F. B. Serkin – Post-graduate Student, Moscow Aviation Institute (National Research University). E-mail: email@example.com
Purpose. The research of correlation properties of signals, which are generated on physical layer of IEEE 802.11b standard and analysis of possibility to use these signals for upgrading synchronization systems.
Design/methodology/approach. The MATLAB/Simulink model based on Wi-Fi frame generating and processing algorithms was designed. This model allows to research and analyze Wi-Fi frames, which are generated by following procedure. The information about type, length of the frame and synchronization preamble is added to frame on the physical layer of IEEE 802.11b. Then resulting packet is scrambled, modulated with Differential Binary Phase Shift Keying (DBPSK) and spreaded with eleven-chip Barker code.
Processing algorithm consists six parts: automatic gain control, coarse frequency synchronization, specific preamble search and frame synchronization mechanism, DBPSK demodulator, descrambler and frame parser.
Findings. Analysis of the model showed, that after frame generation operations the autocorrelation function of synchronization preamble has very low side lobes and narrow peak, which gives good opportunities for frame offset measurement. Based on this analysis the specific receive algorithm is described. This receive algorithm is based on idea of burst transmission so there is no classical symbol locked loop, and frequency locked loop is implemented before the main part of the signal processing algorithm. Such procedure allows to save power by disabling the main part of algorithm.
Research limitations/implications. The present work is a starting-point for further research of pseudo random sequences for use in frame synchronization systems.
Originality/value. Results of research will then be used in future analysis of synchronization systems upgrade methods.