Integrated Radar System Of High-speed Communications Technology Research

With the development of the computer technology, modern warfare combat platform faces more and more threats, in which case, every country has to equip its combat platform with more and more electronic devices. But the increasing number of electronic devices will affect the operational flexibility and mobility of the platform. In this case, the integration of radar systems came into being. In the integration of radar systems, electronic warfare and communications systems are integrated. These subsystems share some resources, reducing the equipment resources and improve the resource utilization.This paper is a study in the high-speed communications technology of the integration, including how the amplifier non-linear affect the performance of digital modulations, the noncoherent demodulation of GMSK, the Serially Concatenated GMSK and the Single Carrier Frequency Domain Equalization of GMSK.In order to obtain a large transmit power, the power amplifiers of the radar system always works in the deep saturation region, resulting in nonlinear distortion of the signal and affecting the correctly received of communication system. First the paper analyzes and simulates the effects of power amplifier nonlinear distortion based on Ghorbani model for solid-state amplifier. The results prove that the GMSK signal is less affected by nonlinear distortion and can be applied to the communication of the integration. Then the paper studies the GMSK modulation and demodulation algorithm, including the noncoherent demodulation algorithm in the Gaussian channel and fading channel and the effect of frequency offset. Then the paper focuses on GMSK with serially iterative decoding of convolutional coding (SCGMSK) algorithm.The SCGMSK algorithm performances very well. Then the paper proposes a non-coherent demodulation algorithm of SCGMSK, which only loses 1.5dB in the bit error rate of 10-4 but not sensitive to carrier frequency offset. Finally, the single-carrier frequency-domain equalization (SC-FDE) technique of GMSK signal is appled to weaken the effects by multipath fading. In order to make the frequency-domain equalization technique applied well for GMSK, the GMSK signals need a linear decomposition, and the sender must keep the phase continuous.