Improving performance of DS/SS-IVC under shadowing environment using LMS adaptive circular array antenna

In this paper, an adaptive circular array antenna is applied to DS/SS (Direct Sequence / Spread Spectrum) IVC (Inter-Vehicle Communication) under shadowing environment. The DS/SS scheme is an attractive technique for the IVC system because it has advantages for CDMA (Code Division Multiple Access) capability and so on. However, the near-far problem is occurred in the DS/SS scheme. Shadowing the radio paths by large vehicles is also significant problem for the IVC system. To solve those problems, a LMS (Least Mean Square) adaptive circular array antenna is proposed. The array antenna can be controlled its directivity when the receiving vehicle knows the information of the target vehicle. The PER (Packet Error Rate) and the throughput performances are evaluated. And the performances are compared with the ordinary system by using omini-directional antenna. From the simulation results, the adaptive circular array antenna is effective for the near-far problem and influence of shadowing in the DS/SS TVC system.