The influence of adjacent channel interference on FM communication system

Assembling many radio stations in a same vehicle or networking of radios is likely to induce serious self-interference, such as adjacent channel, co-channel and intermodulation interference. This text mainly investigates the adjacent channel interference (ACI) of FM signal. In order to deeply analyze the influence of ACI and White Gaussian noise on FM communication system, a new Hilbert demodulation method of software radio is introduced, and its realization method is deduced in detail. Accordingly, ACI model of FM communication system is established, and the influence of ACI interference is estimated through calculating the distortion of the speech signal demodulated. Finally, some useful conclusions are obtained through comparing the demodulation results of the new Hilbert demodulation and the traditional amplitude frequency discriminator (AFD).