Cooperative Code Acquisition based on the P2P Paradigm

Wireless cooperation among smart devices is a very clear trend, with applications in innumerable domains. In this paper, we address in particular applications in the field of assisted navigation and positioning with emphasis on the code acquisition procedure. Indeed, the great diffusion of hybrid navigation-communication (NAV-COM) devices provides the means for developing new cooperation concepts that rely on the exploitation of the existing communication links among receivers and the exchange of assistance information. The concept of Peer-to-Peer (P2P) cooperation relies in fact on the idea that receivers belonging to the same network have positions which are correlated to each other; thereby, satellite signals are received with similar time delays. The exchange of timing information and the sharing of resources can thus become essential also for GNSS receiver initial operations as for achieving increased acquisition capabilities in very low signal-to-noise ratio (SNR) scenarios. In the present work an innovative Cooperative Code Acquisition (CCA) technique relying on the sharing of primary code phase information is introduced. Assuming that the peers in the network are aligned to a common time reference, the aim of this technique is to increase the probability of detection (Pd) with positive impacts on the Mean Acquisition Time (MAT). The proposed CCA algorithm is performed in two consecutive stages: a Coarse Acquisition Stage (CAS), in which each peer computes locally its autocorrelation values and a Refinement Stage (RS) in which the results obtained by several receivers in the network are combined together yielding improved performance.