Qualitative analysis for coverage probability and energy efficiency in cognitive‐femtocell networks under macrocell infrastructure

J Ghosh,S Dhar Roy

doi:10.1049/el.2015.0171

Abstract

The network coverage and energy efficiency issues in heterogeneous cognitive-femtocell networks over the macrocell network is studied. Cognitive functions in wireless network nodes are serviceable with the macrocell infrastructure to achieve a balance between two desirable but incompatible features: coverage and energy efficiency. There are two basic but related aspects of cognitive radios (CRs) in the context of wireless communications: optimum CRs for energy efficiency and the act of the functioning of CRs with energy efficiency. To fully utilise the cognitive capability, a dual-tier network architecture is assumed where both the macrocell and the femtocell have a bearing on the cognitive capability. Owing to the salient features of femtocells, they can improve the coverage and enhance the spectrum efficiency by reutilising the frequency spectrum allocated to the macrocell, although, the resulting intercell interference accompanied by the same frequency coverage cannot be underestimated. The effectiveness of the scheme is verified by extensive Matlab simulation.

Highlights

Energy-efficient networks are required in order to protect the environment, cope with global warming, and facilitate sustainable communication growth [1]
The coverage probability increases gradually at a certain point of time for a particular number of users and it decreases with a further increase in the number of users by maintaining the same slope where the coverage probability is relatively higher for the 100 × 100 m2 grid as compared with the 120 × 120 m2 grid at any instant
The coverage probability is higher for a large coverage radius at any instant for a specific number of users

Summary

Introduction

Energy-efficient networks are required in order to protect the environment, cope with global warming, and facilitate sustainable communication growth [1]. Owing to its small transmit–receive path and low transmit power property, the femtocell can reduce the consumption of energy, elongate handset battery life, and enhance the efficiency of network coverage in terms of quality of service (QoS) [4]. In this Letter, we consider energy efficiency in the context of frequency band sharing and power assignment in heterogeneous CR networks with femtocells. As both CR and the femtocell are encouraging technologies to improve energy efficiency in wireless networks, cooperation between them will improve further research. The purpose is to model a sensible interference-limited environment, and the receiver accessibility radius is accounted to be much higher than the cell radius, that is, Rac. Unity gain omnidirectional antennas are assumed throughout the whole Letter. The loss parameter L is expressed in terms of propagation loss, shadowing, and multipath fading

Rxz dxz

Results and discussion

Conclusion