Performance enhancement by narrow-beam quad-sector cell and interleaved channel assignment in wireless networks

We propose an improved sectorization scheme for cellular networks, called narrow beam quad-sector cell (NBQC), in which each cell is divided into 4 sectors and each sector is covered by a 60° antenna. The NBQC architecture has a better coverage performance than the current 3-sector cellular architecture. More importantly, the NBQC architecture allows easy implementation of the powerful interleaved channel assignment (ICA) scheme. Because of taking full advantage of the antenna directivity, the NBQC architecture with the ICA scheme can improve the signal to interference ratio (SIR) performance, thereby increasing the system capacity significantly. Our results show that in a typical radio environment, the NBQC system with the ICA scheme can achieve a reuse factor N=2 with the 90 percentile of SIR as high as 11 dB, which represents 3 to 5 dB SIR improvement or about at least 40 percent system capacity improvement over current cellular networks.