Patent ID: 8238860
Filing Date: 2012-08-07
Classification: H04B

Abstract:
1. A circuit for tuning a second order intercept point (IP 2 ) of a mixer to minimize second order intermodulation distortion (IMD 2 ) in a receiver of a transceiver, comprising: means for generating a normally-transmitted two-level PN DSSS signal; means for producing a specially-generated four-level PN DSSS signal whose squared version thereof has a low correlation with the normally-transmitted two-level PN DSSS signal; means for squaring the specially-generated four-level PN DSSS signal; means for transmitting the specially-generated four-level PN DSSS signal; means for attenuating the transmitted signal; means for receiving the attenuated transmitted signal; means for causing IMD means for correlating codewords of the two-level PN DSSS signal produced by the IMD means for changing an operating parameter of the mixer to change an IP means for determining composite power in chips of each correlated codeword at a plurality of operating parameters; and means for determining the operating parameter of the mixer that produces a maximum composite power, thereby tuning the IP