An approach to analog mitigation of RFI

Summary, in English

Among all noise sources present in wireline transmission systems we focus on one special type: narrowband radio frequency interference generated by radio amateurs (HAM) and broadcast radio stations. This disturbance, characterized by high power and narrow bandwidth, has the potential of overloading the receiver's analog-to-digital converter (ADC). Once the ADC is in saturation, any countermeasure taken in digital domain will fail. A viable way to face this problem is cancellation using the common-mode signal as a reference. This paper describes in detail an adaptive, mixed-signal, narrowband interference canceller employing a modified recursive least-squares algorithm, which is split into an analog and a digital part. The mixed-signal approach enables the circuit to generate an interference-cancelling signal of several MHz while operating the adaptive algorithm at some kilohertz. Simulation as well as measurement results show a steady-state disturbance suppression of about 35 dB. The convergence speed is high enough to protect the ADC from overloading due to time-variant HAM interference.

• Författare: Per Ödling; Per Ola Börjesson; T Magesacher; T Nordstrom
• Avdelning/ar: Institutionen för elektro- och informationsteknik
• Publiceringsår: 2002
• Språk: Engelska
• Sidor: 974-986
• Publikation/Tidskrift/Serie: IEEE Journal on Selected Areas in Communications
• Volym: 20
• Issue: 5
• Länkar: http://dx.doi.org/10.1109/JSAC.2002.1007379
• Dokumenttyp: Artikel i tidskrift
• Förlag: IEEE - Institute of Electrical and Electronics Engineers Inc.
• Ämne: Electrical Engineering, Electronic Engineering, Information Engineering
• Nyckelord: radio frequency interference; cancellation; interference mitigation
• Status: Published
• ISBN/ISSN/Övrigt: ISSN: 1558-0008