Cancellation of pilot and traffic signals
First Claim
1. A method for removing an unwanted signal from a received signal, the method comprising:
- receiving a code division multiple access (CDMA) signal from a transmitter over an air interface, wherein the CDMA signal includes a desired traffic signal and an unwanted traffic signal, the desired traffic signal is spread with a desired traffic spreading code, and the unwanted traffic signal is spread with an unwanted traffic spreading code;
despreading the received CDMA signal with a complex conjugate of the desired traffic spreading code to generate a desired traffic de-spread signal;
generating an unwanted traffic signal cancellation component by generating a correlation of the unwanted traffic spreading code and a complex conjugate of the desired traffic spreading code and scaling the correlation with an unwanted traffic signal strength and unwanted traffic data; and
subtracting the unwanted traffic signal cancellation component from the desired traffic de-spread signal.
0 Assignments
0 Petitions
Accused Products
Abstract
A method for removing selected signals from a received signal prior to decoding begins by receiving communication signals from a transmitter over a CDMA air interface. The received communication signals are input to a traffic signal cancellation system for canceling unwanted traffic signals, thereby producing an output (O). The received communication signals are input to a pilot signal cancellation system for removing a global pilot signal, thereby producing an output (Oadd). The output (Oadd) of the pilot signal cancellation system is subtracted from the output (O) of the traffic signal cancellation system to provide a cancellation system output.
43 Citations
8 Claims
-
1. A method for removing an unwanted signal from a received signal, the method comprising:
-
receiving a code division multiple access (CDMA) signal from a transmitter over an air interface, wherein the CDMA signal includes a desired traffic signal and an unwanted traffic signal, the desired traffic signal is spread with a desired traffic spreading code, and the unwanted traffic signal is spread with an unwanted traffic spreading code; despreading the received CDMA signal with a complex conjugate of the desired traffic spreading code to generate a desired traffic de-spread signal; generating an unwanted traffic signal cancellation component by generating a correlation of the unwanted traffic spreading code and a complex conjugate of the desired traffic spreading code and scaling the correlation with an unwanted traffic signal strength and unwanted traffic data; and subtracting the unwanted traffic signal cancellation component from the desired traffic de-spread signal. - View Dependent Claims (2, 3, 4)
-
-
5. An apparatus for removing an unwanted signal from a received signal, the apparatus comprising:
-
a receiver configured to receive a code division multiple access (CDMA) signal from a transmitter over an air interface, wherein the CDMA signal includes a desired traffic signal and an unwanted traffic signal, the desired traffic signal is spread with a desired traffic spreading code, and the unwanted traffic signal is spread with an unwanted traffic spreading code; a despreader configured to despread the received CDMA signal with a complex conjugate of the desired traffic spreading code to generate a desired traffic de-spread signal; an unwanted traffic signal cancellation component generator configured to generate an unwanted traffic signal cancellation component by generating a correlation of the unwanted traffic spreading code and a complex conjugate of the desired traffic spreading code and scaling the correlation with an unwanted traffic signal strength and unwanted traffic data; and an adder configured to subtract the unwanted traffic signal cancellation component from the desired traffic de-spread signal. - View Dependent Claims (6, 7, 8)
-
Specification