Method and apparatus for interference cancellation for a high data rate user in a CDMA system

An apparatus for reducing co-channel interference in a code division multiple access (CDMA) radio telephone system wherein a traffic channel signal is transmitted from a first station in the system to and a second station in the system, comprising:

• (a) means for forming a reduced interference signal at the second station by subtracting an interference signal from the traffic channel signal, wherein the traffic channel signal contains information representative of a plurality of CDMA data signals each of which is modulated with a different Walsh code prior to transmission of the traffic channel signal from the first station to the second station;
• (b) means for forming a decoded signal at the second station by decoding information representative of the reduced interference signal using a decoder that outputs a plurality of metric values;
• (c) means for forming an estimated signal in accordance with the plurality of metric values;
• (d) means for forming the interference signal from the estimated signal, wherein the means for forming the interference signal includes means for forming a plurality of reconstructed CDMA signals from the estimated signal, each of the reconstructed CDMA signals being modulated in accordance with a different one of the Walsh codes.

An apparatus for reducing co-channel interference in a code division multiple access (CDMA) radio telephone system wherein a traffic channel signal is transmitted from a first station in the system to and a second station in the system, comprising:

• (a) a signal subtractor that forms a reduced interference signal at the second station by subtracting an interference signal from the traffic channel signal, wherein the traffic channel signal contains information representative of a plurality of CDMA data signals each of which is modulated with a different Walsh code prior to transmission of the traffic channel signal from the first station to the second station;
• (b) a decoder that forms a decoded signal at the second station by decoding information representative of the reduced interference signal using a decoding algorithm that outputs a plurality of metric values;
• (c) a signal estimator that forms an estimated signal in accordance with the plurality of metric values;
• (d) a signal reconstructor that forms the interference signal from the estimated signal, wherein the signal reconstructor includes at least one modulator for forming a plurality of reconstructed CDMA signals from the estimated signal, each of the reconstructed CDMA signals being modulated in accordance with a different one of the Walsh codes.