Implementation Of Adaptive Beamforming Algorithm In Smart Antenna

In recent years, with the rapid development of mobile communications, the amount of consumer increased quickly, which leads to the increasingly stress of spectrum resource. Meanwhile Multiple Access Interference, Common Channel Interference and multipath fading limit the further improvement to the channel capacity and quality of communication. Smart antenna and space filtering have brought new ideas to the solution of solving these problems. Since the smart antenna technique could overcome these problems with the DOA which is its spatial characteristic, the use of smart antenna could not only guarantee the quality of communication, but also raise the region of covering and the system capacity.The core of smart antenna technology is the adaptive beamforming algorithm. The performance of the whole system is directly affected by the convergence performance and computation complexity of the adaptive algorithms.In this paper, the principle of smart antenna are proposed firstly, and then the features, mathematical model and simulation methods of mobile communication are presented. Three adaptive algorithms (LMS,RLS and CMA) are discussed. Then the three algorithms are simulated by MATLAB respectively. In the same environment, the three algorithms are compared.Finally, the digital beamforming device have been designed by combining the FPGA and DSP. FPGA can process multiple parallel signals quickly, and DSP is a signal processing method with properties of fast calculation, flexible addressing mode and powerful communication mechansim. As a result, the beamforming system can be easily realized. In order to create eight antenna signals which are down converted,a high-speed multi-channel data acquisition system are designed. The resulting data is important to the algorithm and experimental researches.