Spread spectrum base station notch filtering transmitted signals

• US 7,519,098 B2
• Filed: 02/19/2004
• Issued: 04/14/2009
• Est. Priority Date: 05/15/1991
• Status: Expired due to Fees

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Schilling, Donald L.
• Primary Examiner(s): Harper; Vincent P.
• Assistant Examiner(s): SANTIAGO CORDERO, MARIVELISSE
• Application Number:
  US10/782,165
• Publication Number:
  US 20040160926A1
• Time in Patent Office: 1,881 Days
• Field of Search: 375/130, 375/140, 375/146, 370/342
• US Class Current: 375/130
• CPC Class Codes: H04B 1/71 the interference being narrowband interference
• 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

Abstract

A base station is in a spread spectrum code division multiple access (CDMA) communication system with co-exists with a diverse system of existing users. The diverse system selectively utilizes various frequencies within a selected range of frequencies. The base station generates a plurality of spread spectrum CDMA data signals using pseudo random chip code sequences. The spread data signals encompass the selected range. The base station notch filters the spread data signals at frequencies within the selected range used by the diverse system. The notch filtered spread data signals are transmitted in CDMA cellular radio communications.

Claims

1. A personal communications network unit comprising:

circuitry configured to generate a spread spectrum code division multiple access (CDMA) data signal using a pseudo random chip code sequences the spread data signal encompassing a selected range of frequencies;

circuitry configured to notch filter the spread data signal at frequencies within the selected range; and

a transmitter configured to transmit the notch filtered spread data signal to a base station.

2. The unit of claim 1 further comprising circuitry configured to determine frequencies currently used that have a spectrum overlapping a spectrum of the spread data signal;

wherein the notch filtering is at the determined frequencies.

3. The unit of claim 2 further comprising circuitry configured to detect received signal power associated with the overlapping frequencies;

wherein the determining of the overlapping frequencies is based on in part the detected received power.

4. The unit of claim 2 wherein each of the overlapping frequencies has an associated bandwidth, the unit further comprising:

circuitry configured to determine the bandwidth for each of the overlapping frequencies;

wherein the notch filtering filters a bandwidth at each of the overlapping frequencies based on in part that frequency'"'"'s determined bandwidth.

5. The unit of claim 2 further further comprising:

circuitry configured to receive a command indicating the overlapping frequencies;

wherein the determining of the overlapping frequencies is based on in part the received command.

6. The unit of claim 1 further comprising:

circuitry configured to receive a base spread spectrum CDMA data signal and recover data from the base data signal;

wherein the base data signal being notched filtered at the frequencies within the selected range.

7. The unit of claim 6 further comprising:

circuitry configured to notch filter the received base data signal at the frequencies within the selected range prior to the recovering of data.

8. The unit of claim 7 further comprising circuitry configured to determine frequencies currently used that have a spectrum overlapping a spectrum of the spread data signal and received base CDMA data signal;

wherein the notch filtering of the spread data signal is at the overlapping frequencies and the notch filtering of the received base data signal is at the overlapping frequencies.

9. The unit of claim 8 further comprising circuitry configured to detect a received signal power associated with the overlapping frequencies wherein the determining of the overlapping frequencies is based on in part the detected received signal power.

10. The unit of claim 8 wherein each of the overlapping frequencies has an associated bandwidth, the unit further comprising:

circuitry configured to determine the bandwidth for each of the overlapping frequencies;

wherein the notch filtering of the spread data signal and the base data signal filters a bandwidth of each of the overlapping frequencies based on in part that frequency'"'"'s determined bandwidth.

11. The unit of claim 8 wherein the unit further comprises:

circuitry configured to receive a command indicating the overlapping frequencies transmitted from the base station;

wherein the determining of the overlapping frequencies is based on in part the received command.

12. A personal communications network unit comprising:

a mixer configured to mix a data signal with a pseudo random chip code sequence to generate a spread spectrum code division multiple access (CDMA) data signal, the spread data signal encompassing a selected range of frequencies;

an adaptive notch filter configured to notch filter the spread data signal at frequencies within the selected range; and

an antenna configured to transmit the notch filtered spread data signal.

13. The unit of claim 12 further comprising a sensor configured to detect a received signal power associated with the frequencies that have a spectrum overlapping a spectrum of the spread data signal, the detected received signal power used to determine the overlapping frequencies;

wherein the adaptive notch filtering is at the determined frequencies.

14. The unit of claim 12 wherein the antenna is configured to receive a command indicating the overlapping frequencies and the adaptive notch filtering is at the indicated overlapping frequencies.

15. The unit of claim 12 further comprising a controller operatively coupled to the adjustable notch filter configured to control the adjustable notch filter.

16. The unit of claim 12 further comprising a local oscillator configured to modulate the notch filtered spread data signal to radio frequency.

17. The unit of claim 12 wherein the antenna is configured to receive a base station spread spectrum CDMA data signal;

wherein the base data signal being notch filtered at the frequencies within the selected range.

18. The unit of claim 17 further comprising:

a despreader configured to dispread the base data signal;

a bandpass filter configured to filter the despread base data signal; and

a detector configured to detect data within the despread base filtered data signal.

19. A personal communications network unit comprising:

a modulator configured to convert a data signal into a format suitable for communicating over radio waves;

a spread spectrum modulator configured to spread the converted data signal using a pseudo random code sequence; and

a transmitter configured to transmit the spread data signal over a spectrum encompassing a selected range of frequencies;

whereby at data is recovered from the transmitted spread data signal by notch filtering at the frequencies within the selected range.

20. A base station comprising:

circuitry configured to generate a plurality of spread spectrum CDMA data signals using pseudo random chip code sequences, the spread data signals encompassing a selected range of frequencies;

circuitry configured to notch filter the spread data signals at frequencies within the selected range; and

circuitry configured to transmit the notch filtered spread data signals to personal communication network units.

21. The base station of claim 20 further comprising circuitry configured to determine frequencies currently used that have a spectrum overlapping a spectrum of the spread data signal;

wherein the notch filtering is at the determined frequencies.

22. The base station of claim 21 further comprising circuitry configured to detect a received signal power associated with the overlapping frequencies;

wherein the determining of the overlapping frequencies is based on in part the detected received signal power.

23. The base station of claim 21 wherein each of the overlapping frequencies has an associated bandwidth, the unit further comprising:

circuitry configured to determine the bandwidth for each of the overlapping frequencies;

wherein the notch filtering filters a bandwidth at each of the overlapping frequencies based on in part that frequency'"'"'s determined bandwidth.

24. The base station of claim 20 further comprising:

circuitry configured to receive a plurality of unit spread spectrum CDMA data signals and recovering data from the unit data signals;

wherein the unit data signals being notch filtered at the frequencies within the selected range.

25. The base station of claim 24 further comprising:

circuitry configured to notch filter the received unit data signals at the frequencies within the selected range prior to the recovering of data.

26. The base station of claim 25 further comprising circuitry configured to determine frequencies currently used that have a spectrum overlapping a spectrum of the spread data signals and received unit CDMA data signals;

wherein the notch filtering of the spread data signals is at the overlapping frequencies and the notch filtering of the received unit data signals is at the overlapping frequencies.

27. The base station of claim 26 further comprising circuitry configured to detect a received signal power associated with the overlapping frequencies wherein the determining of the overlapping frequencies is based on in part the detected received signal power.

28. The base station of claim 26 wherein each of the overlapping frequencies has an associated bandwidth, the unit further comprising:

circuitry configured to determine the bandwidth for each of the overlapping frequencies;

wherein the notch filtering of the spread data signal and the base data signal filters a bandwidth of each of the overlapping frequencies based on in part that frequency'"'"'s determined bandwidth.

29. A base station comprising:

a plurality of mixers configured to mix data signals with pseudo random chip code sequences to generate a plurality of spread spectrum CDMA data signals, the spread data signals encompassing a selected range of frequencies;

a plurality of adaptive notch filters configured to notch filter the spread data signals at frequencies within the selected range; and

an antenna configured to transmit to personal communication network units the combined signal.

30. The base station of claim 29 further comprising a sensor configured to detect a received signal power associated with the frequencies that have a spectrum overlapping a spectrum of the spread data signal, the detected received signal power used to determine the overlapping frequencies;

wherein the adaptive notch filtering is at the determined frequencies.

31. The base station of claim 29 further comprising a controller operatively coupled to the adaptive notch filters configured to control the adjustable notch filters to filter at the frequencies used by the diverse communications system.

32. A base station comprising:

a first plurality of mixers configured to mix data signals with pseudo random chip code sequences to generate a plurality of spread spectrum CDMA data signals;

a second plurality of mixers configured to mix the spread data signals with an intermediate frequency (IF) signal as a plurality of IF spread data signals;

a plurality of adaptive notch filters configured to notch filter the IF data signals;

a third plurality of mixers configured to mix the filtered IF data signals with a radio frequency (RF) signal as spread RF data signals;

wherein the spread RF data signals are effectively notch filtered at frequencies within a selected range of frequencies; and

an antenna configured to transmit to personal communication network units the spread RF data signals.

33. The base station of claim 32 further comprising a combiner configured to combine the spread RF data signals prior to transmission.

34. A spread spectrum base station comprising:

circuitry configured to generate a plurality of spread spectrum signals, the spread spectrum signals encompassing a selected frequency spectrum;

circuitry configured to detect frequencies within the selected frequency spectrum by a diverse signal associated with the detected frequencies;

circuitry configured to notch filter the spread spectrum signals so that a transmitted version of the spread spectrum signals is notch filtered at the detected frequencies; and

circuitry configured to transmit the notch filtered spread spectrum signals.

35. The base station of claim 34 wherein the notch filtering is performed at intermediate frequency.

36. The base station of claim 34 wherein the notch filtering is performed at radio frequency.

37. A spread spectrum base station comprising:

a plurality of mixers configured to mix data signals with codes to generate a plurality of spread spectrum signals;

a sensor configured to detect frequencies within a selected frequency spectrum by a diverse signal associated with the detected frequencies;

a plurality of notched filters configured to notch filter the spread spectrum signals so that a transmitted version of the spread spectrum signals is notch filtered at the detected frequencies; and

an antenna configured to transmit the notch filtered spread spectrum signals.

38. The base station of claim 37 wherein the notch filtering is performed at intermediate frequency.

39. The base station of claim 37 wherein the notch filtering is performed at radio frequency.