Implementation of Methods to Reduce Self Interference in Multihop Wireless Networks Deepthi K.*, Sumalatha V. Department of ECE, JNTU College of Engineering, Anantapur, Andhra Pradesh, India *deepthi.kottam @gmail.com
Online published on 27 June, 2017. Abstract Full-duplex relaying is more spectrally efficient than half-duplex relaying as only one channel use is needed per two hops. However, it is crucial to minimize relay self-interference to render full duplex feasible. For this purpose, we analyze abroad range of multiple-input multiple-output (MIMO) mitigation schemes: natural isolation, time-domain cancellation, and spatial suppression. Cancellation subtracts replicated interference signal from the relay input while suppression reserves spatial dimensions for receive and transmit filtering. Spatial suppression can be achieved by antenna subset selection, null-space projection, i.e., receiving and transmitting in orthogonal subspaces, or joint transmit and receive beam selection to support more spatial streams by choosing the minimum eigen modes for overlapping subspaces. In addition, minimum mean square error (MMSE) filtering can be employed to maintain the desired signal quality, which is inherent for cancellation, and the combination of time and spatial-domain processing may be better than either alone. Targeting at minimal interference power, we solve optimal filters for each scheme in the cases of joint, separate and independent design. The performance of mitigation schemes is evaluated and compared by simulations. The results confirm that self-interference can be mitigated effectively also in the presence of imperfect side information. Top Keywords Amplify-and-forward (AF), antenna selection(AS), beam selection (BS), decode-and-forward(DF), full-duplex, interference cancellation, multiple-input multiple-output (MIMO)relay, self-interference. Top |