Device and method for processing a digital data signal in a CDMA radio transmitter

• US 7,583,638 B2
• Filed: 04/08/2002
• Issued: 09/01/2009
• Est. Priority Date: 10/06/1999
• Status: Expired due to Fees

• Current Assignee: Intel Corporation
• Original Assignee: Infineon Technologies AG
• Inventors: Schmidt, Peter, Jung, Peter, Schneider, Michael, Kella, Tideya, Doetsch, Markus, Plechinger, Jörg
• Primary Examiner(s): Trost, IV; William
• Assistant Examiner(s): Nguyen; Toan D
• Application Number:
  US10/117,806
• Publication Number:
  US 20020131385A1
• Time in Patent Office: 2,703 Days
• Field of Search: 370/320, 370/335, 370/341, 370/342, 375/140, 375/146, 375/304, 375/222
• US Class Current: 370/335
• CPC Class Codes: H04B 1/707 using direct sequence modulation
• CPC Class Codes: H04L 27/20 Modulator circuits; Transmitter circuits

Abstract

A device for processing a digital data signal in a CDMA radio transmitter includes a channelization device, a spectral shaping device and a frequency correction device. The channelization device adds a channel-individual CDMA code to the digital data signal, the spectral shaping device subjects the digital, channel-individualized data signal to a spectral shaping and the frequency correction device performs a spectral shift of the digital, spectrally shaped data signal.

Claims

1. A device for processing a digital data signal in a CDMA radio transmitter, comprising:

a channelization device configured to impress a channel-individual CDMA code onto a digital data signal for providing a digital, channel-individualized data signal, said channelization device outputting the digital, channel-individualized data signal at a first signal rate;

a spectral shaping device operatively connected to said channelization device, said spectral shaping device being configured to subject the digital, channel-individualized data signal to a spectral shaping for providing a digital, spectrally shaped data signal, said spectral shaping device outputting the digital, spectrally shaped data signal with a second signal rate, causing the second signal rate to be M times higher than the first signal rate, where M is an integer and M≧

2, the increased second signal rate being caused by sampling each signal component of the digital, channel-individualized data signal multiple times; and

a frequency correction device operatively connected to said spectral shaping device, said frequency correction device being configured to spectrally shift the digital, spectrally shaped data signal.

2. The device according to claim 1, wherein said channelization device uses a CDMA code with a variable spread factor.

3. The device according to claim 1, wherein said channelization device uses a CDMA code with a variable spread factor Q where 4≦

Q≦

512.

4. The device according to claim 1, further including a complex scrambling device provided in a signal path between said channelization device and said spectral shaping device, said complex scrambling device impressing a base station ID onto the digital, channel-individualized data signal.

5. The device according to claim 1, further including a weighting device provided in a signal path upstream of said channelization device, said weighting device multiplying each of a plurality of data symbols in a data string by a weighting factor.

6. A device for processing a digital data signal in a CDMA radio transmitter, comprising:

a channelization device configured to impress a channel-individual CDMA code onto a digital data signal for providing a digital, channel-individualized data signal;

a spectral shaping device operatively connected to said channelization device, said spectral shaping device being configured to subject the digital, channel-individualized data signal to a spectral shaping for providing a digital, spectrally shaped data signal; and

a frequency correction device operatively connected to said spectral shaping device, said frequency correction device being configured to spectrally shift the digital, spectrally shaped data signal, said frequency correction device including a multiplier configured to multiply a narrowband frequency correction sequence onto the digital, spectrally shaped data signal.

7. The device of claim 6, wherein the narrowband frequency correction sequence is configured to compensate for a frequency detuning between the CDMA radio transmitter and a CDMA radio receiver.

8. A device for processing a digital data signal in a CDMA radio transmitter, comprising:

a channelization device configured to impress a channel-individual CDMA code onto a digital data signal for providing a digital, channel-individualized data signal;

a spectral shaping device operatively connected to said channelization device, said spectral shaping device being configured to subject the digital, channel-individualized data signal to a spectral shaping for providing a digital, spectrally shaped data signal; and

a frequency correction device operatively connected to said spectral shaping device, said frequency correction device being configured to spectrally shift the digital, spectrally shaped data signal, said frequency correction device including an arithmetic unit, said arithmetic unit calculating a frequency-corrected, spectrally shaped data signal from the digital, spectrally shaped data signal by running a CORDIC algorithm.

9. A device for processing a digital data signal in a CDMA radio transmitter, comprising:

a channelization device configured to impress a channel-individual CDMA code onto a digital data signal for providing a digital, channel-individualized data signal;

a spectral shaping device operatively connected to said channelization device, said spectral shaping device being configured to subject the digital, channel-individualized data signal to a spectral shaping for providing a digital, spectrally shaped data signal; and

a frequency correction device operatively connected to said spectral shaping device, said frequency correction device being configured to spectrally shift the digital, spectrally shaped data signal;

said channelization device, said spectral shaping device and said frequency correction device being configured as logical switching elements.

10. A method for processing a digital data signal in a CDMA radio transmitter, the method which comprises:

impressing a channel-individual CDMA code onto a digital data signal for providing a digital, channel-individualized data signal;

spectrally shaping the digital, channel-individualized data signal for providing a digital, spectrally shaped data signal; and

performing a frequency correction by spectrally shifting the digital, spectrally shaped data signal, the step of performing the frequency correction including performing a digital frequency correction at a clock rate being Q×

M times higher than a data symbol rate of the digital data signal, where Q is a spread factor of the CDMA code used and M is an integer where M≧

2.

11. A method for processing a digital data signal in a CDMA radio transmitter, the method which comprises:

impressing a channel-individual CDMA code onto a digital data signal for providing a digital, channel-individualized data signal;

spectrally shaping the digital, channel-individualized data signal for providing a digital, spectrally shaped data signal; and

performing a frequency correction by spectrally shifting the digital, spectrally shaped data signal, the step of performing the frequency correction including performing a digital frequency correction by multiplying a narrowband frequency correction sequence onto the digital, spectrally shaped data signal.

12. The method of claim 11, wherein the narrowband frequency correction sequence is configured to compensate for a frequency detuning between the CDMA radio transmitter and a CDMA radio receiver.

13. A method for processing a digital data signal in a CDMA radio transmitter, the method which comprises:

impressing a channel-individual CDMA code onto a digital data signal for providing a digital, channel-individualized data signal;

spectrally shaping the digital, channel-individualized data signal for providing a digital, spectrally shaped data signal; and

performing a frequency correction by spectrally shifting the digital, spectrally shaped data signal, the step of performing the frequency correction including performing a digital frequency correction by running a CORDIC algorithm for calculating a frequency-corrected data signal from the digital, spectrally shaped data signal.

14. A device for processing a digital data signal in a CDMA radio transmitter, comprising:

a channelization device configured to impress a channel-individual CDMA code onto a digital data signal for providing a digital, channel-individualized data signal;

a spectral shaping device operatively connected to said channelization device, said spectral shaping device being configured to subject the digital, channel-individualized data signal to a spectral shaping for providing a digital, spectrally shaped data signal; and

a frequency correction device operatively connected to said spectral shaping device, said frequency correction device being configured to spectrally shift the digital, spectrally shaped data signal, said frequency correction device performing a digital frequency correction at a clock rate being Q×

M times higher than a data symbol rate of the digital data signal, where Q is a spread factor of the CDMA code used and N is an integer where M≧

2.