Improved OVSF/CDMA Code Assignment in MANET Using Directional Antenna

CDMA (code division multiple access) is one of the most important methods of multiple access since it can provide a higher capacity compared to analog equipment and digital platforms. OVSF (orthogonal variable spreading factor) codes are variable bit rate code words that not all of them are orthogonal to each other. The code assignment variant used to assign these codes to network nodes is called prefix-free vertex coloring. Code assignment algorithm in MANET tries to maximize throughput and/or bottleneck. In this paper, we show that directional antennas can help us to simplify the interference graph and reduce the conditions that code assignment algorithm should maintain. Simulation results show a significant increase in throughput and bottleneck