Bit error rate of a digital radio eavesdropper on computer CRT monitors

An eavesdropper on computer CRT (cathode ray tube) monitors can be used to intercept video information. Its anti-noise performance is analyzed in this paper. Baseband transmission models of digital signals are established according to the operating principle of the eavesdropper. The relationship between the eavesdropper's bit error rate and some parameters, such as intercept distance, superposition times and noise power, is discussed under the circumstances of ISI and ISI-freedom. Good agreement is obtained between experimental results and theoretical analysis.