BER Improvement Effect of Optical Delay Insertion in ROF Ubiquitous Antenna for Road-to-Vehicle Wireless Coded CDM System

Abstract

This paper proposes the application of optical delay insertion and convolutional coding to Radio-on-Fiber ubiquitous antenna for Road-to-Vehicle wireless CDM (Code Division Multiplexing) system. In ubiquitous antenna system, the orthogonality of codes collapse, because a MS (Mobile Station) receives interference signals transmitted from different RBSs (Radio Base Station). So BER performance becomes worse. In order to solve this problem, we propose the application of convolutional coding. In addition, in ubiquitous antenna system, a MS sometimes receives signals transmitted from different RBSs at same chip timing. Therefore these signals become interference each other. In order to solve this problem, we propose the application of optical delay insertion as a MS does’t receive signals transmitted from different RBSs at same chip timing. In the case the distance between RBSs is 20[m] and chip rate is 32[Mcps], we can acquire the BER improvement all over the area by insertion of a 10[m] optical fiber.