Blind timing and carrier synchronisation in distributed multiple input multiple output communication systems

This study addresses the problem of joint blind timing and carrier synchronisation in a (distributed-M ) × N antenna system where the objective is to estimate theM carrier offsets, theM timing offsets and to recover the transmitted symbols for each of theM users given only the measured signal at the N antennas of the receiver. The authors propose a modular receiver structure that exploits blind source separation to reduce the problem into more tractable sub-problems of estimating individual timing and carrier offsets for multiple users. This leads to a robust solution of low complexity. The authors investigate the performance of the estimators analytically using modified Cramer–Rao bounds and computer simulations. The results show that the proposed receiver exhibits robust performance over a wide range of parameter values, even with worst-case Doppler of 200–300 Hz and frame size as small as 400 symbols. This work is relevant to future wireless networks and is a complete solution to the problem of estimating multiple timing and carrier offsets in distributed multiple input multiple output (MIMO) communication systems.