OFDM system identification based on m-sequence signatures in cognitive radio context

François-Xavier Socheleau (1) , Sébastien Houcke (2, 1) , Abdeldjalil Aissa El Bey (2, 1) , Philippe Ciblat (3)

1 SC - Département Signal et Communications
2 Lab-STICC_TB_CACS_COM
3 ENST - Ecole Nationale Supérieure des Télécommunications

In the context of cognitive radio, system identification is a crucial step towards radio environment awareness. In this paper, we present a new OFDM system identification method based on m-sequence (MS) specific characteristics. Thanks to their good random properties, m-sequences are commonly used in existing standards (such as Wifi or WiMAX) to modulate pilot tones for channel estimation and/or for synchronization purposes. We demonstrate that such sequences show extra-properties relevant to distinguish systems from each other and therefore advocate to generalize their use in a cognitive context. MS signatures are indeed of interest since they are able to discriminate OFDM based systems that have the same modulation parameters (intercarrier spacing, cyclic prefix duration, etc.). In order to detect these signatures, we conduct a hypothesis test based on the MS high order statistics. Detailed numerical examples demonstrate the efficiency of the proposed identification criterion and especially show its benefits compared to classical correlation methods.

Mots clés: Cognitive radio; Wimax; WLAN; WiFi

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

François-Xavier Socheleau, Sébastien Houcke, Abdeldjalil Aissa El Bey, Philippe Ciblat. OFDM system identification based on m-sequence signatures in cognitive radio context. PIMRC 2008 : 19th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, Sep 2008, Cannes, France. ⟨10.1109/PIMRC.2008.4699458⟩. ⟨hal-01770991⟩