Cellular CDMA notch filter

• US 20060176868A1
• Filed: 03/27/2006
• Published: 08/10/2006
• Est. Priority Date: 12/05/1990
• Status: Abandoned Application

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Schilling, Donald L.
• Application Number:
  US11/389,743
• Publication Number:
  US 20060176868A1
• Time in Patent Office: Days
• US Class Current: 370/342
• CPC Class Codes: G01S 13/82 wherein continuous-type signals are transmitted
• CPC Class Codes: G01S 5/0036 of measured values, i.e. measurement on mobile and position calculation on base station
• CPC Class Codes: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location
• CPC Class Codes: H04B 1/71 the interference being narrowband interference
• CPC Class Codes: H04B 1/7101 with estimation filters
• CPC Class Codes: H04B 1/7102 with transform to frequency domain
• CPC Class Codes: H04B 7/18547 for geolocalisation of a station position fixing by direction or distance determination G01S5/00
• CPC Class Codes: H04B 7/216 Code division or spread-spectrum multiple access [CDMA, SSMA]
• CPC Class Codes: H04B 7/2628 using code-division multiple access [CDMA] or spread spectrum multiple access [SSMA] H04B7/2618 takes precedence
• CPC Class Codes: H04B 7/2631 for broadband transmission
• CPC Class Codes: H04J 13/00 Code division multiplex systems for frequency hopping H04B1/713
• CPC Class Codes: H04W 4/18 Information format or content conversion, e.g. adaptation by the network of the transmitted or received information for the purpose of wireless delivery to users or terminals
• CPC Class Codes: H04W 52/343 taking into account loading or congestion level
• CPC Class Codes: H04W 52/346 distributing total power among users or channels
• CPC Class Codes: H04W 84/042 Public Land Mobile systems, e.g. cellular systems
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

A notch filtering apparatus comprises an input configured to receive at least one cellular code division multiple access (CDMA) signal. Each received cellular CDMA signal has an associated spread bandwidth. A notch filter device is configured to attenuate a bandwidth at a plurality of frequencies within the associated spread bandwidth of the at least one received cellular CDMA signal.

Claims

1. A receiving apparatus comprising:

an antenna receiving at least one cellular code division multiple access (CDMA) signal, each received cellular CDMA signal having an associated spread bandwidth; and

a notch filter device configured to attenuate a bandwidth at a plurality of frequencies within the associated spread bandwidth of the at least one received cellular CDMA signal.

2. The receiving apparatus of claim 1 wherein the attenuated bandwidth at each of the plurality of frequencies does not exceed 30 kHz.

3. The receiving apparatus of claim 1 wherein the attenuated bandwidth at each of the plurality of frequencies is not less than 6 kHz.

4. The receiving apparatus of claim 1 wherein the attenuated bandwidth at each of the plurality of frequencies is in a range from 6 kHz to 30 kHz.

5. The receiving apparatus of claim 4 wherein the associated spread bandwidth does not exceed 10 MHz.

6. The receiving apparatus of claim 1 wherein the notch filtering device is a component of a mobile unit cellular CDMA receiver system.

7. The receiving apparatus of claim 6 wherein the cellular CDMA receiver system is a component of a cellular base station.

8. The receiving apparatus of claim 1 wherein the receiving apparatus is configured to receive signals in a time division multiple access (TDMA) format.

9. The receiving apparatus of claim 1 further comprising a down converter for converting the at least one cellular CDMA signal to an intermediate frequency (IF) signal and providing the IF signal to the notch filter.

10. The receiving apparatus of claim 1 further comprising a despreader for despreading an output of the notch filter device.

11. A method comprising:

receiving at least one cellular code division multiple access (CDMA) signal, each received cellular CDMA signal having an associated spread bandwidth; and

attenuating a bandwidth at a plurality of frequencies within the associated spread bandwidth of the at least one received cellular CDMA signal.

12. The method of claim 11 wherein the attenuated bandwidth at each of the plurality of frequencies does not exceed 30 kHz.

13. The method of claim 11 wherein the attenuated bandwidth at each of the plurality of frequencies is not less than 6 kHz.

14. The method of claim 11 wherein the attenuated bandwidth at each of the plurality of frequencies is in a range from 6 kHz to 30 kHz.

15. The method of claim 14 wherein the associated spread bandwidth does not exceed 10 MHz.

16. The method of claim 11 where the method is performed by a component of a cellular CDMA receiver system.

17. The method of claim 16 wherein the method is performed by a cellular CDMA receiver system which is a component of a cellular base station.

18. The method of claim 11 further comprising receiving signals in a time division multiple access (TDMA) format.

19. The method of claim 11 further comprising converting the at least one cellular CDMA signal to an intermediate frequency (IF) signal and the attenuating is performed on the IF signal.

20. The method of claim 11 further comprising despreading a result of the attenuating.

21. A notch filtering apparatus comprising:

an input configured to receive at least one cellular code division multiple access (CDMA) signal, each received cellular CDMA signal having an associated spread bandwidth; and

a notch filter device configured to attenuate a bandwidth at a plurality of frequencies within the associated spread bandwidth of the at least one received cellular CDMA signal.

22. The notch filtering apparatus of claim 21 wherein the attenuated bandwidth at each of the plurality of frequencies does not exceed 30 kHz.

23. The notch filtering apparatus of claim 21 wherein the attenuated bandwidth at each of the plurality of frequencies is not less than 6 kHz.

24. The notch filtering apparatus of claim 21 wherein the attenuated bandwidth at each of the plurality of frequencies is in a range from 6 kHz to 30 kHz.

25. The notch filtering apparatus of claim 24 wherein the associated spread bandwidth does not exceed 10 MHz.

26. The notch filtering apparatus of claim 21 wherein the notch filtering device is a component of a cellular CDMA receiver system.

27. The notch filtering apparatus of claim 26 wherein the cellular CDMA receiver system is a component of a cellular base station.