Performance improvement of cross-shaped urban microcellular systems with switched-beam antennas

A four-sector cross-shaped urban microcellular system with intelligent switched-beam antennas is proposed. Each sector covers a street block with a base station located at an intersection and an intelligent beam-switching scheme is used to locate mobile users in the most suitable beam coverage. Due to directional beam patterns and waveguide effects of tall buildings, radio signals along vertical and horizontal streets do not interfere with each other. Therefore, a channel can be reused simultaneously in multiple neighboring cells as long as cochannels do not encounter each other along the line of sight. The proposed system increases the system capacity more than three times with a blocking probability of 1% and considerably reduces handoff traffic when compared with conventional cross-shaped microcellular systems with an omnidirectional beam pattern.