The Hardware Platform Based On Software Radio

SDR(Software Defined Radio) is the development direction of wireless communication system, which enables the implementation of new wireless communication systems through the software without any change on the hardware. At present, the evolution of 3G to LTE or a more advanced communication system uses the SDR.This paper describes the basic principles of wireless communication systems and the architecture of relevant required chips in the hardware platform design. And the paper mainly discusses the design and implementation of methods of the pipelined and modular hardware platform based on SDR, as well as the realization method of the baseband signal of transmitter and receiver processing algorithm. On the hardware platform, the paper implements multi-modulation and multi-frequency transmission signals including ASK, BPSK, QPSK, and 16QAM, and accomplishes the signal synchronization for BPSK and QPSK.The hardware platform is divided into four modules, which including baseband processing module of transmitter, D/A and modulation module, demodulation and A/D module and baseband processing module of receiver. The transmitter consists of baseband processing modules of transmitter and D/A and modulation module, realized by EP3C25Q240C8N and AD9777 chips. The receiver consists of demodulation and A/D module and baseband processing module of receiver, realized by AD8348, AD8362, AD9218 and EP3C25Q240C8N chips.Considering low power, low-cost and high-performance features, the design selects FPGA chip as the platform of transceiver baseband processing algorithms implementation. By programming on the FPGA chip, the transmitter can generate signals which run at different rates and different modulation modes and the receiver can realize the different synchronization algorithms. AD9777 is selected as the main chip on D/A and modulation module, because it has a strong configurable function. Different frequency digital carriers can be generated by configuring the AD9777. AD8348, AD8362 and AD9218 chips are used to realize the demodulation and A/D module, because these chips can not only match the transmitter specifications, but also improve system stability. All communication specifications have satisfied the SDR's basic requirements through a large number of system tests.