We have proposed an intruder detection method by using Multiple Input Multiple Output (MIMO) channel. Although the channel capacity on the MIMO transmission is severely degraded in time variant channels, we can take
advantage of this feature MIMO Sensor applications. We have already demonstrated the effectiveness of MIMO sensor using wireless LAN signals at 2.4GHz band. On the other hand, the transceiver should be simplified from a point of view on power saving. In this paper, we deal a narrowband modulation signals which are used in RF-ID and so on, and propose a signal
synchronization method for the channel estimation using the narrowband MSK and OQPSK signal. Moreover, the basic performance by the proposed channel estimation method is verified when considering the intruder detection by MIMO sensor.