The Digital Waveform Generator And Waveform Library Design

Through theoretic analysis of radar signals in the dissertation, we build a waveform library which can generate many kinds of radar signals, and provide references to waveform selection. This waveform library not only contains those typical radar signals like single-carrier frequency signal, encoded signal, LFM etc, but also include many hybrid modulated signals, like FSK/PSK signal, FSK/PPM signal, PSK/PPM signal, pseudo-random FSK/PSK signal, etc. We use Visual C++6.0 to implement this software program, this makes it easy in control operation and provides a nice human-machine interactive interface.Digital waveform generator which use DDS (Direct Digital Synthesize) technology has many merits like high frequency resolution, good stability and easy to generate signal. CPLD (Complex Programmable Logic Device) has superiority at providing high speed and high reliability. Combine this technology with DDS can efficiently break through many bottlenecks in traditional electronic system, and greatly improve system performance. This method can ameliorate digital waveform generator's signal bandwidth, and enhance system's high integration. Here we bring forward one digital waveform generator based on DDS technology, use CPLD to do hardware design, finish functional and timing synthesize with certain EDA tool's help. This paper mainly contains the following four parts :1. Discuss the methods to generate pseudo-random sequences and property of them;2. Use the high-quality pseudo-random sequence to create pseudo-random FSK/PSK signal;3. Use VC to design waveform library;4. Bring forward one DDS-based two-RAM two-channel digital waveform generator which use CPLD technology to improve system's integration.The research background of this paper is based upon the military project named "the waveform research of low probability of interception radar" of the ninth five years plan and extends on it.