Method and apparatus for transmitting and receiving variable rate data

• US 6,798,736 B1
• Filed: 09/22/1998
• Issued: 09/28/2004
• Est. Priority Date: 09/22/1998
• Status: Expired due to Term

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Black, Peter J., Sindhushayana, Nagabhushana T., Karmi, Gadi
• Primary Examiner(s): Pham, Chi
• Assistant Examiner(s): George, Keith M.
• Application Number:
  US09/158,254
• Time in Patent Office: 2,198 Days
• Field of Search: 370/209, 370/468, 370/208, 370/335, 370/342, 375/130, 375/140, 375/145, 375/149, 375/225
• US Class Current: 370/208
• CPC Class Codes: H04B 1/707 using direct sequence modulation
• CPC Class Codes: H04B 2201/70701 featuring pilot assisted reception
• CPC Class Codes: H04B 2201/70703 using multiple or variable rates
• CPC Class Codes: H04J 13/00 Code division multiplex systems for frequency hopping H04B1/713
• CPC Class Codes: H04J 13/0048 Walsh
• CPC Class Codes: H04J 13/10 Code generation
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0025 Transmission of mode-switching indication
• CPC Class Codes: H04L 1/0038 Blind format detection for detection of modulation format H04L27/0012
• CPC Class Codes: H04L 1/08 by repeating transmission, e.g. Verdan system H04L1/1858 and H04L1/189 take precedence

Abstract

A variable rate transmission system transmits a variable rate data packet including an accompanying rate indication signal indicative of the transmission rate of the variable data packet. The data packet can be spread using a long pseudonoise (PN) code, the mask of which can be selected in accordance with the transmission rate of the variable rate data packet. A preamble, providing the transmission rate, can be punctured into an outgoing pilot signal. The rate indication signal can be encoded in accordance with a set of orthogonal functions that are part of the indication of the transmission rate of the data packet.

Claims

1. A method for transmitting a variable rate data packet, comprising:

receiving said variable rate data packet;

encoding said variable rate data packet;

receiving a rate indication signal indicating a transmission rate of said variable rate packet;

encoding said rate indication signal in accordance with a predetermined set of encoding formats wherein the encoding formats are selected in accordance with a value of the rate indication signal;

receiving a rate request message;

encoding said rate request message; and

receiving said encoded variable data rate packet;

covering said encoded variable rate packet in accordance with a first orthogonal covering format;

receiving said encoded rate indication signal; and

covering said encoded rate indication signal in accordance with a second orthogonal covering format.

2. The method of claim 1 wherein said rate indication coding comprises:

selecting a Walsh sequence from a predetermined set of Walsh sequences in accordance with the transmission rate of said variable rate packet;

encoding said rate indication signal in accordance with said selected Walsh sequence.

3. The method of claim 1 further comprising:

encoding a set of pilot symbols to provide a pilot signal; and

combining said encoded rate indication signal and said pilot signal.

4. The method of claim 3, further comprising:

combining said encoded rate request message with said pilot signal and said encoded rate indication signal.

5. A system for transmitting a variable rate data packet, comprising:

data coding means for receiving said variable rate data packet and for encoding said variable rate data packet;

rate indication coding means for receiving a rate indication signal indicating a transmission rate of said variable rate packet and for encoding said rate indication signal in accordance with a predetermined set of encoding formats wherein the encoding formats are selected in accordance with a value of said rate indication signal;

pilot coding means for encoding a set of pilot symbols to provide a pilot signal;

multiplexer means for combining said encoded rate indication signal and said pilot signal; and

rate request coding means for receiving a rate request message, encoding said rate request message and providing said encoded rate request message to said multiplexer means, wherein said multiplexer means combines said encoded rate request message with said pilot signal and said rate indication signal.

6. The variable rate transmission system of claim 5, further comprising:

first orthogonal spreading means for receiving said encoded variable data rate packet and for spreading said encoded variable rate packet in accordance with a first orthogonal covering format; and

second orthogonal spreading means for receiving said encoded rate indication signal and for spreading said encoded rate indication signal in accordance with a second orthogonal covering format.

7. The variable rate transmission system of claim 6, further comprising:

first scrambling means for receiving said orthogonal spread variable rate data packet and for scrambling said orthogonal spread variable rate data packet in accordance with a long code pseudonoise (PN) sequence; and

second scrambling means for receiving said orthogonal spread rate indication signal and for scrambling said orthogonal spread rate indication signal in accordance with said long code pseudonoise sequence.

8. The variable rate transmission system of claim 7, further comprising:

complex PN spreading means for receiving said PN scrambled variable rate data packet and said PN scrambled rate indication signal and for performing a complex PN spreading upon said PN scrambled variable rate data packet and said PN scrambled rate indication signal in accordance with a combination of a first PN sequence and a second PN sequence.

9. A method for transmitting a variable rate data packet, comprising:

receiving said variable rate data packet;

encoding said variable rate data packet;

receiving a rate indication signal indicating a transmission rate of said variable rate packet;

encoding said rate indication signal in accordance with a predetermined set of encoding formats wherein the encoding formats are selected in accordance with a value of the rate indication signal;

encoding a set of pilot symbols to provide a pilot signal;

combining said encoded rate indication signal and said pilot signal;

receiving a rate request message and encoding said message; and

combining said encoded rate request message with said pilot signal and said encoded rate indication signal.

10. The method of claim 9, wherein said rate indication coding comprises:

selecting a Walsh sequence from a predetermined set of Walsh sequences in accordance with the transmission rate of said variable rate packet; and

encoding said rate indication signal in accordance with said selected Walsh sequence.

11. The method of claim 9, further comprising:

receiving said encoded variable data rate packet;

spreading said encoded variable rate packet in accordance with a first orthogonal covering format;

receiving said encoded rate indication signal; and

spreading said encoded rate indication signal in accordance with a second orthogonal covering format.

12. The method of claim 11, further comprising:

receiving said orthogonal spread variable rate data packet;

scrambling said orthogonal spread variable rate data packet in accordance with a long code pseudonoise (PN) sequence; and

receiving said orthogonal spread rate indication signal; and

scrambling said orthogonal spread rate indication signal in accordance with said long code pseudonoise sequence.

13. The method of claim 12, further comprising:

receiving said PN scrambled variable rate data packet and said PN scrambled rate indication signal; and

performing a complex PN spreading upon said PN scrambled variable rate data packet and said PN scrambled rate indication signal in accordance with a combination of a first PN sequence and a second PN sequence.