Advanced Signal Processing Techniques for the Enhancement of Secure Wireless Communication Systems Utilizing Spread-Spectrum Signaling and Smart Antennas

The use of advanced signal processing approaches for improving the performance of secure wireless communication systems utilizing Smart Antennas and Spread Spectrum (SS) signaling is overviewed in this paper,. Emphasis is placed on research results obtained by the author and his research group in the last decade. Using advanced signal processing is shown to highly improve the performance of Smart Antennas and SS techniques in interference limited and wideband multi-user wireless communication systems. The considered advanced signal processing techniques include Artificial Neural Networks (ANN), Wavelets, Higher Order Statistics (HOS) and the related constant Modulus Algorithms (CMA), Genetic Algorithms (GA) and Fractals. In the presentation, the following enhancements of Smart Antenna using modern signal processing techniques are briefly described: i. Using ANN to shape the Array factor, reduce the side-lobe level and affect steerable interference nulling. ii. The use of HOS for blind beamforming and detection of multi-Source multipath signals with general antenna array structures. iii. The use of CMA for mitigating multipath and fading effects. iv. The use of Wavelets in the design of blocking matrix for sidelobe cancellers and for broadband beamforming. v. Using GA for smart and wideband array design. vi. The design of Fractal Arrays for multiband operation On the other hand, the following enhancements of SS signaling using modern signal processing approaches will be highlighted in the presentation: i. The use of ANN for the design of Matched filters (NMF) for efficient code acquisition and in the design multi-user receivers for ii.