Performance of smart antenna receivers implemented in different frequencies

The performance of directional RAKE receiver (DIRAKE) implemented in radio frequency, intermediate frequency and baseband is investigated as well as the numerical results. The DIRAKE is based on the smart antenna (SA) and traditional RAKE receiver, which results in the separation of signal from space domain. It is shown in the paper that the scheme of intermediate frequency has the highest performance cost, by which the multi-path interference can be restrained. For coherent demodulation unusable in baseband, interference would be amplified, which results in the fluctuation of performance. Though the performance of radio frequency scheme is best, it is too hard to realize in engineering.