Analog Devices Global

Analog Devices International Unlimited Company

Analog Devices Global Unlimited Company

Peadar Antony Forbes

Patrick Joseph Pratt

Martin McCormick

David J McLaurin

David J Mclaurin

Eamon Nash

Mingming Zhao

Claire Masterson

Ovidiu Vasile Balaj

Martin Steven McCORMICK

Transmitter noise cancellation may be applied on a channel by channel basis to active channels of an incoming radio frequency signal received at a receiver. A noise cancellation filter may be provided for each active channel in a predetermined signal band. Applying noise cancellation on a per active channel basis instead of to the entire receive band may substantially reduce the filtering requirement and number of filter coefficients or taps to save power and reduce manufacturing costs. Channelized transmitter noise cancellers, multi transmitter-receiver cross coupling cancellers, and hybrid full signal band and channelized transmitter noise cancellers are also provided.

Radio frequency transmitter noise cancellation

A method of reducing the noise from a transmitter at an associated receiver is disclosed. Noise contributions in active channels are identified and used to update a shared noise cancellation filter. Excluding signals from inactive channels speeds up the filter convergence to a near optimal solution. Sharing a filter across multiple channels reduces component count and power consumption.

Method of and apparatus for transmit noise reduction at a receiver

Aspects of this disclosure relate to protecting a circuit, such as an amplifier, from transient overdrive events and/or average overdrive events. In one embodiment, an indication of average power, such as root mean squared (RMS) power of a radio frequency (RF) signal, can be compared to a first threshold and an indication of a peak RF power can be compared to a second threshold. When the indication of average power exceeds the first threshold, an average overdrive event can be detected. When the indication of peak power exceeds the second threshold, a peak overdrive event can be detected. If either a transient overdrive event or an average overdrive event is detected, a circuit, such as an amplifier, can be protected.

Power detector with overdrive detection

An all digital model of nonlinear transmitter signal distortion in signals received at a receiver of a transmitter-receiver may be used to estimate distortion. The estimated distortion may then be cancelled from the received signals to improve signal quality of the received signal. The digital nonlinear model may be part of an estimator circuit that estimates nonlinear distortion terms by applying a formula or transformation to a digitized version of the signals transmitter at a transmitter of the transmitter-receiver. A mixer may be used to shift a frequency of the estimated nonlinear terms away from a transmitter frequency so that the nonlinear terms can later be subtracted from the incoming signal received at the receiver at a receiver frequency. Circuits and methods are provided.

All digital transmitter noise correction

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Cloghroe, Ireland

Peadar Antony Forbes