Impact of Noisy Carrier Phase Synchronization on Linear Amplify-and-Forward Relaying

We consider a distributed wireless network where amplify-and-forward relays assist the communication between multiple source/destination pairs. To provide a global phase reference at the relays it suffices for each relay to know the phase difference between its own local oscillator (LO) and the LO of a global master node. Based on a scheme to achieve this, we characterize the phase synchronization inaccuracy caused by additive signal noise and LO phase noise. It turns out that relay phase noise only has a limited impact on the performance. Merely the phase uncertainty during the time between phase estimation and channel measurements at the relays affects the system. Finally, we quantify the impact of phase estimation inaccuracy on multiuser zero-forcing relaying.