New framework for interference and energy analysis of soft frequency reuse in 5G networks

Cellular networks are expanding massively due to high data requirements from mobile devices. This has motivated base station densification as an essential requirement for the 5G network. The implication is obvious benefits in enhanced system capacity, but also increased challenges in terms of interference. One important interference management technique which has been widely adopted in cellular networks is frequency reuse. In this article, an analysis is presented based on network interference and energy expended by base stations in downlink communication when Soft frequency reuse (SFR) is deployed. A framework is presented that captures the bandwidth overlaps in SFR across base station assignments, computes the interference probabilities arising and derives new performance equations which are verified using simulations. Results show an improvement of over previous SFR implementations that do not consider the interference probabilities. Thus, a more in-depth and accurate modelling of SFR in 5G networks is achieved. Furthermore, the downlink power allocation is investigated as against other parameters like the center ratio and edge bandwidth. The result shows that signal-to-interference-noise ratio (SINR) and spectral efficiency give different performance under energy consideration. A framework is developed on how to tune a base station to achieve desired network performance in user SINR or cell spectral efficiency depending on the operator’s preference.

Enhancing Cell Throughput & Area Spectral Efficiency Using Two Level Soft Frequency Reuse Technique

Heterogeneous networks consist of different characteristics of networks like small cells having low power deployed along with macro cells having high power. Interference is the major issue to degrade the quality of signal in the heterogeneous networks. Number of interference coordination techniques are implemented to minimize interference. One of the interference coordination technique is fractional frequency reuse (FFR) and soft frequency reuse (SFR). In this paper two level Soft Frequency Reuse technique is implemented along with sectors. Parameters such as area spectral efficiency and cell edge throughput are calculated and compared with conventional FFR and Multi-level FFR technique with 6 sectoring. Better results are analyzed while simulating in the network model. Cell edge throughput improved to 54 Mbps, average cell throughput improved to 667 Mbps, peak data throughput improved to 76.7 Mbps and area spectral efficiency improved to 70.3 bits/sec/Hz/cell.