A high-capacity wireless network by quad-sector cell and interleaved channel assignment

In this paper, we propose an improved sectorization scheme, called narrow-b eam quad-sector cell (NBQC) for cellular networks, in which each cell is di vided into four sectors and each sector is covered by a 60 degrees antenna. The NBQC structure allows easy implementation of the concept of interleave d channel assignment (ICA), which can take full advantage of antenna direct ivity, With ICA, the NBQC system can enhance the system performance from se veral perspectives. First, the NBQC has better coverage performance than th e current three-sector cellular architecture. Second, we demonstrate that i n a typical radio environment, the NBQC system can achieve a reuse cluster size N = 2 with the signal-to-interference ratio (SIR) as high as 11 dB in 90% of the cell area, which is a 3-5-dB improvement over the existing cellu lar architectures. Third, as compared to the most advanced three-sector clo ver-leaf cell architecture with reuse cluster size N = 3, the NBQC system w ith ICA can achieve reuse cluster size N = 2 with very slight degradation i n SIR performance, thereby still improving system capacity by about 40% ove r a wide range of ninetieth percentile SIR requirements.