Method and apparatus for code division multiple access communication with increased capacity through self-noise reduction

• US 6,324,159 B1
• Filed: 05/06/1999
• Issued: 11/27/2001
• Est. Priority Date: 05/06/1998
• Status: Expired due to Fees

• Current Assignee: Agilent Technologies, Inc.
• Original Assignee: Sirius Communications N.V. (Agilent Technologies, Inc.)
• Inventors: Vanhoof, Jan, Mennekens, Jan, Philips, Lieven, Vandermot, Jurgen, Mertens, Carl
• Primary Examiner(s): Chin, Wellington
• Assistant Examiner(s): Jones, Prenell
• Application Number:
  US09/306,589
• Time in Patent Office: 936 Days
• Field of Search: 370/203, 370/208-211, 370/342, 370/529, 370/487, 375/140-146, 375/152, 375/285, 375/340-348, 375/130, 375/224, 375/150, 455/522, 455/69
• US Class Current: 370/203
• CPC Class Codes: H04B 1/707 using direct sequence modulation
• CPC Class Codes: H04J 13/0022 PN, e.g. Kronecker
• CPC Class Codes: H04J 13/004 Orthogonal
• CPC Class Codes: H04J 13/102 Combining codes
• CPC Class Codes: H04J 13/12 Generation of orthogonal codes

Abstract

A method of generating a waveform with a plurality of orthogonal PN codes for use in a communications network utilizing quasi-synchronous code division multiple access. The orthogonal PN codes modulate multiple data streams together with a non-orthogonal PN code having desirable auto-correlation properties. The result is a complex signal with time-aligned PN codes.

Claims

1. A method to generate a waveform with a plurality of orthogonal PN codes, to modulate a plurality of data streams, together with a non-orthogonal PN-code, having good auto-correlation properties, comprising the steps of:

Taking a plurality of orthogonal codes that are used to spread a plurality of data streams;

combining each of said spread data streams with in-phase BPSK modulations, and performing an addition, after optional gain control of each spread stream to obtain first signals;

Defining a PN-code with good auto-correlation properties, and combining said code with BPSK modulation, which is orthogonal (90 degrees out-of-phase) with said BPSK modulations to obtain second signals;

Combining said first and second signals as a complex signal with time-aligned PN-codes.

2. A method to demodulate said waveform of claim 1, comprising the steps of:

searching the PN Code start of said code with good auto-correlation properties;

Tracking said PN code with good auto-correlation properties;

Despread and demodulate said data streams which are time-aligned with said PN-code with good auto-correlation properties.

3. An apparatus for generating and demodulating of said waveform of claim 1.

4. The apparatus of claim 3, wherein said apparatus is comprised in an Integrated circuit.