Method and apparatus for providing variable rate data in a communications system using non-orthogonal overflow channels

• US 7,751,371 B2
• Filed: 07/24/2006
• Issued: 07/06/2010
• Est. Priority Date: 02/28/1995
• Status: Expired due to Fees

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Miller, David S., Zehavi, Ephraim, LaRocca, Judith
• Primary Examiner(s): Ngo; Ricky
• Assistant Examiner(s): NGUYEN, PHUONGCHAU BA
• Application Number:
  US11/492,499
• Publication Number:
  US 20060262756A1
• Time in Patent Office: 1,443 Days
• Field of Search: 370/320, 370/335, 370/342, 370/441, 370/468, 375/200, 375/206, 375/207, 375/130, 375/136, 375/137
• US Class Current: 370/335
• CPC Class Codes: H04B 7/18543 for adaptation of transmission parameters, e.g. power control for detecting or preventing errors in the information received H04L1/00
• CPC Class Codes: H04B 7/216 Code division or spread-spectrum multiple access [CDMA, SSMA]
• CPC Class Codes: H04J 13/0022 PN, e.g. Kronecker
• CPC Class Codes: H04J 13/0048 Walsh
• CPC Class Codes: H04J 13/18 Allocation of orthogonal codes
• CPC Class Codes: H04L 1/0071 Use of interleaving interleaving per se H03M13/27

Abstract

A variable rate transmission system where a packet of variable rate data is transmitted on a traffic channel if the capacity of the traffic channel is greater than or equal to the data rate of the packet. When the rate of the packet of variable rate data exceeds the capacity of the traffic channel, the packet is transmitted on a traffic channel and at least one overflow channel. Also described is a receiving system for receiving and reassembling the data transmitted on the traffic channel and at least one additional overflow channel.

Claims

1. A system for receiving variable rate packets of data symbols comprising:

a traffic demodulator using a first plurality of sequences for demodulating a first half of the variable rate packets, the traffic demodulator having an input and having an output, wherein the first plurality of sequences is orthogonal;

an overflow demodulator using a second plurality of sequences for demodulating a second half of the variable rate packets, the overflow demodulator having an input and having an output, wherein the second plurality of sequences is non-orthogonal to the first plurality of sequences; and

a combiner having a first input coupled to said traffic demodulator output and having a second input coupled to said overflow demodulator output and having an output for producing estimates of ones of said variable rate packets received by said system which include in excess of a predefined number of data symbols.

2. The system of claim 1, wherein the first plurality of sequences is a Walsh code sequence.

3. The system of claim 1 wherein at least one of the variable rate packets is a full rate packet.

4. The system of claim 3 wherein at least one other of the variable rate packets is either an eighth rate packet, a quarter rate packet or a half rate packet.

5. The system of claim 3 further comprising a traffic despreader for despreading the input of the traffic demodulator.

6. The system of claim 5 further comprising an overflow despreader for despreading the input of the overflow demodulator.

7. The system of claim 6 wherein the traffic despreader use a first PN sequence for despreading and the overflow despreader uses a second PN sequence for despreading.

8. The system of claim 7 wherein the first PN sequence is unique from the second PN sequence.