Carrier phase synchronization ofOF multiple distributed nodes in a wireless network

In this work we present a method for achieving global carrier phase synchronization in a wireless network of distributed, autonomous nodes. Other authors who have investigated this problem mainly focus on a master/slave strategy based on one master broadcasting a sinusoidal reference signal to all slaves. We follow a slightly different approach where the slaves concurrently or sequentially transmit a broadband sequence to the master. Receiving the conjugate complex of the bounced-back signal, each slave can locally determine the phase difference between its own and the master´s local oscillator (LO). This information suffices to allow for coherent cooperation. The broadband nature of the used sequences makes our approach robust to deep fades in a frequency-selective environment. We revisit the popular strategy for global carrier phase synchronization using the sinusoidal reference and compare it to our own approach. A potential application then stresses the benefits of our scheme.