Channel assigning device and method using quasi-orthogonal code in a CDMA communication system

• US 6,504,832 B1
• Filed: 10/19/1999
• Issued: 01/07/2003
• Est. Priority Date: 10/19/1998
• Status: Expired due to Term

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Koo, Chang-Hoi, Kim, Dae-Gyun
• Primary Examiner(s): Kincaid, Lester G.
• Assistant Examiner(s): WASHINGTON, ERIKA ALISE
• Application Number:
  US09/420,320
• Time in Patent Office: 1,176 Days
• Field of Search: 370/342, 370/329, 370/203, 370/208, 370/209, 370/431, 370/335, 370/252, 370/320, 455/450
• US Class Current: 370/342
• CPC Class Codes: H04J 13/0007 Code type
• CPC Class Codes: H04J 13/0048 Walsh
• CPC Class Codes: H04J 13/16 Code allocation
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 72/02 Selection of wireless resources by user or terminal
• CPC Class Codes: H04W 72/0466 the resource being a scrambling code
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 72/541 using the level of interference
• CPC Class Codes: H04W 72/542 using measured or perceived quality

Abstract

A device and method for assigning a channel in a CDMA communication system. According to an embodiment of the present invention, in a channel assigning method for a base station, the base station determines the states of orthogonal codes and quasi-orthogonal code masks when a channel is assigned, selects an available quasi-orthogonal code mask number and orthogonal code index if it is determined that a quasi-orthogonal code should be used, and generates the quasi-orthogonal code. Then, the base station assigns the generated quasi-orthogonal code to a forward link dedicated channel, generates a channel assignment message, and transmits the channel assignment message on a different channel to a mobile station.

Claims

1. A channel assigning method for a base station in a CDMA communication system, comprising the steps of:

determining the states of orthogonal codes and quasi-orthogonal code masks when a channel is assigned, selecting an available quasi-orthogonal code mask and an orthogonal code index if it is determined that a quasi-orthogonal code should be used, and generating the quasi-orthogonal code;

assigning the generated quasi-orthogonal code to a forward link dedicated channel;

generating a channel assignment message including the selected quasi-orthogonal code mask number and the orthogonal code index; and

transmitting the channel assignment message on a different channel to a mobile station.

2. The channel assigning method of claim 1, further comprising the step of generating an available orthogonal code if it is determined that the orthogonal code should be used and assigning the generated orthogonal code to a forward link channel.

3. The channel assigning method of claim 1, wherein it is determined that the quasi-orthogonal code should be used if the number of orthogonal codes in current use reaches an availability limit.

4. The channel assigning method of claim 1, wherein the channel assignment message is transmitted on a paging channel and the quasi-orthogonal channel is assigned to a dedicated channel.

5. The channel assigning method of claim 1, wherein the channel assignment message is transmitted on a dedicated control channel and the quasi-orthogonal code is assigned to a supplemental channel.

6. The channel assigning method of claim 1, wherein the quasi-orthogonal code is generated by adding the selected quasi-orthogonal code mask and orthogonal code.

7. A channel assigning method for a mobile station in a CDMA communication system, comprising the steps of:

receiving a channel assignment message and generating a quasi-orthogonal code corresponding to a quasi-orthogonal code mask number and an orthogonal code index if the quasi-orthogonal code mask number and the orthogonal code index are included in the channel assignment message;

assigning the generated quasi-orthogonal code to a first forward link receiving channel; and

receiving the assigned forward link signal spread by the quasi-orthogonal code using the generated quasi-orthogonal code.

8. The channel assigning method of claim 7, further comprising the step of generating an orthogonal code corresponding to the orthogonal code index, assigning the orthogonal code to a second channel, generating a response message representing the second channel assignment, and transmitting the response message on a reverse link, if the channel assignment message does not include the quasi-orthogonal code information.

9. The channel assigning method of claim 7, wherein the channel assignment message is received on a paging channel and the quasi-orthogonal code is assigned to a dedicated channel.

10. The channel assigning method of claim 7, wherein the channel assignment message is received on a dedicated control channel and the quasi-orthogonal code is assigned to a supplemental channel.

11. A base station communication device in a CDMA communication system, comprising:

a resource configuration database for storing orthogonal code indexes, quasi-orthogonal code mask numbers, and information about the states of orthogonal codes and quasi-orthogonal codes;

a controller for determining whether a quasi-orthogonal code is to be used by determining the states of the orthogonal codes and the quasi-orthogonal code masks, and selecting an available quasi-orthogonal code mask number and orthogonal code index;

a control channel transmitter for generating a channel assignment message including the information about the selected quasi-orthogonal code mask number and orthogonal code index, and transmitting the channel assignment message to a mobile station; and

a channel transmitter for generating a quasi-orthogonal code using the selected orthogonal code and quasi-orthogonal code mask, spreading a channel signal with the quasi-orthogonal code, and transmitting the spread channel signal.

12. The base station communication device of claim 11, wherein if the controller determines that an orthogonal code is to be used, the controller selects an available orthogonal code index from the resource configuration database, and the channel transmitter generates an orthogonal code corresponding to the orthogonal code index, spreads the channel signal with the generated orthogonal code, and transmits the spread channel signal.

13. The base station communication device of claim 12, wherein the controller determines that the quasi-orthogonal code should be used if the number of orthogonal codes in current use reaches a predetermined threshold value.

14. The base station communication device of claim 12, wherein the controller selects an available orthogonal code index in assigning a high priority channel.

15. The base station communication device of claim 11, wherein the control channel transmitter is a paging channel transmitter and the channel transmitter for transmitting the channel signal spread by the quasi-orthogonal code is a dedicated channel transmitter.

16. The base station communication device of claim 11, wherein the control channel transmitter is a dedicated control channel transmitter and the channel transmitter for transmitting the channel signal spread by the quasi-orthogonal code is a supplemental channel transmitter.

17. A mobile station communication device in a CDMA communication system, comprising:

a control channel receiver for receiving a channel assignment message;

a controller for extracting a corresponding quasi-orthogonal code mask number and orthogonal code index from the channel assignment message if the channel assignment message includes the quasi-orthogonal code information; and

a channel receiver for generating a quasi-orthogonal code using an orthogonal code corresponding to the orthogonal code index and a quasi-orthogonal code mask corresponding to the quasi-orthogonal code mask number, and despreading a received channel signal with the generated quasi-orthogonal code.