Throughput enhancement for multi-hop decode-and-forward protocol using interference cancellation with hardware imperfection
Phu Tran Tin, Nguyen Thanh Luan, Tan N. Nguyen, Minh Tran, Tran Trung Duy
Abstract
In this paper, we propose three interference cancellation based multi-hop decode-and-forward (DF) relaying protocols to enhance end-to-end system throughput under constraint of half-duplex and hardware imperfection. In the first proposed protocol, the successive interference cancellation technique is used at each hop to send N signals from a source to a destination. Hence, the first proposed protocol can increase N times of the data rate, as compared with the corresponding conventional multi-hop DF relaying protocol in which only one source data is hop-by-hop relayed to the destination via M intermediate hops. In the second one, the source and relays can at the same time transmit their signals, and the interference cancellation can be performed to remove co-channel interference components. Therefore, the data rate of the second proposed protocol can increase M/2 times, as compared with the corresponding conventional protocol. The third proposed protocol is an efficient combination of the first and second proposed ones, and hence its data rate is higher N times than the second proposed one. Moreover, the imperfect co-channel interference cancellation is also considered in the second and third protocols. For performance evaluation, we derive exact closed-form expressions of the end-to-end throughput for three proposed protocols over Nakagami-m fading channel. We also perform simulations to verify the analytical formulas, and propose an simple transmit power allocation strategy to mitigate impact of the co-channel interference and imperfect co-channel interference cancellation.