device for which the signal is intended.

12. The method according to claim 8, wherein the unique identifier is obtained from a set of segments of the scrambled signal.

13. The method according to claim 8, further comprising:

attempting to descramble the scrambled signal using a long code mask;

determining the scrambled signal is unsuccessfully descrambled; and

increasing a signal quality set point if in the examining step it is determined that the signal is intended for the mobile communication device but the scrambled signal is unsuccessfully descrambled.

14. The method according to claim 8, further comprising receiving a radio frequency signal for a frame on a forward dedicated control channel.

15. A method on a network of distinguishing a frame on a channel shared by a plurality of users, the method comprising:

determining a unique identifier for each of a set of mobile communication devices;

obtaining a message intended for one of the mobile communication devices;

scrambling the message using a long code generated using a mobile communication device specific long code mask to obtain a scrambled message;

incorporating the unique identifier into the scrambled message for a frame intended for a selected mobile communication device; and

transmitting the frame.

16. The method according to claim 15, wherein transmitting further comprises transmitting the frame on a forward dedicated control channel.

17. The method according to claim 15, wherein incorporating the unique identifier comprises puncturing the unique identifier into the scrambled message.

18. The method according to claim 15, wherein incorporating the unique identifier comprises puncturing the unique identifier into a set of segments of the scrambled message.

19. The method according to claim 15, wherein the unique identifier comprises a mobile station identity code.

20. The method according to claim 15, wherein the unique identifier comprises a mobile station identity code derived from a mobile station identity number.

21. The method according to claim 15, wherein the unique identifier comprises a mobile station identity code derived from a mobile station identity number by performing block coding on the mobile station identity number.

22. The method according to claim 15, wherein the unique identifier comprises a mobile station identity code derived from a mobile station identity number by performing length 16 Walsh block coding on the mobile station identity number.

23. A method on a network of distinguishing a frame on a channel shared by a plurality of mobile communication devices, the method comprising:

identifying a set of mobile communication devices;

determining a unique identifier for at least one of the set of mobile communication devices;

obtaining information bits intended for the at least one of the mobile communication devices;

appending cyclic redundancy code bits to the information bits to obtain a cyclic redundancy coded message;

performing channel coding on the cyclic redundancy coded message to obtain a channel coded message;

scrambling the channel coded message using a long code generated using a mobile communication device specific long code mask to obtain a scrambled message;

incorporating the unique identifier into the scrambled message for a frame intended for a selected mobile communication device; and

transmitting the frame.

24. The method according to claim 23, wherein transmitting further comprises transmitting the frame on a forward dedicated control channel intended for a selected mobile communication device.

25. The method according to claim 23, wherein incorporating the unique identifier comprises puncturing the unique identifier into a set of segments of the scrambled message.

26. The method according to claim 23, wherein the unique identifier comprises a mobile station identity code derived from a mobile station identity number.

27. The method according to claim 23, wherein the unique identifier comprises a mobile station identity code derived from a mobile station identity number by performing block coding on the mobile station identity number.

28. A communication device comprising:

a receiver configured to receive a radio frequency signal for a frame;

a demodulator coupled to the receiver, the demodulator configured to demodulate the signal to obtain a scrambled signal;

a descrambler coupled to the demodulator, the descrambler configured to descramble the scrambled signal to obtain a descrambled signal; and

a unique identifier match module configured to extract a unique identifier from the received signal and also configured to examine the unique identifier extracted from the received signal to determine if the signal is intended for the communication device.

29. The communication device according to claim 28, further comprising a cyclic redundancy code check module coupled to the descrambler, the cyclic redundancy code check module configured to cyclic redundancy code check the descrambled signal.

30. The communication device according to claim 28, wherein receiver is further configured to receive a radio frequency signal for a frame on a forward dedicated control channel during a broadcast multicast service communication.

31. The communication device according to claim 28, further comprising a power controller,

wherein the descrambler is configured to attempt to descramble the scrambled signal using a long code mask and determine the scrambled signal is unsuccessfully descrambled,

wherein the power controller is configured to increase a received signal quality set point if it is determined that the signal is intended for the mobile communication device but the scrambled signal is unsuccessfully descrambled;

and

decrease the received signal quality set point if in the examining step it is determined that the signal is intended for the communication device but the scrambled signal is successfully descrambled.

32. A network controller comprising:

unique identifier determination module configured to determine a unique identifier for a communication device recipient of a signal;

a scrambler configured to scramble the signal using a long code generated using a communication device specific long code mask to obtain a scrambled signal;

a unique identifier incorporator configured to incorporate the unique identifier into the scrambled signal for a frame intended for the communication device; and

a transmitter configured to transmit the frame.

33. The network controller according to claim 32, wherein the transmitter transmits the frame on a forward dedicated control channel during a broadcast multicast service session.

34. The network controller according to claim 32, wherein the unique identifier incorporator incorporates the unique identifier into the scrambled signal by puncturing the unique identifier into a power control section of the scrambled signal.

35. The network controller according to claim 32, wherein the unique identifier comprises a mobile station identity code derived from a mobile station identity number of the communication device.