Feature Quantity for Universal Receivers to Identify Protocols of Radio Services and Devices

A number of radio protocols have been developed but still new radio protocols will be developed to satisfy emerging requirements in terms of data transmission speed, power saving, etc. We define the universal receiver as the system that identifies each signal source protocol and that runs a virtual receiver constructed by Software-Defined Radio (SDR) technologies corresponding to the protocol. The input radio information to the universal receiver might include the signals from different sources which use the same bandwidth. Conventional method to decide whether the target bandwidth is used as in cognitive radio systems cannot be applied to the identification of protocols used by the signals from different sources over the same bandwidth. In this paper, we propose a feature quantity of radio signals called "spectrogram form" representing the individual signal source information in terms of time, frequency, and strength distribution. We conducted experimental spectrogram form evaluation identifying radio frequency identification tags\´ protocols. The results indicate that the protocol identification performance of the proposed feature quantity is equal to that of the conventional feature quantity in the case of only one signal source. It is also indicated that the protocols of signals superimposed in the same bandwidth can be identified using the spectrogram form.