Frequency agile RF feedforward noise cancellation system

Roussel, Alain; Nicholls, Charles; Wight, J.S.

doi:10.1109/rws.2008.4463440

Cited by 18 publications

(5 citation statements)

References 8 publications

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“…The FABSF extends previous work on a feedforward noise cancellation system (FFCS) concept [1,2]. While the FFCS consisted of a single noise cancellation loop intended to make use of miniature fixed-frequency band-reject SAW filters; the FABSF incorporates two transmit-signal cancellation loops to provide a passband characteristic, and protect sensitive noise circuits from the high-power transmit signal.…”

Section: Introductionmentioning

confidence: 92%

Frequency agile bandstop filter (FABSF)

Roussel

Nicholls

Wight

2008

2008 IEEE MTT-S International Microwave Symposium Digest

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The frequency agile bandstop filter (FABSF) is an RF system component that functions as a frequency agile tunable notch filter capable of rejecting the low-level noise in presence of a high-level signal such as the out-of-band noise at the output of a high-power amplifier.The FABSF finds application in a frequency agile duplexer (FAD) system architecture to be implemented in the RF front-end of frequency division duplex (FDD) radio.Index Terms -Flexible radio, base station, tunable filter, feedforward cancellation, frequency agile duplexer.

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Section: Introductionmentioning

confidence: 92%

Frequency agile bandstop filter (FABSF)

Roussel

Nicholls

Wight

2008

2008 IEEE MTT-S International Microwave Symposium Digest

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“…There are several active interference cancelling systems employing feed‐forward techniques [10, 11]. Safarian et al .…”

Section: Interference Cancellationmentioning

confidence: 99%

Adaptive interference cancellation using a sampled analogue signal processor

Rivet

Veyrac

Deval

et al. 2016

IET Radar, Sonar & Navigation

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“…However, frequency agile high-Q filters with low insertion loss would be required to sufficiently attenuate the large transmitter signals, which, in some cases, have output powers of +47dBm (50W) [10]; a difficult and costly challenge. The scheme was targeted at defense applications but is commercially unfeasible for many wireless service providers.…”

Section: Introductionmentioning

confidence: 99%

Mitigation of Reverse Intermodulation Products at Colocated Base Stations

Ahmed

Faulkner

2013

IEEE Trans. Circuits Syst. I

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Abstract-In a colocated setting, large jamming signals from one transmitter can radiate into the antenna system of a second transmitter. The signals enter the second transmitter in the reverse direction and mix in the output stage of its power amplifier to produce intermodulation products. These 'reverse' intermodulation products get radiated from the antenna system and may fall on the victim receiver's desired channel. The paper proposes an architecture that regenerates an estimate of the reverse intermodulation products using the fundamental jammer components and mitigates them in a baseband postdistortion cancellation circuit. A novel multiple-front-end receiver architecture is developed to overcome the high sample rate requirements if the jammers are well out of band. However, this leads to a frequency offset problem in the regenerated distortion estimate. Signal correlation is used to align the frequency, phase and amplitude of the distortion estimate with the interfering reverse intermodulation product. Simulations and theoretical analysis show the output signal-to-interference ratio (SIR) of the system is independent of the input SIR but dependent on the equivalent number of uncorrelated samples in the averaging block. A hardware prototype demonstrated a 16dB reduction of the interfering reverse intermodulation product.

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Frequency agile RF feedforward noise cancellation system

Cited by 18 publications

References 8 publications

Frequency agile bandstop filter (FABSF)

Frequency agile bandstop filter (FABSF)

Adaptive interference cancellation using a sampled analogue signal processor

Mitigation of Reverse Intermodulation Products at Colocated Base Stations

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