Research on the Performance of SA in CDMA Application

Considering the effect of the transmitting data, this paper analyzes the performance of circular SA with 8 array elements (AE) in different application scenarios. Double code-channels pointing to the same direction is the basic mode of TDD-CDMA when transmitting voice signals. However, our research has discovered that the system working in that mode is unstable. If more code-channels pointing to different direction are used, then, according to the combination of the transmitting data, the direction for the major beam-lobe will change greatly, which is hard to forecast. Moreover, when the working code-channels rise to 8 ones, the directional diagram of the beam will be similar with that of an un-directional antenna. Anyway, when using circular SA with 8 AE in TDD-CDMA system, it will be difficult to ensure the stability of directional transmission.