Design And Implementation Of A Multi-functional Communication Payload Smart Antenna Processing System

Digital beamforming based smart antennas system can simultaneously form multiply beams with arbitrary patterns and suppress interferences by spatial nulls.Satellite communication payload employing smart antenna technology can effectively increase communication capacity and improve the system anti-interference capability.In this paper,the related key techniques are researched.The software and hardware design scheme,software realization and verification have been accomplished according to the procedure of design,development and testing of the smart antenna processing sub-system.Firstly,the system design scheme of the smart antenna processing sub-system has been accomplished according to the requirements of multiply communication system coexistence,simultaneous multi-band burst communication,fast user acquisition within a wide angle coverage and high-gain beam user tracking in the low-orbit spread spectrum communication system.Broadband signal sampling,digital filtering and beamforming techniques,iso-flux pattern synthesis technique and fast direction of arrival(Do A)estimation technique for wide angle coverage and low sensitivity have been researched and simulated,respectively.Furthermore,the design of smart antenna processing system hardware circuit as well as the debugging and testing of the related interface circuit have been accomplished.According to the hardware circuit architecture and function allocation,the FPGA and DSP software implementation scheme design have been accomplished.The software design and implementation of the optimised digital filtering and decimation,digital beamforming,Do A estimation with tracking and beam weight calculation modules have also been completed on the hardware platform.Finally,software integration,test verification and performance evaluation of the above functional modules have been accomplished,including: multi-functional digital filtering,simultaneous multi-beam forming,element-level despreading processing and fast Do A estimation functions.Under the control of the host computer control software,preliminary test of system functions have also been carried out.