Cooperative spectrum sensing with multihop multibranch incremental relaying

Abstract

In this paper, we propose a new Spectrum Sensing (SS) algorithm with multihop multibranch Incremental Relaying (IR). When the Signal to Noise Ratio (SNR) between Primary User (PU) and Fusion Node (FN) is larger than a predefined threshold T, SS is performed at FN using the energy detector based on the received signal from PU. When the SNR between PU and FN is less than T, relays will be activated and amplify the PU signal to FN using multihop relaying. SS uses both the direct signal from PU and relayed one using Amplify and Forward (AF) relays. When multiple branches are available, we suggest two protocols with IR. In the first one, the best branch will be activated when the SNR between PU and FN is less than T. In the second protocol, relays of all branches transmit over orthogonal channels using multihop relaying when the SNR between PU and FN is less than T.