Spread spectrum base station notch filtering transmitted signals

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.

1 . A method for spread spectrum code division multiple access (CDMA) communications, the method comprising a personal communications network unit (PCNU):
 generating a spread spectrum code division multiple access (CDMA) data signal using a pseudo random chip code sequence, the spread data signal encompassing a selected range of frequencies;   filtering the spread data signal at frequencies within the selected range; and   transmitting the notch filtered spread data signal.   
   
   
       2 . The method of  claim 1  further comprising:
 determining frequencies currently used that overlap a frequency spectrum of the spread data signal, wherein the notch filtering is at the determined frequencies.   
   
   
       3 . The method of  claim 2  further comprising:
 detecting received signal power associated with the overlapping frequencies;   wherein the determining of the overlapping frequencies is based in part on the detected received signal power.   
   
   
       4 . The method of  claim 2  wherein each of the overlapping frequencies has an associated bandwidth, the method further comprising:
 determining the associated bandwidth for each of the overlapping frequencies, wherein the notch filtering filters a bandwidth at each of the overlapping frequencies based in part on that frequency's determined associated bandwidth.   
   
   
       5 . The method of  claim 2  further comprising:
 receiving a command indicating the overlapping frequencies, wherein the determining of the overlapping frequencies is based in part on the received command.   
   
   
       6 . The method of  claim 1  further comprising:
 receiving a base spread spectrum CDMA data signal and recovering data from the base spread spectrum CDMA data signal, wherein the base spread spectrum CDMA data signal is notched filtered at the frequencies within the selected range.   
   
   
       7 . The method of  claim 6  further comprising:
 notch filtering the received base spread spectrum CDMA data signal at the frequencies within the selected range prior to the recovering of data.   
   
   
       8 . The method of  claim 7  further comprising:
 determining 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 spread spectrum CDMA data signal is at the overlapping frequencies.   
   
   
       9 . The method of  claim 8  further comprising:
 detecting a received signal power associated with the overlapping frequencies wherein the determining of the overlapping frequencies is based in part on the detected received signal power.   
   
   
       10 . The method of  claim 8  wherein each of the overlapping frequencies has an associated bandwidth, the method further comprising:
 determining the associated bandwidth for each of the overlapping frequencies, wherein the notch filtering, of the spread data signal and the base spread spectrum CDMA data signal, filters a bandwidth of each of the overlapping frequencies based in part on that frequency's determined associated bandwidth.   
   
   
       11 . The method of  claim 8  further comprising:
 receiving a command indicating the overlapping frequencies transmitted from a base station, wherein the determining of the overlapping frequencies is based in part on the received command.   
   
   
       12 . A method for spread spectrum code division multiple access (CDMA) communications, the method comprising a personal communications network unit (PCNU):
 mixing a data signal with a pseudo random chip code sequence;   generating a base spread spectrum code division multiple access (CDMA) data signal, the spread data signal encompassing a selected range of frequencies;   notch filtering the spread data signal at frequencies within the selected range; and   transmitting the notch filtered spread data signal.   
   
   
       13 . The method of  claim 12  further comprising:
 detecting a received signal power associated with the frequencies that have a spectrum overlapping a spectrum of the spread data signal;   determining the overlapping frequencies from the detected received signal power, wherein adaptive notch filtering is at the determined frequencies.   
   
   
       14 . The method of  claim 12  further comprising:
 receiving a command indicating the overlapping frequencies and adaptive notch filtering is at the indicated overlapping frequencies.   
   
   
       15 . The method of  claim 12  further comprising:
 controlling an adjustable notch filter.   
   
   
       16 . The method of  claim 12  further comprising:
 modulating the notch filtered spread data signal a radio frequency.   
   
   
       17 . The method of  claim 12  further comprising:
 receiving the base spread spectrum CDMA data signal, wherein the base spread spectrum CDMA data signal is notch filtered at the frequencies within the selected range.   
   
   
       18 . The method of  claim 17  further comprising:
 despreading the base spread spectrum CDMA data signal;   filtering the despread base spread spectrum CDMA data signal; and   detecting data within the despread base filtered data signal.