Active noise cancellation with FPGA - practical considerations

Active noise cancellation (ANC) has been successfully applied to mitigate noise in many applications, such as in headphones. Besides algorithm development and computer simulation, developing an ANC system involves many practical considerations. From hardware selection to fixed-point implementation, many practical constraints can prevent a good algorithm from functioning properly on the hardware. This paper discusses the development of an ANC prototype system using Field-Programmable Gate Array (FPGA) hardware. The paper also reviews several practical issues that were encountered in the development of the prototype, the symptom and root cause of each issue, and the solutions to mitigate them. The final ANC prototype system successfully cancels noise of both tonal and broadband contents.