Performance Study of W-CDMA Adaptive Array Antennas

The effect of the antenna geometry and the adaptive algorithm on the performance of a W-CDMA adaptive array antenna for mobile terminals is investigated experimentally. A W-CDMA receiving system for a 4-element array antenna is developed. The adaptive algorithm and the array antenna configuration are changed according to the requirement of the investigation. The performance of the system including synthesized pattern, adaptive weight and bit-error-rate (BER) characteristics are measured for the performance analysis. Results show that signal-to-interference ratio (SIR) can be greatly improved by 6 to 10 dB compared with the single antenna when BER is equal to 10^-3. BER of the single monopole with a reflector is lower than that of the single monopole because the monopole with reflector has a higher gain in the direction of the desired wave. However, the SIR improvement of the monopole array is larger than that of the monopole array with a reflector because the array element gain of the monopole to the direction of the interference is larger. It seems that array elements which have homogeneous radiation pattern and high radiation efficiency are suitable to the adaptive array antennas