Một tỷ lệ tái sử dụng lớn hơn không nhất thiết mang lại chất lượng tín hiệu tốt hơn (tàu sân bay để can thiệp tỷ lệ). Điều này sẽ phụ thuộc vào các điều kiện LOS và NLOS kinh nghiệm của các trạm điện thoại di động trong các cụm khác nhau. | Because of the inherent asymmetry of the square grid there is not a direct relation among the reuse ratio the signal quality and the cluster size as was the case for the hexagonal grid. A larger reuse ratio does not necessarily yield better signal quality better carrier-to-interference ratio . This will greatly depend on how the LOS and NLOS conditions are experienced by the mobile stations in the various clusters. Positioning of the Co-Cells The exact positions of the co-cells are given in Appendix D. Interference in Narrowband and Wideband Systems Narrowband and wideband systems are affected differently by interference. In narrowband systems interference is caused by a small number of high-power signals. Moreover macrocellular and microcellular networks undergo different interference patterns. In addition whereas in macrocellular systems uplink and downlink present approximately the same interference performance in microcellular systems the interference performance of uplink and downlink is rather dissimilar. In both cases the uplink performance is always worse than the downlink performance but the difference between the performances of both links is drastically different in microcellular systems. For macrocellular systems the larger the reuse pattern the better the interference performance. For microcellular systems it can be said that in general the larger the reuse pattern the better the performance. In wideband systems interference is caused by a large number of low-power signals. In such a case the traffic profile as well as the channel activity have a great influence on the interference. Here again uplink and downlink perform differently. The interference performance of cellular systems is investigated here in terms of the carrier-to-interference ratio C11 and the efficiency of the frequency reuse f . These are explored in the following sections. Interference in Narrowband Macrocellular Systems Propagation in a macrocellular environment is .
