Transmit antenna array techniques for cellular CDMA systems

Adaptive antenna arrays can be employed to improve the transmission quality and thus to increase the capacity of wireless communication systems. We address the transmit antenna array techniques for base-to-mobile (downlink) transmission in frequency-division-duplex (FDD) based cellular CDMA systems. A new criterion for transmit weight estimation is developed, which is based upon maximizing the transmit signal-to-interference-plus-noise ratio (SINR) and using downlink channel responses estimated by a probing feedback approach. Computer simulations show that the new transmit antenna array technique is effective for improving the capacity of the wireless communication systems.