Polarization enhanced CDMA communication system

• US 6,061,336 A
• Filed: 09/30/1997
• Issued: 05/09/2000
• Est. Priority Date: 09/30/1997
• Status: Expired due to Term

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Baker, Kenneth R.
• Primary Examiner(s): Kizou, Hassan
• Assistant Examiner(s): SLAVITT, MITCHELL R
• Application Number:
  US08/941,147
• Time in Patent Office: 952 Days
• Field of Search: 370/320, 370/335, 370/342, 455/101, 455/102, 455/103, 455/504, 455/506, 455/132, 455/137, 455/139, 455/277.1, 455/275
• US Class Current: 370/320
• CPC Class Codes: H04B 7/10 Polarisation diversity; Directional diversity

Abstract

The present invention is a novel and improved method and apparatus for transmitting and receiving code division multiple access (CDMA) signals. In a described embodiment of the invention, the radio frequency (RF) signals are received through a first polarization RF unit and a second polarization RF unit generating right slant samples and left slant samples. The right slant samples and the left slant samples are each searched and multipath processed independently and the resulting sets of soft decision data combined and decoded. In a preferred embodiment of the invention, right slant and left slant instances of the signal are generated and transmitted to increase the likelihood of differently polarized instances of the signal being available at the receive system.

Claims

1. A method for transmitting a signal via a code division multiple access communication system comprising:

a) transmitting a first polarized version of said signal from a first antenna; and

b) transmitting a second polarized version of said signal from a second antenna;

wherein said first polarized version of said signal is transmitted with a different polarization and a different directional orientation than said second polarized version of said signal.

2. The method as set forth in claim 1 wherein said first polarized version is orthogonal to said second polarized version.

3. The method as set forth in claim 1 wherein said first polarized version of said signal is at a different time offset than said second polarized version of said signal.

4. A system for receiving a signal received via a set of multipath copies comprising:

a first polarized reception system for generating a first polarized set of said multipath copies in response to said set of multipath copies;

a second polarized reception system for generating a second polarized set of said multipath copies in response to said set of multipath copies; and

a first demodulation system for generating first soft decision data in response to said first polarized set of multipath copes and said second polarized set of multipath copes; and

a second demodulation system for generating second soft decision data in response to said first polarized set of multipath copes and said second polarized set of multipath copes.

5. The system as set forth in claim 4 further comprising a searcher for identifying the time offset of particular multipath copies in said first polarized set of multipath copes and said second polarized set of multipath copies.

6. The system as set forth in claim 5 wherein said searcher is further for configuring said first demodulation system and said second demodulation system to modulate either said first polarized set of multipath copes or said second polarized set of multipath copes.

7. A system for transmitting a code division multiple access signal comprising:

a first radio frequency processing unit for transmitting a first polarized version of said signal via a first antenna; and

a second radio frequency processing unit for transmitting a second polarized version of said signal via a second antenna;

wherein said first polarized version of said signal is transmitted with a different polarization and a different directional orientation than said second polarized version of said signal.

8. The system as set forth in claim 7 wherein said first polarized version is orthogonal to said second polarized version.

9. The system as set forth in claim 7 wherein

said first radio frequency processing unit transmits said a first polarized version of said signal with a first time offset;

and

said second radio frequency processing unit transmits said a second polarized version of said signal with a second time offset that is different from said first time offset.