Design And Implementation Of Low-interception Hybrid Spread Spectrum Transmitter

Hybrid spread spectrum system that consists of direct sequence spread spectrum,M-ary spread spectrum and frequency hopping can achieve strong resistance tointerception and interference. This thesis completes scheme and hardware platformdesign of the low-interception hybrid spread spectrum transmitter, as well as FPGAimplementation of related modules. The main contents are as follows:1. Principle of hybrid spread spectrum system is introduced in detail; simulationof the M-ary spread spectrum system with RS error-correction coding is given.The realization of high-speed signal filtering using polyphase filter technique ispresented. Approach to realization of broadband, high-speed basebandfrequency hopping based on orthogonal modulation technique and direct digitalfrequency synthesis (DDS) technique is proposed.2. The thesis presents implementation scheme and hardware platform design ofthe whole system. Relevant devices are selected carefully and circuitrydebugging is completed.3. Related modules are implemented by FPGA, including data framing, M-aryspread spectrum, polyphase filter, digital orthogonal modulation, frequencyhopping and communication interface between FPGA and peripheral chips.Verification of proposed modules is carried out.4. The thesis completes joint debugging of software and hardware, as well asfunction testing of the transmitter, the results show that the performance oftransmitter can reach the design targets.