A key problem in the design of cloud radio access networks (CRANs) is that ofdevising effective baseband compression strategies for transmission on thefronthaul links connecting a remote radio head (RRH) to the managing centralunit (CU). Most theoretical works on the subject implicitly assume that theRRHs, and hence the CU, are able to perfectly recover time synchronization fromthe baseband signals received in the uplink, and focus on the compression ofthe data fields. This paper instead dose not assume a priori synchronization ofRRHs and CU, and considers the problem of fronthaul compression design at theRRHs with the aim of enhancing the performance of time and phasesynchronization at the CU. The problem is tackled by analyzing the impact ofthe synchronization error on the performance of the link and by adoptinginformation and estimationtheoretic performance metrics such as therate-distortion function and the Cramer-Rao bound (CRB). The proposed algorithmis based on the Charnes-Cooper transformation and on the Difference of Convex(DC) approach, and is shown via numerical results to outperform conventionalsolutions.
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