Directional Modulation with Direct Sequence Spread Spectrum Based on Farrow Structure Time-delay Filter

In order to improve the anti-interception capability of directional modulation (DM) system, this paper introduces the direct sequence spread spectrum (DSSS) technology into DM system, and meanwhile proposes to use the Farrow structure time-delay filter to address the aperture effects in DSSS-DM system. Specifically, we first theoretically analyze the impact of the aperture effect on the system, which shows that traditional DM system cannot ensure the DSSS signals to be transmitted without distortion. To this end, a Farrow structure time-delay filter is designed to compensate the aperture effect. Numerical results demonstrate that the proposed solution can effectively alleviate the aperture effect, and 5dB performance gain over traditional DM system is shown when bit error rate equals 10
⁻³
.