Abstract: A signal transmitted from a switched antenna array with low probability of interception is proposed
to ensure information security in the physical layer transmission. The main idea is that the transmitter
estimates channel information from a training sequence transmitted by the mobile terminal and randomly
selects several antennas for fast switching transmission. Weighting coefficients of each antenna are calculated
according to channel information and the spread-spectrum sequence. Therefore, the signal is a space-spreadspectrum
signal associated with the spread-spectrum sequence and the channel information of each antenna.
In this way, the desired receiver with a single antenna can demodulate the received signal as traditional spreadspectrum
signals, while eavesdroppers cannot extract any useful information from the received signal even if
eavesdroppers know the spread-spectrum sequence of the transmit signal because of the fast switching of the
transmit antenna. Simulation results show that the signal has the same ability of anti-eavesdropping, and has
anti-jamming capability with low probability of detection compared to a reference method.