Research And FPGA Implementation Of Smart Antenna Array And DOA Estimation Arithmetic

With the development of the technology of mobile communication, smart antenna becomes a key technology of 3G by it's improvements and benefits such as capacity increase range increase security and reduced multipath propagation. Smart antenna is a complex system including array antennas digital signal processing unit and adaptive arithmetic unit. The array antennas are made of several antennas placed in special on a definite principle, the function of which is transmitting and receiving radio. The digital signal processing unit is used to process the signals received from the array hardware of which is included of DSP and FPGA. The adaptive arithmetic unit adaptively leads the main lobe of array to the direction of expected signal.In this paper two sections array and arithmetic of DOA are researched on the eight elements array antennas and important arithmetic is run on the FPGA.Firstly by analyzing the directional characteristic of the line array and the circuit array we advance a new form of array namely elliptic array antenna, proving that the line array and the circuit array can be consolidated in the elliptic array and deducting the uniform expression for array characteristic, at the same time discussing deeply the effects of the number of the array element to the directional characteristic of the array antennas. Inclusion is as following: It can increase the gain of main lobe and restrain the side lobe to add the numbers of array. For the line array the impacts are obvious and for the circuit array it is obvious to restrain the side lobe.Secondly the paper studies the important arithmetic of DOA especially MUSIC , and compares the performance of different arrays through the all-purpose programs on Matlab. Aiming at the problem of validation on the FPGA we program the UART between PC and FPGA so the operation result can be return to the PC.