08175535 is referenced by 187 patents and cites 35 patents.

Active transmitter leakage cancellation techniques are disclosed, for reducing transmitter leakage in a frequency-duplexing radio transceiver. Reducing transmitter leakage to the receiver path of a duplex transceiver eases the linearity requirements for low-noise amplifier and mixer circuits, potentially reducing transceiver cost as well as complexity. In an exemplary method, a radio-frequency (RF) cancellation signal is generated from a transmitter signal, and the RF cancellation signal is combined with a received RF signal to obtain a combined RF signal comprising a residual transmitter leakage component. The residual transmitter leakage component of the combined RF signal is converted, using, e.g., a frequency mixer, to obtain a down-converted signal at baseband or at an intermediate frequency. A magnitude of the residual transmitter leakage component is detected from the down-converted signal, and used to adjust the phase or amplitude of the RF cancellation signal, or both, to reduce the residual transmitter leakage component.

Active cancellation of transmitter leakage in a wireless transceiver
Application Number
Publication Number
8175535 (B2)
Application Date
February 27, 2008
Publication Date
May 8, 2012
Fenghao Mu
Coats & Bennett P L L C
Telefonaktiebolaget LM Ericsson
H04B 1/10
H04B 17/00
H04B 1/00
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