Rake-like Receiver Structures for Unmanned Aerial Vehicle Direct Sequence Spread Spectrum PPM Control Signal

Direct sequence spread spectrum (DS-SS) technique is widely used in modern telecommunications and it represents the latest advancement in radio control signal protection. One of the most widely used unmanned aerial vehicle (UAV) radio control systems is the binary pulse-position modulated (PPM) control system. In this paper, two structures of rake-like receiver for improvement of DS-SS binary PPM UAV control signal reception at low signal-to-noise ratios are proposed and analyzed. Both of them are based on the combining signals obtained from an antenna array: predetection and postdetection combiners are considered. Performance measures of the both structures are calculated. It is shown that rake-like receiver with predetection combiner is superior.