Mixing of Technologies for Adaptive Beamforming Implementation

This paper describes the recent trends in the hardware implementation of smart antenna beamforming networks. Two receiver subsystems are developed and tested based on different beamforming concepts. One is a four-element array direct conversion receiver with digital beamforming and the other is an eight-element array heterodyne receiver with hybrid analog-digital beamforming. Experiments are conducted using these two systems for DOA estimation, beamshaping, demonstration of SDMA and BER measurements. The pros and cons of these two of beamforming implementations are discussed. It is concluded that the mixing of analog and digital beamforming technologies brings the maximum benefits to the system performance.