Integrated audio and automotive signal processing system
An integrated acoustical signal processing system, which provides adaptive noise cancellation (ANC) and acoustic echo cancellation (AEC) for handsfree cellular phones and adaptive active noise control (AANC) inside automobile passenger Compartments, is developed based on the TMS320C30 digital signal processor. This system provides high quality (noise-free and echo-free) full-duplex voice communication and reduces the acoustic noise inside the automobile. The integration of this system with the existing audio system reduces the overall system cost. In the integrated system, the signals picked up by the error sensors become interference to the AANC system. Musical interference suppression (MIS) is used both for canceling the interfering signal and for partial on-line modeling o f the secondary' paths in the AANC system. The noise interference and acoustic echo problem associated with the hands-free cellular phone (HFCP) system are solved by using the ANC and AEC respectively. An analysis of AEC working in the presence of noise is made to show the significance of ANC in HFCP system. Computer simulations and real-time experiment results are then presented to show the performance of the developed integrated system.