Joint oversampled carrier and time-delay synchronization in digital communications with large excess bandwidth

Jordi Vilà Valls (1, 2) , Laurent Ros (3) , Jean-Marc Brossier (3)

1 UPC - Universitat Politècnica de Catalunya = Université polytechnique de Catalogne [Barcelona]
2 GIPSA-lab - Grenoble Images Parole Signal Automatique
3 GIPSA-CICS - GIPSA - Communication Information and Complex Systems

This paper deals with the joint estimation of the pair dynamical carrier phase/Dopplershift and the time-delay in a digital receiver. We consider a Binary Offset Carrier shaping function as used in satellite positioning, which is a time-limited pulse with a large excess bandwidth, and a Data Aided synchronization scenario, where we have a constant time-delay and a Brownian phase evolution with a linear drift. The proposed study is relative to the use of an oversampled signal model after matched filtering, leading to a colored reception noise and a non-stationary power signal. The contribution of this paper is twofold. First, we derive the Hybrid Crame'r-Rao Bound for the joint phase/Doppler estimation problem. Then, we propose a method for the joint timedelay/carrier synchronization, which couples an Extended Kalman Filter and an Expectation-Maximization type algorithm. Our numerical results show the potential gain of using the oversampled signal for carrier synchronization, obtaining better performances than using a classical synchronizer, and good time-delay estimation.

Mots clés: Carrier synchronization; Time-delay synchronization; Hybrid Crame'r-Rao bound; Non-linear filtering Extended Kalman filter; Expectation-maximization Oversampling GNSS BOC

Domaines: Traitement du signal et de l'image [eess.SP]; Traitement du signal et de l'image [eess.SP]

Jordi Vilà Valls, Laurent Ros, Jean-Marc Brossier. Joint oversampled carrier and time-delay synchronization in digital communications with large excess bandwidth. Signal Processing, 2012, 92 (1), pp.76-88. ⟨10.1016/j.sigpro.2011.06.008⟩. ⟨hal-00617911⟩