METHOD AND APPARATUS FOR TRANSMITTING AND RECEIVING VARIABLE RATE DATA

• US 20080080363A1
• Filed: 11/15/2007
• Published: 04/03/2008
• Est. Priority Date: 09/22/1998
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Black, Peter, Sindhushayana, Nagabhushana, Karmi, Gadi
• Granted Patent: US 7,961,592 B2
• Time in Patent Office: Days
• US Class Current: 370/209
• 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. An apparatus for transmitting a variable rate user data packet, comprising:

data coding means for encoding and spreading the variable rate user data packet to produce a Walsh covered encoded variable rate user data packet;

wherein the spreading is in accordance with a first Walsh code;

rate indication coding means for encoding a rate indication data, wherein the rate indication data indicates the transmission rate of the variable rate user data packet, to produce an encoded rate indication data;

wherein the data coding means produces the Walsh covered encoded variable rate user data packet in accordance with a rate being indicated by the rate indication data;

multiplexer means for combining the encoded rate indication data and pilot data to produce a control data packet;

means for spreading the control data packet in accordance with a second Walsh code to produce a Walsh covered control data packet;

wherein the first Walsh code and the second Walsh code are orthogonal to each other;

means for scrambling the Walsh covered control data packet and the Walsh covered encoded variable rate user data packet in accordance with a code sequence; and

means for concurrently transmitting the scrambled Walsh covered control data packet and the scrambled Walsh covered encoded variable rate user data packet.

2. The apparatus of claim 1

wherein the transmission of the encoded rate indication data spans over duration of a time frame.

3. The apparatus of claim 2

wherein the encoded rate indication data is punctured into the pilot data at least once in every time slot of the time frame.

4. A method for transmitting a variable rate user data packet comprising:

encoding and spreading the variable rate user data packet to produce a Walsh covered encoded variable rate user data packet;

wherein the spreading is in accordance with a first Walsh code;

encoding a rate indication data, wherein the rate indication data indicates the transmission rate of the variable rate user data packet, to produce an encoded rate indication data;

wherein the Walsh covered encoded variable rate user data packet is produced in accordance with a rate being indicated by the rate indication data;

multiplexing to combine the encoded rate indication data and pilot data to produce a control data packet;

spreading the control data packet in accordance with a second Walsh code to produce a Walsh covered control data packet;

wherein the first Walsh code and the second Walsh code are orthogonal to each other;

scrambling the Walsh covered control data packet and the Walsh covered encoded variable rate user data packet in accordance with a code sequence; and

concurrently transmitting the scrambled Walsh covered control data packet and the scrambled Walsh covered encoded variable rate user data packet.

5. The method of claim 4

wherein the transmission of the encoded rate indication data spans over duration of a time frame.

6. The method of claim 5

wherein the encoded rate indication data is punctured into the pilot data at least once in every time slot of the time frame.

7. An apparatus for receiving a variable rate user data packet transmission, comprising:

means for concurrently receiving a scrambled Walsh covered control data packet and a scrambled Walsh covered encoded variable rate user data packet;

means for de-scrambling the received scrambled Walsh covered control data packet and the received scrambled Walsh covered encoded variable rate user data packet in accordance with a code sequence;

means for de-spreading the de-scrambled control data packet in accordance with a control channel Walsh code to produce a control data packet;

means for de-multiplexing the de-spreaded control data packet to produce received encoded rate indication data and received pilot data;

means for decoding the received encoded rate indication data to produce a rate indication data, wherein the rate indication data indicates the transmission rate of the variable rate user data packet,

means for decoding and de-spreading the de-scrambled Walsh covered encoded variable rate user data packet to produce the variable rate user data packet in accordance with a data channel Walsh code, the rate being indicated by the rate indication data and the received pilot data;

wherein the control channel Walsh code and the data channel Walsh code are orthogonal to each other.

8. The apparatus of claim 7

wherein the reception of the encoded rate indication data spans over duration of a time frame.

9. The apparatus of claim 8

wherein the encoded rate indication data is punctured into the pilot data at least once in every time slot of the time frame.

10. A method for receiving a variable rate user data packet transmission, comprising:

concurrently receiving a scrambled Walsh covered control data packet and a scrambled Walsh covered encoded variable rate user data packet;

de-scrambling the received scrambled Walsh covered control data packet and the received scrambled Walsh covered encoded variable rate user data packet in accordance with a code sequence;

de-spreading the de-scrambled control data packet in accordance with a control channel Walsh code to produce a control data packet;

de-multiplexing the de-spreaded control data packet to produce received encoded rate indication data and received pilot data;

decoding the received encoded rate indication data to produce a rate indication data, wherein the rate indication data indicates the transmission rate of the variable rate user data packet,

decoding and de-spreading the de-scrambled Walsh covered encoded variable rate user data packet to produce the variable rate user data packet in accordance with a data channel Walsh code, the rate being indicated by the rate indication data and the received pilot data;

wherein the control channel Walsh code and the data channel Walsh code are orthogonal to each other.

11. The method of claim 10

wherein the reception of the encoded rate indication data spans over duration of a time frame.

12. The method of claim 11

wherein the encoded rate indication data is punctured into the pilot data at least once in every time slot of the time frame.