High-data-rate supplemental channel for CDMA telecommunications system

• US 6,501,787 B1
• Filed: 07/26/2000
• Issued: 12/31/2002
• Est. Priority Date: 01/15/1997
• Status: Expired due to Term

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Tiedemann, Edward G. Jr., Jou, Yu-Cheun, Odenwalder, Joseph P., Antonio, Franklin P.
• Primary Examiner(s): Bocure, Tesfaldet
• Application Number:
  US09/625,775
• Time in Patent Office: 888 Days
• Field of Search: 375/130, 375/146, 375/140, 375/147, 370/342, 370/335, 370/209, 455/522
• US Class Current: 375/147
• CPC Class Codes: H04B 1/707 using direct sequence modulation
• CPC Class Codes: H04B 7/264 for data rate control
• CPC Class Codes: H04J 13/0003 Code application, i.e. aspects relating to how codes are applied to form multiplexed channels
• CPC Class Codes: H04J 13/0048 Walsh
• CPC Class Codes: H04L 1/0041 Arrangements at the transmitter end
• CPC Class Codes: H04L 1/0059 Convolutional codes
• CPC Class Codes: H04L 1/0067 Rate matching H04L1/0013 and H04L1/08 take precedence
• CPC Class Codes: H04L 1/08 by repeating transmission, e.g. Verdan system H04L1/1858 and H04L1/189 take precedence
• CPC Class Codes: H04L 2001/0093 Point-to-multipoint

Abstract

A novel and improved method for implementing a high-transmission-rate over-the-air interface is described. A transmit system provides an in-phase channel set and a quadrature-phase channel set. The in-phase channel set is used to provide a complete set of orthogonal medium rate control and traffic channels. The quadrature-phase channel set is used to provide a high-rate supplemental channel and an extended set of medium rate channels that are orthogonal to each other and the original medium rate channels. The high-rate supplemental channel is generated over a set of medium rate channels using a short channel code. The medium rate channel are generated using a set of long channel codes.

Claims

1. A method for operating a multichannel communication system using direct sequence spread spectrum signal processing comprising the steps of:

a) generating a complex data source having a multichannel term and a high-rate term;

b) generating a complex spreading code having an in-phase term and quadrature-phase term;

c) complex multiplying said complex data source and said complex spreading code yielding a real term and an imaginary term;

d) modulating said real term with an in-phase carrier; and

e) modulating said imaginary term with a quadrature-phase carrier.

2. An apparatus for generating channels, comprising:

an in-phase channel generation system for generating an in-phase channel set of medium rate channels;

a quadrature phase channel generation system for generating a quadrature channel set comprising at least one high speed channel that is orthogonal to the in-phase channel set; and

a complex multiplier for combining the in-phase channel set and the quadrature channel set to form an in-phase term and a quadrature phase term.

3. The apparatus in accordance with claim 2 wherein said in-phase channel generation system is comprised of a set of long channel code modulators.

4. The apparatus in accordance with claim 3 wherein said quadrature phase channel generation system is comprised of a short channel code modulator.

5. A receive processing system, comprising:

an antenna for receiving RF signals;

an in-phase carrier coupled to the antenna, for downconverting the RF signals and generating digitized in-phase receive samples;

a quadrature-phase carrier coupled to the antenna, for downconverting the RF signals and generating digitized quadrature-phase receive samples;

an in-phase spreading code generator for generating an in-phase pseudo-random noise (PN) spreading code;

a quadrature-phase spreading code generator for generating a quadrature pseudo-random noise spreading code;

a multiply module coupled to the in-phase carrier, the in-phase spreading code generator, the quadrature-phase carrier, and the quadrature-phase spreading code generator, for multiplying the digitized in-phase receive samples and the digitized quadrature-phase receive samples with a complex conjugate of the PN spreading codes generated by in-phase spreading code generator and quadrature-phase spreading code generator, and generating terms Y_I and Y_Q;

a Walsh generator that generates a Walsh_S code;

a modulator for modulating the receive terms Y_I and Y_Q with the Walsh_S code to generate modulated Y_I and Y_Q data, respectively;

a first summer for summing the modulated Y_I data over the number of Walsh symbols in the Walsh_S code to generate a first summed output;

a second summer for summing the modulated Y_Q data over the number of Walsh symbols in the Walsh_S code to generate a second summed output;

a first pilot filter for summing and filtering the modulated Y_I data to generate a first pilot filtered data; and

a second pilot filter for summing the modulated Y_Q data to generate a second pilot filtered data.

6. The receive processing system of claim 5, further comprising a multiplier that multiplies the first summed output and the second summed output with a complex conjugate of the pilot filtered data.

7. A method for processing a high-rate supplemental channel, comprising:

receiving RF signals;

downconverting the RF signals and generating digitized in-phase receive samples;

downconverting the RF signals and generating digitized quadrature-phase receive samples;

generating an in-phase pseudo-random noise (PN) spreading code;

generating a quadrature-phase pseudo-random noise spreading code;

multiplying the digitized in-phase receive samples and the digitized quadrature-phase receive samples with a complex conjugate of the PN spreading codes, thereby yielding receive terms Y_I and Y_Q;

generating a Walsh_S code;

modulating the receive terms Y_I and YQ with the Walsh_S code to generate modulated Y_I and Y_Q data, respectively;

summing the modulated Y_I data over the number of Walsh symbols in the Walsh_S code to generate a first summed output;

summing the modulated Y_Q data over the number of Walsh symbols in the Walsh_S code to generate a second summed output;

summing and filtering the modulated Y_I data to generate a first pilot filtered data; and

summing the modulated Y_Q data to generate a second pilot filtered data.

8. The method of claim 7 further comprising multiplying the first summed output and the second summed output with a complex conjugate of the pilot filtered data.