Experimental Verification of the Hybrid Smart Antenna Algorithm With Modulated Waveforms

The hybrid smart antenna approach utilizes a subset of array elements selected according to the receive signal strengths to perform beamforming, thus improving the computational efficiency, and reducing the hardware implementation cost. The previous implementations and published experimental results of this algorithm have been based on continuous-wave (CW) transmit signals, and without modulation. In order to verify the operation of the hybrid smart antenna algorithm with modulated waveforms, the developed 2.4- and 60-GHz testbeds are modified to generate and receive data modulated waveforms. The modifications also include the use of preamble bits at the beginning of each data frame transmitted, and implementation of a sliding window correlator at the receiver to synchronize with the data frames. Binary phase shift keying (BPSK) modulation is used with a 1 megabit per second (Mb/s) data rate for information transfer. The obtained beam patterns agree well with the theoretical results thus verifying the developed hybrid smart antenna algorithm.