Enhanced coverage through relay assisted carrier aggregation for cellular networks

Carrier aggregation (CA) is an important feature of next generation cellular networks to meet the growing demand for wireless broadband services from fast-growing mobile users. This also facilitates the efficient use of fragmented spectrum among users of varying data rates. However, this does bring in a number of new implementation challenges, among which energy efficiency along with ensuring coverage and capacity fairness for users becomes the fundamental challenge for such systems. This paper initially analyses the outage capacity of such systems for both intra- and inter-band CA. Then, relaying is proposed as an energy efficient technique for enhancing the capacity and coverage of such systems. In this context, the ergodic rate of a typical user is analysed for both single- and multi-flow relay assisted CA systems. Different band deployment configurations are also analysed and compared. Further, it is observed that relays can be utilised to boost the capacity of lower frequency component carriers ensuring better capacity fairness among the users.