Study of Smart Antenna Beamformer Based on Constant Modulus Algorithm

Abstract

Beam-forming algorithm is the key and theoretical basis of smart antenna. The constant modulus algorithm(CMA) needs no reference signals and has high efficiency on signal transmission channel, While, 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 CMA can be easily realized by combining the FPGA and DSP. According to this, a FPGA+DSP beam-forming system was designed based on CMA. Simulink results gave both the error variations of desired signals and gain changes of desired singals and interruptive signals in the iteration steps. In addition, the desired antenna orientation figures was also presented. At the same time, it was analyzed as well that the convergence speed and all the performance parameters of the proposed algorithm, and the results showed that the proposed method is feasible.